Apparatus for automatically controlling the killing of oil and gas wells

Claim 2

In a well mud circulating system including a drill s stem discharging mud into a well bore, a blowout preventer device located near the upper end of said well bore, a mud return line extending from the well bore above said blowout preventer to a mud pit and a mud delivery line extending from the mud pit to the drill stem, apparatus for maintaining balanced mud circulation in said system to prevent blowout of the well by pressure of extraneous fluids in the well bore, said apparatus comprising: a. a secondary mud return line located beneath the blowout preventer device, said secondary line having a flow meter and an adjustable choke therein; b. a flow meter in said delivery line; c. means for monitoring the weight of mud being pumped into the hole; d. means for monitoring the mud pressure in both the mud delivery line and in said secondary return line; and e. computer means connected to and responsive to said flow meters, said means for monitoring the weight of mud, said adjustable choke, and said pressure monitoring means for maintaining balanced mud circulation by adjustment of said choke to vary flow through said secondary mud return line.

Claim 3

The system according to claim 1 comprising in addition thereto, means for automatically calculating the mud weight required to kill the kick.

Claim 4

The system according to claim 1, comprising in addition thereto, means to automatically increase the weight of the circulating mud, responsive to said computer means.

Claim 5

In a well mud circulating system including a drill stem discharging mud into a well bore, a blowout preventer device located near the upper end of said well bore and a mud delivery line extending from a mud pit to the drill stem, apparatus to prevent blowout of the well By pressure of extraneous fluids in the well bore, said apparatus comprising: a. a mud return line extending from the well bore to the mud pit, said return line being located beneath the blowout of the well by pressure of extraneous fluids in the well bore, said apparatus comprising: preventer and having an adjustable choke therein; b. means for monitoring the flow of the circulating mud including a first flow meter in said mud delivery line and a second flow meter in said return line; c. means for monitoring the weight of the mud being pumped into the hole; d. means for monitoring the mud pressure in both the mud delivery line and in said return line; e. computer means connected to said first flow meter, second flow meter, means for monitoring the weight of mud, adjustable choke, and pressure monitoring means to generate an alarm signal when the flow out of the secondary flowline exceeds the flow in said delivery line by a predetermined amount and to prevent blowout by adjustment of said choke thereby varying flow through said return line; and f. alarm means responsive to said alarm signal.

Claim 6

In a well mud circulating system including a drill stem discharging mud into a well bore, a blowout preventer device located near the upper end of said well bore and a mud delivery line extending from a mud pit to the drill stem, apparatus to prevent blowout of the well By pressure of extraneous fluids in the well bore, said apparatus comprising: a. a mud return line extending from the well bore to the mud pit, said return line being located beneath the blowout of the well by pressure of extraneous fluids in the well bore, said apparatus comprising: preventer and having an adjustable choke therein; b. means for monitoring the flow of the circulating mud including a first flow meter in said mud delivery line and a second flow meter in said return line; c. means for monitoring the weight of the mud being pumped into the hole; d. means for monitoring the mud pressure in both the mud delivery line and in said return line; e. computer means connected to said first flow meter, second flow meter, means for monitoring the weight of mud, adjustable choke, and pressure monitoring means to generate an alarm signal when the flow out of the secondary flowline exceeds the flow in said delivery line by a predetermined amount and to prevent blowout by adjustment of said choke thereby varying flow through said return line; and f. alarm means responsive to said alarm signal.

Claim 7

The system according to claim 4 comprising in addition thereto, means for automatically calculating the mud weight required to kill the kick.

Claim 8

The system according to claim 4, comprising in addition thereto, means to automatically increase the weight of the circulating mud, responsive to said computer means.

Claim 9

In a well mud circulating system including a drill stem discharging mud into a well bore, a blowout preventer device, located near the upper end of said well bore, a mud return line extending from the well bore above said blowout preventer device to a mud pit and a mud delivery line extending from the mud pit to the drill stem, apparatus for maintaining balanced mud circulating in said system to prevent blowout of the well by pressure of extraneous fluids in the well bore, said apparatus comprising: a. a first mud flow meter in said mud delivery line; b. a second mud flow meter in said mud return line; c. means to compare the flow rates in said first and second meters; d. means to close said blowout preventer device, responsive to a predetermined difference between said flow rates; e. a secondary mud return line located beneath the blowout preventer device, said secondary line having a flow meter and an adjustable choke therein; f. means for monitoring the volume of the circulating mud; g. means for monitoring the weight of the mud being pumped into the hole; h. means for monitoring the mud pressure in both the mud delivery line and in said secondary return line; and i. computer means utilizing said volume monitoring means and said pressure monitoring means by comparing the volumes and pressures monitored by said volume monitoring means and said pressure monitoