Automated method and apparatus for mixing mud for use in well operations

Claim 1

An apparatus for mixing material, said apparatus comprising: reservoir means; first supply means, including a transfer reservoir means, for conveying a high-density material, at a relative low rate, toward said reservoir means; second solids transfer supply means for conveying a high-density material toward said reservoir means at a relative high rate; means for pneumatically conveying said high-density material to said first and second supply means whereby said pneumatic means provides an enclosed system thereby preventing hazardous dust conditions; and density measuring means operable to measure the density of material mixed in said reservoir means, said density measuring means, including a combination of photon energy levels and further including a radioactive density-measuring means operable, substantially independent of the amount of said highdensity material in said mixed material, to indicate mixed material density, with the calibration of said radioactive density-measuring means being substantially the same when each of said first and second supply means is independently supply material to said reservoir means.

Claim 2

An apparatus for mixing material, said apparatus comprising: reservoir means; first supply means, including a transfer reservoir means, for conveying a high-density material, at a relative low rate, toward said reservoir means; second solids transfer supply means for conveying a high-density material toward said reservoir means at a relative high rate; means for pneumatically conveying said high-density material to said first and second supply means whereby said pneumatic means provides an enclosed system thereby preventing hazardous dust conditions; and density measuring means operable to measure the density of material mixed in said reservoir means, said density measuring means, including a combination of photon energy levels and further including a radioactive density-measuring means operable, substantially independent of the amount of said highdensity material in said mixed material, to indicate mixed material density, with the calibration of said radioactive density-measuring means being substantially the same when each of said first and second supply means is independently supply material to said reservoir means.

Claim 3

An apparatus for mixing mud to be used in well-drilling operations, said apparatus comprising: mud-mixing, reservoir means; first supply means, including a transfer reservoir means, for supplying a high-density, pulverulent material, at a relative low rate, to said mud-mixing reservoir means; second solids transfer supply means for supplying a high-density pulverulent material to said mud-mixing reservoir means at a relatively high rate; density-measuring means operable to measure the density of mud mixed in said mud-mixing reservoir means, said density-measuring means including a combination of photon energy levels and further including a radioactive density-measuring means operable, substantially independent of the composition of said mud, to indicate mud density, with the calibration of said radioactive density-measuring means being substantially the same when each of said first and second supply means is independently supplying pulverulent material to said mud-mixing reservoir means; means responsive to said density-measuring means for alternately regulating the flow of pulverulent material through said first and second supply means; and pneumatic conveying means for impelling pulverulent material through each of said first and second supply means whereby said pneumatic conveying means, providing an enclosed high-capacity mixing system, minimizes the generation of dust.

Claim 4

An apparatus for mixing mud to be used in well-drilling operations, said apparatus comprising: mud-mixing, reservoir means; first supply means, including a transfer reservoir means, for supplying a high-density, pulverulent material, at a relative low rate, to said mud-mixing reservoir means; second solids transfer supply means for supplying a high-density pulverulent material to said mud-mixing reservoir means at a relatively high rate; density-measuring means operable to measure the density of mud mixed in said mud-mixing reservoir means, said density-measuring means including a combination of photon energy levels and further including a radioactive density-measuring means operable, substantially independent of the composition of said mud, to indicate mud density, with the calibration of said radioactive density-measuring means being substantially the same when each of said first and second supply means is independently supplying pulverulent material to said mud-mixing reservoir means; means responsive to said density-measuring means for alternately regulating the flow of pulverulent material through said first and second supply means; and pneumatic conveying means for impelling pulverulent material through each of said first and second supply means whereby said pneumatic conveying means, providing an enclosed high-capacity mixing system, minimizes the generation of dust.

Claim 5

An apparatus for mixing mud to be used in well-drilling operations, said apparatus comprising: mud-mixing, reservoir means; first supply means for supplying a pulverulent barite-containing material, at a relatively low rate, to said mixing reservoir means; second supply means for supplying a pulverulent barite-containing material to said mixing reservoir means at a relatively high rate; density-measuring means operable to measure the density of mud in said mixing reservoir means, said density-measuring means including radioactive density-measuring means operable, substantially independent of the composition of said mud, to indicate mud density, with the calibration of said radioactive density-measuring means being substantially the same when each of said first and second supply means is independently supplying pulverulent material to said mixing reservoir means; said density-measuring means including a source Of photons having a photon energy of between about 0.6 and about 2 Mev. positioned adjacent a vertical flow of said mud, means for collimating the emission of photons from said source en route to said mud, shielding means for substantially blocking the passage of photons issuing from said mud which have a photon energy level of less than about 0.3 Mev. and attenuating the passage of photons issuing from said mud having a photon energy level of less than about 0.45 Mev. by at least twice the degree of attenuation of photons issuing from said mud which have a photon energy level of about 0.6 Mev. or greater, scintillation counting means, means for impinging photons which have been subjected to said blocking and attenuating on said scintillation counting means, and means maintaining a lower discrimination level of said scintillation counting means at least as low as about 0.05 Mev.; means responsive to said density-measuring means for alternately regulating the flow of pulverulent material through said first and second supply means; and pneumatic conveying means for impelling pulverulent material through each of said first and second supply means.

Claim 6

An apparatus for mixing mud to be used in well-drilling operations, said apparatus comprising: mud-mixing, reservoir means; first supply means for supplying a pulverulent barite-containing material, at a relatively low rate, to said mixing reservoir means; second supply means for supplying a pulverulent barite-containing material to said mixing reservoir means at a relatively high rate; density-measuring means operable to measure the density of mud in said mixing reservoir means, said density-measuring means including radioactive density-measuring means operable, substantially independent of the composition of said mud, to indicate mud density, with the calibration of said radioactive density-measuring means being substantially the same when each of said first and second supply means is independently supplying pulverulent material to said mixing reservoir means; said density-measuring means including a source Of photons having a photon energy of between about 0.6 and about 2 Mev. positioned adjacent a vertical flow of said mud, means for collimating the emission of photons from said source en route to said mud, shielding means for substantially blocking the passage of photons issuing from said mud which have a photon energy level of less than about 0.3 Mev. and attenuating the passage of photons issuing from said mud having a photon energy level of less than about 0.45 Mev. by at least twice the degree of attenuation of photons issuing from said mud which have a photon energy level of about 0.6 Mev. or greater, scintillation counting means, means for impinging photons which have been subjected to said blocking and attenuating on said scintillation counting means, and means maintaining a lower discrimination level of said scintillation counting means at least as low as about 0.05 Mev.; means responsive to said density-measuring means for alternately regulating the flow of pulverulent material through said first and second supply means; and pneumatic conveying means for impelling pulverulent material through each of said first and second supply means.

Claim 7

An apparatus for mixing material, said apparatus comprising: mixing reservoir means; first discharge conduit means extending from said mixing reservoir means; density-measuring means operable to measure the density of material through said first discharge conduit means; return conduit means included in said first discharge conduit means and operable to return a portion of material from said first discharge conduit means to said mixing reservoir means; material supply means including second, discharge conduit means operable to discharge material from said supply means; first, relatively low-capacity, mixing means for supplying material to said mixing reservoir means, said first mixing means including transfer reservoir means, first branch conduit means for conveying material from said second discharge conduit means of said supply means into said transfer reservoir means, first means responsive to said density-measuring means for controlling the rate of discharge of material from said transfer reservoir means into said mixing reservoir means, second, relatively high-capacity, mixing means for supplying material to said mixing reservoir means, said second mixing means including second branch conduit means communicating with said second discharge conduit means of said supply means, said second branch conduit means bypassing said transfer reservoir means, second means, operable in response to said density-measuring means, to control a flow of air and material through said second branch conduit means en route to said mixing means; and selectively operable actuating means for actuating said first and second mixing means.

Claim 8

An apparatus for mixing material, said apparatus comprising: mixing reservoir means; first discharge conduit means extending from said mixing reservoir means; density-measuring means operable to measure the density of material through said first discharge conduit means; return conduit means included in said first discharge conduit means and operable to return a portion of material from said first discharge conduit means to said mixing reservoir means; material supply means including second, discharge conduit means operable to discharge material from said supply means; first, relatively low-capacity, mixing means for supplying material to said mixing reservoir means, said first mixing means including transfer reservoir means, first branch conduit means for conveying material from said second discharge conduit means of said supply means into said transfer reservoir means, first means responsive to said density-measuring means for controlling the rate of discharge of material from said transfer reservoir means into said mixing reservoir means, second, relatively high-capacity, mixing means for supplying material to said mixing reservoir means, said second mixing means including second branch conduit means communicating with said second discharge conduit means of said supply means, said second branch conduit means bypassing said transfer reservoir means, second means, operable in response to said density-measuring means, to control a flow of air and material through said second branch conduit means en route to said mixing means; and selectively operable actuating means for actuating said first and second mixing means.

Claim 9

An apparatus for mixing mud for use in well-drilling operations, said apparatus comprising: mixing reservoir means; first discharge conduit means extending from said mixing reservoir means; pump means operable to convey mud through said first discharge conduit means; density-measuring means connected with said first discharge conduit means and operable to measure the density of mud flowing therethrough; return conduit means included in said first discharge conduit means and operable to return a portion of mud flow, downstream of said density-measuring means, from said first discharge conduit means to said mixing reservoir means; solid material supply means including air pressure containing, and enclosure-defining wall means operable to support a mass of pulverulent material, means for supplying pressurized air to the interior of said enclosure defining wall means, with said wall means being operable to maintain superambient pressure within said wall means, and second, discharge conduit means operable to disCharge pressurized air and pulverulent material from said supply means; first, relatively low-capacity, mixing means for supplying pulverulent material to said mixing reservoir means, said first mixing means including transfer reservoir means, first branch conduit means for conveying pressurized air and pulverulent material from said second discharge conduit means of said solid material supply means into said transfer reservoir means, first vane means defining a series of mutually isolated, rotatable pockets for discharging pulverulent material from said transfer reservoir means to said mixing reservoir means, said first vane means defining a seal between the interior of said transfer reservoir means and said mixing reservoir means, first means responsive to said density-measuring means for controlling the rate of discharge of pulverulent material from said transfer reservoir means by said first vane means, control means for controlling said conveying of pressurized air and pulverulent material through said first branch conduit means to said transfer reservoir means so as to regulate the amount of pulverulent material in said transfer reservoir means, first return branch conduit means communicating with said return conduit means, comingling means for comingling pulverulent material discharged by said first vane means and mud passing through said first return branch conduit means, said comingling means including first jet-defining means operable to form mud flowing through said return conduit means into a jet stream operable to impel pulverulent material discharged by said first vane means; second, relatively high-capacity, mixing means for supplying pulverulent material to said mixing reservoir means, said second mixing means including second branch conduit means communicating with said second discharge conduit means of said solid material supply means, said second branch conduit means bypassing said transfer reservoir means, valve means, operable in response to said density-measuring means, to control a flow of pressurized air and pulverulent material through said second branch conduit means, outlet means for discharging pressurized air and pulverulent material from said second branch conduit means toward said mixing reservoir means, second return branch conduit means communicating with said return conduit means, annular stream-defining means communicating with said second return branch conduit means and operable to define an annular flow of mud encircling pressurized air and pulverulent material discharging from said outlet means; additive supplying means including additive material reservoir means, second vane means operable to define a series of mutually isolated rotatable pockets for discharging segregated quantities of additive material from said additive material reservoir means, means for selectively controlling the rate of discharge of additive material by said vane means, additive material conduit means for conveying additive material, discharged by said second vane means, to said mixing reservoir means, and third, return branch conduit means connected with said first discharge conduit means, and second jet-defining means operable to constrain mud flowing through said third return branch conduit means into a jet stream operable to impel additive material through said additive material conduit means; and selectively operable actuating means for alternately actuating said first and second mixing means.

Claim 10

An apparatus for mixing mud for use in well-drilling operations, said apparatus comprising: mixing reservoir means; first discharge conduit means extending from said mixing reservoir means; pump means operable to convey mud through said first discharge conduit means; density-measuring means connected with said first discharge conduit means and operable to measure the density of mud flowing therethrough; return conduit means included in said first discharge conduit means and operable to return a portion of mud flow, downstream of said density-measuring means, from said first discharge conduit means to said mixing reservoir means; solid material supply means including air pressure containing, and enclosure-defining wall means operable to support a mass of pulverulent material, means for supplying pressurized air to the interior of said enclosure defining wall means, with said wall means being operable to maintain superambient pressure within said wall means, and second, discharge conduit means operable to disCharge pressurized air and pulverulent material from said supply means; first, relatively low-capacity, mixing means for supplying pulverulent material to said mixing reservoir means, said first mixing means including transfer reservoir means, first branch conduit means for conveying pressurized air and pulverulent material from said second discharge conduit means of said solid material supply means into said transfer reservoir means, first vane means defining a series of mutually isolated, rotatable pockets for discharging pulverulent material from said transfer reservoir means to said mixing reservoir means, said first vane means defining a seal between the interior of said transfer reservoir means and said mixing reservoir means, first means responsive to said density-measuring means for controlling the rate of discharge of pulverulent material from said transfer reservoir means by said first vane means, control means for controlling said conveying of pressurized air and pulverulent material through said first branch conduit means to said transfer reservoir means so as to regulate the amount of pulverulent material in said transfer reservoir means, first return branch conduit means communicating with said return conduit means, comingling means for comingling pulverulent material discharged by said first vane means and mud passing through said first return branch conduit means, said comingling means including first jet-defining means operable to form mud flowing through said return conduit means into a jet stream operable to impel pulverulent material discharged by said first vane means; second, relatively high-capacity, mixing means for supplying pulverulent material to said mixing reservoir means, said second mixing means including second branch conduit means communicating with said second discharge conduit means of said solid material supply means, said second branch conduit means bypassing said transfer reservoir means, valve means, operable in response to said density-measuring means, to control a flow of pressurized air and pulverulent material through said second branch conduit means, outlet means for discharging pressurized air and pulverulent material from said second branch conduit means toward said mixing reservoir means, second return branch conduit means communicating with said return conduit means, annular stream-defining means communicating with said second return branch conduit means and operable to define an annular flow of mud encircling pressurized air and pulverulent material discharging from said outlet means; additive supplying means including additive material reservoir means, second vane means operable to define a series of mutually isolated rotatable pockets for discharging segregated quantities of additive material from said additive material reservoir means, means for selectively controlling the rate of discharge of additive material by said vane means, additive material conduit means for conveying additive material, discharged by said second vane means, to said mixing reservoir means, and third, return branch conduit means connected with said first discharge conduit means, and second jet-defining means operable to constrain mud flowing through said third return branch conduit means into a jet stream operable to impel additive material through said additive material conduit means; and selectively operable actuating means for alternately actuating said first and second mixing means.

Claim 11

An apparatus for mixing mud for use in well-drilling operations, said apparatus comprising: mixing reservoir means; first discharge conduit means extending from said mixing reservoir means; pump means operable to convey mud through said first discharge conduit means; density-measuring means connected with said first discharge conduit means and operable to measure the density of mud flowing therethrough; said densiTy-measuring means including a source of photons having a photon energy of between about 0.6 and about 2 Mev. positioned adjacent a vertical flow of said mud, means for collimating the emission of photons from said source en route to said mud, shielding means for substantially blocking the passage of photons issuing from said mud which have a photon energy level of less than about 0.3 Mev. and attenuating the passage of photons issuing from said mud having a photon energy level of less than about 0.45 Mev. by at least twice the degree of attenuation of photons issuing from said mud which have a photon energy level of about 0.6 Mev. or greater, scintillation counting means, means for impinging photons which have been subjected to said blocking and attenuating on said scintillation counting means, and means maintaining a lower discrimination level of said scintillation counting means at least as low as about 0.05 Mev.; return conduit means included in said first discharge conduit means and operable to return a portion of mud flow, downstream of said density-measuring means, from said first discharge conduit means to said mixing reservoir means; solid material supply means including air pressure containing, and enclosure-defining wall means operable to support a mass of pulverulent material, means for supplying pressurized air to the interior of said enclosure-defining wall means, with said wall means being operable to maintain superambient pressure within said wall means, and second, discharge conduit means operable to discharge pressurized air and pulverulent material from said supply means; said solid material supply means further including a first source of pulverulent, barite-containing material, a second source of pulverulent, additive material, and means for selectively blending materials from said first and second sources for passage through said second discharge conduit means; first, relatively low-capacity, mixing means for supplying pulverulent material to said mixing reservoir means, said first mixing means including transfer reservoir means, first branch conduit means for conveying pressurized air and pulverulent material from said second discharge conduit means of said solid material supply means into said transfer reservoir means, first vane means defining a series of mutually isolated rotatable pockets for discharging pulverulent material from said transfer reservoir means to said mixing reservoir means, said first vane means defining a seal between the interior of said transfer reservoir means and said mixing reservoir means, first means responsive to said density-measuring means for controlling the rate of discharge of pulverulent material from said transfer reservoir means by said first vane means, control means for controlling said conveying of pressurized air and pulverulent material through said first branch conduit means to said transfer reservoir means so as to regulate the amount of pulverulent material in said transfer reservoir means, first return branch conduit means communicating with said return conduit means, comingling means for comingling pulverulent material discharged by said first vane means and mud passing through said first return branch conduit means, said comingling means including first jet-defining means operable to form mud flowing through said return conduit means into a jet stream operable to impel pulverulent material discharged by said first vane means; second relatively high-capacity, mixing means for supplying pulverulent material to said mixing reservoir means, said second mixing means including second branch conduit means communicating with said second discharge conduit means of said solid material supply means, said second branch conduit means bypassing said transfer reservoir means, valve means, operable in response to said density-measuring mEans, to control a flow of pressurized air and pulverulent material through said second branch conduit means, said valve means including weir means extending partially transversely across said second discharge conduit means, diaphragm means operable to move transversely through the interior of said second discharge conduit means, generally toward and away from said weir means, and diaphragm moving means operable in response to said density-measuring means, outlet means for discharging pressurized air and pulverulent material from said second branch conduit means toward said mixing reservoir means, second return branch conduit means communicating with said return conduit means, annular stream-defining means communicating with said second return branch conduit means and operable to define an annular flow of mud encircling pressurized air and pulverulent material discharging from said outlet means; additive-supplying means including additive material reservoir means, second vane means operable to define a series of mutually isolated rotatable pockets for discharging segregated quantities of additive material from said additive material reservoir means, means for selectively controlling the rate of discharge of additive material by said vane means, additive material conduit means for conveying additive material discharged by said second vane means to said mixing reservoir means, and third, return branch conduit means connected with said first discharge conduit means, and second jet-defining means operable to constrain mud flowing through said third return branch conduit means into a jet stream operable to impel additive material through said additive material conduit means; and selectively operable actuating means for alternately actuating said first and second mixing means.

Claim 12

An apparatus for mixing mud for use in well-drilling operations, said apparatus comprising: mixing reservoir means; first discharge conduit means extending from said mixing reservoir means; pump means operable to convey mud through said first discharge conduit means; density-measuring means connected with said first discharge conduit means and operable to measure the density of mud flowing therethrough; said densiTy-measuring means including a source of photons having a photon energy of between about 0.6 and about 2 Mev. positioned adjacent a vertical flow of said mud, means for collimating the emission of photons from said source en route to said mud, shielding means for substantially blocking the passage of photons issuing from said mud which have a photon energy level of less than about 0.3 Mev. and attenuating the passage of photons issuing from said mud having a photon energy level of less than about 0.45 Mev. by at least twice the degree of attenuation of photons issuing from said mud which have a photon energy level of about 0.6 Mev. or greater, scintillation counting means, means for impinging photons which have been subjected to said blocking and attenuating on said scintillation counting means, and means maintaining a lower discrimination level of said scintillation counting means at least as low as about 0.05 Mev.; return conduit means included in said first discharge conduit means and operable to return a portion of mud flow, downstream of said density-measuring means, from said first discharge conduit means to said mixing reservoir means; solid material supply means including air pressure containing, and enclosure-defining wall means operable to support a mass of pulverulent material, means for supplying pressurized air to the interior of said enclosure-defining wall means, with said wall means being operable to maintain superambient pressure within said wall means, and second, discharge conduit means operable to discharge pressurized air and pulverulent material from said supply means; said solid material supply means further including a first source of pulverulent, barite-containing material, a second source of pulverulent, additive material, and means for selectively blending materials from said first and second sources for passage through said second discharge conduit means; first, relatively low-capacity, mixing means for supplying pulverulent material to said mixing reservoir means, said first mixing means including transfer reservoir means, first branch conduit means for conveying pressurized air and pulverulent material from said second discharge conduit means of said solid material supply means into said transfer reservoir means, first vane means defining a series of mutually isolated rotatable pockets for discharging pulverulent material from said transfer reservoir means to said mixing reservoir means, said first vane means defining a seal between the interior of said transfer reservoir means and said mixing reservoir means, first means responsive to said density-measuring means for controlling the rate of discharge of pulverulent material from said transfer reservoir means by said first vane means, control means for controlling said conveying of pressurized air and pulverulent material through said first branch conduit means to said transfer reservoir means so as to regulate the amount of pulverulent material in said transfer reservoir means, first return branch conduit means communicating with said return conduit means, comingling means for comingling pulverulent material discharged by said first vane means and mud passing through said first return branch conduit means, said comingling means including first jet-defining means operable to form mud flowing through said return conduit means into a jet stream operable to impel pulverulent material discharged by said first vane means; second relatively high-capacity, mixing means for supplying pulverulent material to said mixing reservoir means, said second mixing means including second branch conduit means communicating with said second discharge conduit means of said solid material supply means, said second branch conduit means bypassing said transfer reservoir means, valve means, operable in response to said density-measuring mEans, to control a flow of pressurized air and pulverulent material through said second branch conduit means, said valve means including weir means extending partially transversely across said second discharge conduit means, diaphragm means operable to move transversely through the interior of said second discharge conduit means, generally toward and away from said weir means, and diaphragm moving means operable in response to said density-measuring means, outlet means for discharging pressurized air and pulverulent material from said second branch conduit means toward said mixing reservoir means, second return branch conduit means communicating with said return conduit means, annular stream-defining means communicating with said second return branch conduit means and operable to define an annular flow of mud encircling pressurized air and pulverulent material discharging from said outlet means; additive-supplying means including additive material reservoir means, second vane means operable to define a series of mutually isolated rotatable pockets for discharging segregated quantities of additive material from said additive material reservoir means, means for selectively controlling the rate of discharge of additive material by said vane means, additive material conduit means for conveying additive material discharged by said second vane means to said mixing reservoir means, and third, return branch conduit means connected with said first discharge conduit means, and second jet-defining means operable to constrain mud flowing through said third return branch conduit means into a jet stream operable to impel additive material through said additive material conduit means; and selectively operable actuating means for alternately actuating said first and second mixing means.

Claim 13

A method for mixing material, said method comprising: supplying a high-density material from first supply means, at a relatively low rate, to reservoir means; supplying high-density material from second supply means to said reservoir means at a relatively high rate; measuring the density of mixed material in said reservoir means, said measuring being effected with radioactive density-measuring means, having a source of photons with a photon energy level of between about 0.6 and about 2 Mev.; regulating an alternate flow of material through said first and second supply means in response to said measuring, while maintaining a substantially constant calibration of said radioactive density-measuring means.

Claim 14

A method for mixing material, said method comprising: supplying a high-density material from first supply means, at a relatively low rate, to reservoir means; supplying high-density material from second supply means to said reservoir means at a relatively high rate; measuring the density of mixed material in said reservoir means, said measuring being effected with radioactive density-measuring means, having a source of photons with a photon energy level of between about 0.6 and about 2 Mev.; regulating an alternate flow of material through said first and second supply means in response to said measuring, while maintaining a substantially constant calibration of said radioactive density-measuring means.

Claim 15

A method for mixing mud to be used in well-drilling operations, said method comprising: supplying a pulverulent barite-containing material from first supply means, at a relatively low rate, to mud-mixing reservoir means; supplying pulverulent, barite-containing material from second supply means to said mixing reservoir means at a relatively high rate; measuring the density of mud in said mixing reservoir means, said measuring being effected by positioning a source of photons having a photon energy of between about 0.6 and about 2 Mev. adjacent a vertical flow of said mud, substantially blocking the passage of photons issuing from said mud which have a photon energy level of less than about 0.3 Mev., and attenuating the passage of photons issuing from said mud having a photon energy level of less than about 0.45 Mev. by at least twice the degree of attenuation of photons issuing from said mud which have a photon energy level of about 0.6 Mev. or greater, and impinging photons which have been subjected to said blocking and attenuating on photon-counting means; and alternately regulating the flow of pulverulent material through said first and second supply means in response to said measuring.

Claim 16

A method for mixing mud to be used in well-drilling operations, said method comprising: supplying a pulverulent barite-containing material from first supply means, at a relatively low rate, to mud-mixing reservoir means; supplying pulverulent, barite-containing material from second supply means to said mixing reservoir means at a relatively high rate; measuring the density of mud in said mixing reservoir means, said measuring being effected by positioning a source of photons having a photon energy of between about 0.6 and about 2 Mev. adjacent a vertical flow of said mud, substantially blocking the passage of photons issuing from said mud which have a photon energy level of less than about 0.3 Mev., and attenuating the passage of photons issuing from said mud having a photon energy level of less than about 0.45 Mev. by at least twice the degree of attenuation of photons issuing from said mud which have a photon energy level of about 0.6 Mev. or greater, and impinging photons which have been subjected to said blocking and attenuating on photon-counting means; and alternately regulating the flow of pulverulent material through said first and second supply means in response to said measuring.

Claim 17

A method for mixing mud to be used in well-drilling operations, said method comprising: supplying a puLverulent barite-containing material from first supply means, at a relatively low rate, to mud-mixing reservoir means; supplying pulverulent, barite-containing material from second supply means to said mixing reservoir means at a relatively high rate; measuring the density of mud in said mixing reservoir means, said measuring being effective by positioning a source of photons having a photon energy of between about 0.6 and about 2 Mev. adjacent a vertical flow of said mud, collimating the emission of photons from said source en route to said mud, substantially blocking the passage of photons issuing from said mud which have a photon energy level of less than about 0.3 Mev., attenuating the passage of photons issuing from said mud having a photon energy level of less than about 0.45 Mev. by at least twice the degree of attenuation of photons issuing from said mud, which have a photon energy level of about 0.6 Mev. or greater, impinging photons which have been subjected to said blocking and attenuating on scintillation counting means, and maintaining a lower discrimination level of said scintillation counting means at least as low as about 0.05 Mev.; alternately regulating the flow of pulverulent material through said first and second supply means in response to said measuring; and pneumatically impelling said material through each of said first and second supply means.

Claim 18

A method for mixing mud to be used in well-drilling operations, said method comprising: supplying a puLverulent barite-containing material from first supply means, at a relatively low rate, to mud-mixing reservoir means; supplying pulverulent, barite-containing material from second supply means to said mixing reservoir means at a relatively high rate; measuring the density of mud in said mixing reservoir means, said measuring being effective by positioning a source of photons having a photon energy of between about 0.6 and about 2 Mev. adjacent a vertical flow of said mud, collimating the emission of photons from said source en route to said mud, substantially blocking the passage of photons issuing from said mud which have a photon energy level of less than about 0.3 Mev., attenuating the passage of photons issuing from said mud having a photon energy level of less than about 0.45 Mev. by at least twice the degree of attenuation of photons issuing from said mud, which have a photon energy level of about 0.6 Mev. or greater, impinging photons which have been subjected to said blocking and attenuating on scintillation counting means, and maintaining a lower discrimination level of said scintillation counting means at least as low as about 0.05 Mev.; alternately regulating the flow of pulverulent material through said first and second supply means in response to said measuring; and pneumatically impelling said material through each of said first and second supply means.

Claim 19

A method for mixing mud to be used in well drilling operations, said method comprising: supplying a pulverulent barite-containing material from first supply means, at a relatively low rate, to mud-mixing reservoir means; supplying pulverulent, barite-containing material from second supply means to said mixing reservoir means at a relatively high rate; measuring the density of mud in said mixing reservoir means, said measuring means being effected by positioning a Cs 137 source of photons having a photon energy of about 0.661 Mev. adjacent a vertical flow of said mud, collimating the emission of photons from said source en route to said mud, substantially blocking the passage of photons issuing from said mud which have a photon energy level of less than about 0.3 Mev., attenuating the passage of photons issuing from said mud having a photon energy level of less than about 0.45 Mev. by at least twice the degree of attenuation of photons issuing from said mud, which have a photon energy level of about 0.6 Mev. or greater, impinging photons which have been subjected to said blocking and attenuating on a thallium-activated sodium iodide crystal, and maintaining a lower discrimination level of said scintillation counting means at least as low as about 0.05 Mev.; regulating an alternate flow of pulverulent material through said first and second supply means in response to said measuring; pneumatically impelling said material through each of said first and second supply means; adding additional mud additive substances to said mixing reservoir means at a rate of addition independent of said measuring; and impelling at least a portion of said barite material with a mud jet en route to said reservoir means.

Claim 20

A method for mixing mud to be used in well drilling operations, said method comprising: supplying a pulverulent barite-containing material from first supply means, at a relatively low rate, to mud-mixing reservoir means; supplying pulverulent, barite-containing material from second supply means to said mixing reservoir means at a relatively high rate; measuring the density of mud in said mixing reservoir means, said measuring means being effected by positioning a Cs 137 source of photons having a photon energy of about 0.661 Mev. adjacent a vertical flow of said mud, collimating the emission of photons from said source en route to said mud, substantially blocking the passage of photons issuing from said mud which have a photon energy level of less than about 0.3 Mev., attenuating the passage of photons issuing from said mud having a photon energy level of less than about 0.45 Mev. by at least twice the degree of attenuation of photons issuing from said mud, which have a photon energy level of about 0.6 Mev. or greater, impinging photons which have been subjected to said blocking and attenuating on a thallium-activated sodium iodide crystal, and maintaining a lower discrimination level of said scintillation counting means at least as low as about 0.05 Mev.; regulating an alternate flow of pulverulent material through said first and second supply means in response to said measuring; pneumatically impelling said material through each of said first and second supply means; adding additional mud additive substances to said mixing reservoir means at a rate of addition independent of said measuring; and impelling at least a portion of said barite material with a mud jet en route to said reservoir means.

Claim 21

A method for mixing material, said method comprising: supplying a high-density material from first supply means, at a relatively low rate, to reservoir means; supplying high-density material from second supply means to said reservoir means at a relatively high rate; impelling at least a portion of said high-density material with a mud jet en route to said reservoir means; measuring the density of mixed material in said reservoir means, said measuring being effected with density-measuring means; regulating an alternate flow of material through said first and second supply means in response to said measuring, while maintaining a substantially constant calibration Of said density-measuring means.

Claim 22

A method for mixing material, said method comprising: supplying a high-density material from first supply means, at a relatively low rate, to reservoir means; supplying high-density material from second supply means to said reservoir means at a relatively high rate; impelling at least a portion of said high-density material with a mud jet en route to said reservoir means; measuring the density of mixed material in said reservoir means, said measuring being effected with density-measuring means; regulating an alternate flow of material through said first and second supply means in response to said measuring, while maintaining a substantially constant calibration Of said density-measuring means.

Claim 23

A method for mixing material, said method comprising: supplying a high-density material from first supply means, at a relatively low rate, to reservoir means; supplying high-density material from second supply means to said reservoir means at a relatively high rate; pneumatically impelling said high-density material through each of said first and second supply means; measuring the density of mixed material in said reservoir means, said measuring being effected with measuring means; and regulating an alternate flow of material through said first and second supply means in response to said measuring, while maintaining a substantially constant calibration of said measuring means.

Claim 24

A method for mixing material, said method comprising: supplying a high-density material from first supply means, at a relatively low rate, to reservoir means; supplying high-density material from second supply means to said reservoir means at a relatively high rate; pneumatically impelling said high-density material through each of said first and second supply means; measuring the density of mixed material in said reservoir means, said measuring being effected with measuring means; and regulating an alternate flow of material through said first and second supply means in response to said measuring, while maintaining a substantially constant calibration of said measuring means.

Claim 25

An apparatus for mixing material, said apparatus comprising: reservoir means; first supply means for supplying a high-density material, at a relatively low rate, to said reservoir means; second supply means for supplying a high-density material to said reservoir means at a relatively high rate; means for pneumatically conveying said high-density material through each of said first and second supply means; and density-measuring means operable to measure the density of material mixed in said reservoir means, said density-measuring means being operable, substantially independent of the composition of said mixed material, to indicate mixed material density, with the calibration of said measuring means being substantially the same when each of said first and second supply means is independently supplying material to said reservoir means.

Claim 26

An apparatus for mixing material, said apparatus comprising: reservoir means; first supply means for supplying a high-density material, at a relatively low rate, to said reservoir means; second supply means for supplying a high-density material to said reservoir means at a relatively high rate; means for pneumatically conveying said high-density material through each of said first and second supply means; and density-measuring means operable to measure the density of material mixed in said reservoir means, said density-measuring means being operable, substantially independent of the composition of said mixed material, to indicate mixed material density, with the calibration of said measuring means being substantially the same when each of said first and second supply means is independently supplying material to said reservoir means.

Claim 27

An apparatus for mixing material, said apparatus comprising: reservoir means; first supply means for supplying a high-density material, at a relatively low rate, to said reservoir means, said first supply means including a transfer reservoir means; second supply means for supplying a high-density material to said reservoir means at a relatively high rate; and density-measuring means operable to measure the density of material mixed in said reservoir means, said density-measuring means including density-measuring means operable, substantially independent of the composition of said mixed material, to indicate mixed material density, with the calibration of said density-measuring means being substantially the same when each of said first and second supply means is independently supplying material to said reservoir means.

Claim 28

An apparatus for mixing material, said apparatus comprising: reservoir means; first supply means for supplying a high-density material, at a relatively low rate, to said reservoir means, said first supply means including a transfer reservoir means; second supply means for supplying a high-density material to said reservoir means at a relatively high rate; and density-measuring means operable to measure the density of material mixed in said reservoir means, said density-measuring means including density-measuring means operable, substantially independent of the composition of said mixed material, to indicate mixed material density, with the calibration of said density-measuring means being substantially the same when each of said first and second supply means is independently supplying material to said reservoir means.

Claim 29

An apparatus for mixing mud for use in well-drilling operations, said apparatus comprising: mixing reservoir means; first discharge conduit means extending from said mixing reservoir means; pump means operable to convey mud through said first discharge conduit means; density-measuring means connected with said first discharge conduit means and operable to measure the density of mud flowing therethrough; return conduit means included in said first discharge conduit means and operable to return a portion of mud flow, downstream of said density-measuring means, from said first discharge conduit means to said mixing reservoir means; solid material supply means including air pressure containing, and enclosure-defining wall means operable to support a mass of pulverulent material, means for supplying pressurized air to the interior of said enclosure-defining wall means, with said wall means being operable to maintain superambient pressure within said wall means, and second, discharge conduit means operable to discharge pressurized air and pulverulent material from said supply means; and mixing means for supplying pulverulent material to said mixing reservoir means, said mixing means including transfer reservoir means, branch conduit means for conveying pressurized air and pulverulent material from said second discharge conduit means of said solid material supply means into said transfer reservoir means, material-transferring seal means defining a seal between the intErior of said transfer reservoir means and said mixing reservoir means, but operable to discharge pulverulent material to said mixing reservoir means, means responsive to said density-measuring means for controlling the rate of discharge of pulverulent material from said transfer reservoir means by said seal means, control means for controlling said conveying of pressurized air and pulverulent material through said branch conduit means to said transfer reservoir means so as to regulate the amount of pulverulent material in said transfer reservoir means, return branch conduit means communicating with said return conduit means, and comingling means for comingling pulverulent material discharged by said seal means and mud passing through said return branch conduit means, said comingling means including jet-defining means operable to form mud flowing through said return conduit means into a jet stream operable to impel pulverulent material discharged by said seal means.

Claim 30

An apparatus for mixing mud for use in well-drilling operations, said apparatus comprising: mixing reservoir means; first discharge conduit means extending from said mixing reservoir means; pump means operable to convey mud through said first discharge conduit means; density-measuring means connected with said first discharge conduit means and operable to measure the density of mud flowing therethrough; return conduit means included in said first discharge conduit means and operable to return a portion of mud flow, downstream of said density-measuring means, from said first discharge conduit means to said mixing reservoir means; solid material supply means including air pressure containing, and enclosure-defining wall means operable to support a mass of pulverulent material, means for supplying pressurized air to the interior of said enclosure-defining wall means, with said wall means being operable to maintain superambient pressure within said wall means, and second, discharge conduit means operable to discharge pressurized air and pulverulent material from said supply means; and mixing means for supplying pulverulent material to said mixing reservoir means, said mixing means including transfer reservoir means, branch conduit means for conveying pressurized air and pulverulent material from said second discharge conduit means of said solid material supply means into said transfer reservoir means, material-transferring seal means defining a seal between the intErior of said transfer reservoir means and said mixing reservoir means, but operable to discharge pulverulent material to said mixing reservoir means, means responsive to said density-measuring means for controlling the rate of discharge of pulverulent material from said transfer reservoir means by said seal means, control means for controlling said conveying of pressurized air and pulverulent material through said branch conduit means to said transfer reservoir means so as to regulate the amount of pulverulent material in said transfer reservoir means, return branch conduit means communicating with said return conduit means, and comingling means for comingling pulverulent material discharged by said seal means and mud passing through said return branch conduit means, said comingling means including jet-defining means operable to form mud flowing through said return conduit means into a jet stream operable to impel pulverulent material discharged by said seal means.

Claim 31

An apparatus for mixing mud for use in well-drilling operations, said apparatus comprising: mixing reservoir means; first discharge conduit means extending from said mixing reservoir means; pump means operable to convey mud through said first discharge conduit means; density-measuring means connected with said first discharge conduit means and operable to measure the density of mud flowing therethrough; said density-measuring means including a source of photons having a photon energy of between about 0.6 and about 2 Mev. positioned adjacent a vertical flow of said mud, means for collimating the emission of photons from said source en route to said mud, shielding means for substantially blocking the passage of photons issuing from said mud which have a photon energy level of less than abut 0.3 Mev. and attenuating the passage of photons issuing from said mud having a photon energy level of less than about 0.45 Mev. by at least twice the degree of attenuation of photons issuing from said mud which have a photon energy level of about 0.6 Mev. or greater, scintillation counting means, means for impinging photons which have been subjected to said blocking and attenuating on said scintillation counting means, and means maintaining a lower discrimination level of said scintillation counting means at least as low as about 0.05 Mev.; return conduit means included in said first discharge conduit means and operable to return a portion of mud flow, downstream of said density-measuring means, from said first discharge conduit means to said mixing reservoir means; solid material supply means including air pressure containing, and enclosure-defining wall means operable to support a mass of pulverulent material, means for supplying pressurized air to the interior of said enclosure-defining wall means, with said wall means being operable to maintain superambient pressure within said wall means, and second, discharge conduit means operable to discharge pressurized air and pulverulent material from said supply means; said solid material supply means further including a first source of pulverulent, barite-containing material, a second source of pulverulent, additive material, and means for selectively blending materials from said first and second sources for passage through said second discharge conduit means; and mixing means for supplying pulverulent material to said mixing reservoir means, said mixing means including transfer reservoir means, branch conduit means for conveying pressurized air and pulverulent material from said second discharge conduit means of said solid material supply means into said transfer reservoir means, vane means defining a series of mutually isolated rotatable pockets for discharging pulverulent material from said transfer reservoir means to said mixing reservoir means, said vane means defining a seal Between the interior of said transfer reservoir means and said mixing reservoir means, means responsive to said density-measuring means for controlling the rate of discharge of pulverulent material from said transfer reservoir means by said vane means, control means for controlling said conveying of pressurized air and pulverulent material through said branch conduit means to said transfer reservoir means so as to regulate the amount of pulverulent material in said transfer reservoir means, return branch conduit means communicating with said return conduit means, and comingling means for comingling pulverulent material discharged by said vane means and mud passing through said return branch conduit means, said comingling means including jet-defining means operable to form mud flowing through said return conduit means into a jet stream operable to impel pulverulent material discharged by said vane means.

Claim 32

An apparatus for mixing mud for use in well-drilling operations, said apparatus comprising: mixing reservoir means; first discharge conduit means extending from said mixing reservoir means; pump means operable to convey mud through said first discharge conduit means; density-measuring means connected with said first discharge conduit means and operable to measure the density of mud flowing therethrough; said density-measuring means including a source of photons having a photon energy of between about 0.6 and about 2 Mev. positioned adjacent a vertical flow of said mud, means for collimating the emission of photons from said source en route to said mud, shielding means for substantially blocking the passage of photons issuing from said mud which have a photon energy level of less than abut 0.3 Mev. and attenuating the passage of photons issuing from said mud having a photon energy level of less than about 0.45 Mev. by at least twice the degree of attenuation of photons issuing from said mud which have a photon energy level of about 0.6 Mev. or greater, scintillation counting means, means for impinging photons which have been subjected to said blocking and attenuating on said scintillation counting means, and means maintaining a lower discrimination level of said scintillation counting means at least as low as about 0.05 Mev.; return conduit means included in said first discharge conduit means and operable to return a portion of mud flow, downstream of said density-measuring means, from said first discharge conduit means to said mixing reservoir means; solid material supply means including air pressure containing, and enclosure-defining wall means operable to support a mass of pulverulent material, means for supplying pressurized air to the interior of said enclosure-defining wall means, with said wall means being operable to maintain superambient pressure within said wall means, and second, discharge conduit means operable to discharge pressurized air and pulverulent material from said supply means; said solid material supply means further including a first source of pulverulent, barite-containing material, a second source of pulverulent, additive material, and means for selectively blending materials from said first and second sources for passage through said second discharge conduit means; and mixing means for supplying pulverulent material to said mixing reservoir means, said mixing means including transfer reservoir means, branch conduit means for conveying pressurized air and pulverulent material from said second discharge conduit means of said solid material supply means into said transfer reservoir means, vane means defining a series of mutually isolated rotatable pockets for discharging pulverulent material from said transfer reservoir means to said mixing reservoir means, said vane means defining a seal Between the interior of said transfer reservoir means and said mixing reservoir means, means responsive to said density-measuring means for controlling the rate of discharge of pulverulent material from said transfer reservoir means by said vane means, control means for controlling said conveying of pressurized air and pulverulent material through said branch conduit means to said transfer reservoir means so as to regulate the amount of pulverulent material in said transfer reservoir means, return branch conduit means communicating with said return conduit means, and comingling means for comingling pulverulent material discharged by said vane means and mud passing through said return branch conduit means, said comingling means including jet-defining means operable to form mud flowing through said return conduit means into a jet stream operable to impel pulverulent material discharged by said vane means.

Claim 33

An apparatus for mixing mud for use in well-drilling operations, said apparatus comprising: mixing reservoir means; first discharge conduit means extending from said mixing reservoir means; pump means operable to convey mud through said first discharge conduit means; density-measuring means connected with said first discharge conduit means and operable to measure the density of mud flowing therethrough; return conduit means included in said first discharge conduit means and operable to return a portion of mud flow, downstream of said density-measuring means, from said first discharge conduit means to said mixing reservoir means; solid material supply means including air pressure containing, and enclosure-defining wall means operable to support a mass of pulverulent material, means for supplying pressurized air to the interior of said enclosure-defining wall means, with said wall means being operable to maintain superambient pressure within said wall means, and second, discharge conduit means operable to discharge pressurized air and pulverulent material from said supply means; and mixing means for supplying pulverulent material to said mixing reservoir means, said mixing means including branch conduit means communicating with said second discharge conduit means of said solid material supply means, said branch conduit means bypassing said transfer reservoir means, valve means, operable in response to said density-measuring means, to control a flow of pressurized air and pulverulent material through said branch conduit means, outlet means for discharging pressurized air and pulverulent material from said branch conduit means toward said mixing reservoir means, return branch conduit means communicating with said return conduit means, and annular stream-defining means communicating with said return branch conduit means and operable to define an annular flow of mud encircling pressurized air and pulverulent material discharging from said outlet means.

Claim 34

An apparatus for mixing mud for use in well-drilling operations, said apparatus comprising: mixing reservoir means; first discharge conduit means extending from said mixing reservoir means; pump means operable to convey mud through said first discharge conduit means; density-measuring means connected with said first discharge conduit means and operable to measure the density of mud flowing therethrough; return conduit means included in said first discharge conduit means and operable to return a portion of mud flow, downstream of said density-measuring means, from said first discharge conduit means to said mixing reservoir means; solid material supply means including air pressure containing, and enclosure-defining wall means operable to support a mass of pulverulent material, means for supplying pressurized air to the interior of said enclosure-defining wall means, with said wall means being operable to maintain superambient pressure within said wall means, and second, discharge conduit means operable to discharge pressurized air and pulverulent material from said supply means; and mixing means for supplying pulverulent material to said mixing reservoir means, said mixing means including branch conduit means communicating with said second discharge conduit means of said solid material supply means, said branch conduit means bypassing said transfer reservoir means, valve means, operable in response to said density-measuring means, to control a flow of pressurized air and pulverulent material through said branch conduit means, outlet means for discharging pressurized air and pulverulent material from said branch conduit means toward said mixing reservoir means, return branch conduit means communicating with said return conduit means, and annular stream-defining means communicating with said return branch conduit means and operable to define an annular flow of mud encircling pressurized air and pulverulent material discharging from said outlet means.

Claim 35

An apparatus for mixing mud for use in well-drilling operations, said apparatus comprising: mixing reservoir means; first discharge conduit means extending from said mixing reservoir means; pump means operable to convey mud through said first discharge conduit means; density-measuring means connected with said first discharge conduit means and operable to measure the density of mud flowing therethrough; said density-measuring means including a source of photons having a photon energy of between about 0.6 and about 2 Mev. positioned adjacent a vertical flow of said mud, means for collimating the emission of photons from said source en route to said mud, shielding means for substantially blocking the passage of photons issuing from said mud which have a photon energy level of less than about 0.3 Mev. and attenuating the passage of photons issuing from said mud having a photon energy level of less than about 0.45 Mev. by at least twice the degree of attenuation of photons issuing from said mud which have a photon energy level of about 0.6 Mev. or greater, scintillation counting means, means for impinging photons which have been subjected to said blocking and attenuating on said scintillation counting means, and means maintaining a lower discrimination level of said scintillation counting means at least as low as about 0.05 Mev.; return conduit means included in said first discharge conduit means and operable to return a portion of mud flow, downstream of said density-measuring means, from said first discharge conduit means to said mixing reservoir means; solid material supply means including air pressure containing, and enclosure-defining wall means operable to support a mass of pulverulent material, means for supplying pressurized air to the interior of said enclosure-defining wall means, with said wall means being operable to maintain superambient pressure within said wall means, and second, discharge conduit means operable to discharge pressurized air and pulverulent material from said supply means; said solid material supply means further including a first source of pulverulent, barite-containing material, a second source of pulverulent, additive material, and means for selectively blending materials from said first and second sources for passage through said second discharge conduit means; and mixing means for supplying pulverulent material to said mixing reservoir means, said mixing means including branch conduit means communicating with said second discharge conduit means of said solid material supply means, said branch conduit means bypassing said transfer reservoir means, valve means, operable in response to said density-measuring means, to control a flow of pressurized air and pulverulent material through said branch conduit means, said valve means including weir means extending partially transversely across said second discharge conduit means, diaphragm means operable to move transversely through the interior of said second discharge conduit means, generally toward and away from said weir means, and diaphragm moving means operable in response to said density-measuring means, outlet means for discharging pressurized air and pulverulent material from said branch conduit means toward said mixing reservoir means, return branch conduit means communicating with said return conduit means, and annular stream-defining means communicating with said return branch conduit means and operable to define an annular flow of mud encircling pressurized air and pulverulent material discharging from said outlet means.

Claim 36

An apparatus for mixing mud for use in well-drilling operations, said apparatus comprising: mixing reservoir means; first discharge conduit means extending from said mixing reservoir means; pump means operable to convey mud through said first discharge conduit means; density-measuring means connected with said first discharge conduit means and operable to measure the density of mud flowing therethrough; said density-measuring means including a source of photons having a photon energy of between about 0.6 and about 2 Mev. positioned adjacent a vertical flow of said mud, means for collimating the emission of photons from said source en route to said mud, shielding means for substantially blocking the passage of photons issuing from said mud which have a photon energy level of less than about 0.3 Mev. and attenuating the passage of photons issuing from said mud having a photon energy level of less than about 0.45 Mev. by at least twice the degree of attenuation of photons issuing from said mud which have a photon energy level of about 0.6 Mev. or greater, scintillation counting means, means for impinging photons which have been subjected to said blocking and attenuating on said scintillation counting means, and means maintaining a lower discrimination level of said scintillation counting means at least as low as about 0.05 Mev.; return conduit means included in said first discharge conduit means and operable to return a portion of mud flow, downstream of said density-measuring means, from said first discharge conduit means to said mixing reservoir means; solid material supply means including air pressure containing, and enclosure-defining wall means operable to support a mass of pulverulent material, means for supplying pressurized air to the interior of said enclosure-defining wall means, with said wall means being operable to maintain superambient pressure within said wall means, and second, discharge conduit means operable to discharge pressurized air and pulverulent material from said supply means; said solid material supply means further including a first source of pulverulent, barite-containing material, a second source of pulverulent, additive material, and means for selectively blending materials from said first and second sources for passage through said second discharge conduit means; and mixing means for supplying pulverulent material to said mixing reservoir means, said mixing means including branch conduit means communicating with said second discharge conduit means of said solid material supply means, said branch conduit means bypassing said transfer reservoir means, valve means, operable in response to said density-measuring means, to control a flow of pressurized air and pulverulent material through said branch conduit means, said valve means including weir means extending partially transversely across said second discharge conduit means, diaphragm means operable to move transversely through the interior of said second discharge conduit means, generally toward and away from said weir means, and diaphragm moving means operable in response to said density-measuring means, outlet means for discharging pressurized air and pulverulent material from said branch conduit means toward said mixing reservoir means, return branch conduit means communicating with said return conduit means, and annular stream-defining means communicating with said return branch conduit means and operable to define an annular flow of mud encircling pressurized air and pulverulent material discharging from said outlet means.

Claim 37

An apparatus for mixing material, said apparatus comprising: reservoir means; pneumatic means for conveying pneumatically impelled material toward said reservoir means; means operable to flow with said pneumatically conveyed material toward said reservoir means; means to comingle at least a portion of said material with a mud jet en route to said reservoir means; and density-measuring means operable to measure the density of material mixed in said reservoir means, said density-measuring means including radioactive density-measuring means operable, substantially independent of the composition of said mixed material, to indicate mixed material density.

Claim 38

An apparatus for mixing material, said apparatus comprising: reservoir means; pneumatic means for conveying pneumatically impelled material toward said reservoir means; means operable to flow with said pneumatically conveyed material toward said reservoir means; means to comingle at least a portion of said material with a mud jet en route to said reservoir means; and density-measuring means operable to measure the density of material mixed in said reservoir means, said density-measuring means including radioactive density-measuring means operable, substantially independent of the composition of said mixed material, to indicate mixed material density.

Claim 41

A method for mixing material, said method comprising: pneumatically impelling material toward reservoir means; conveying said pneumatically impelled material with a liquid stream toward said reservoir means; measuring the density of material mixed in said reservoir means with density-measuring means including radioactive density-measuring means operable, substantially independent of the composition of said mixed material, to indicate mixed material density; and regulating the flow of said pneumatically impelled material in response to said measuring.

Claim 42

A method for mixing material, said method comprising: pneumatically impelling material toward reservoir means; conveying said pneumatically impelled material with a liquid stream toward said reservoir means; measuring the density of material mixed in said reservoir means with density-measuring means including radioactive density-measuring means operable, substantially independent of the composition of said mixed material, to indicate mixed material density; and regulating the flow of said pneumatically impelled material in response to said measuring.

Claim 43

A method for mixing material, said method comprising: supplying pulverulent material from supply means to mixing reservoir means; measuring the density of mixed material in said mixing reservoir means, said measuring means being effected by positioning a source of photons having a photon energy of between about 0.6 and 2 Mev. adjacent a flow of said mixed material, substantially blocking the passage of photons issuing from said mixed material which have a photon energy level of less than about 0.3 Mev., attenuating the passage of photons issuing from said mixed material having a photon energy level of less than about 0.45 Mev. by at least twice the degree of attenuation of photons issuing from said mixed material, which have a photon energy level of about 0.6 Mev. or greater, and impinging photons which have been subjected to said blocking and attenuating on photon counting means; regulating a flow of pulverulent material through said supply means in response to said measuring; pneumatically impelling said pulverulent material through said supply means; and conveying at least a portion of said pulverulent material with a liquid en route to said reservoir means.

Claim 44

A method for mixing material, said method comprising: supplying pulverulent material from supply means to mixing reservoir means; measuring the density of mixed material in said mixing reservoir means, said measuring means being effected by positioning a source of photons having a photon energy of between about 0.6 and 2 Mev. adjacent a flow of said mixed material, substantially blocking the passage of photons issuing from said mixed material which have a photon energy level of less than about 0.3 Mev., attenuating the passage of photons issuing from said mixed material having a photon energy level of less than about 0.45 Mev. by at least twice the degree of attenuation of photons issuing from said mixed material, which have a photon energy level of about 0.6 Mev. or greater, and impinging photons which have been subjected to said blocking and attenuating on photon counting means; regulating a flow of pulverulent material through said supply means in response to said measuring; pneumatically impelling said pulverulent material through said supply means; and conveying at least a portion of said pulverulent material with a liquid en route to said reservoir means.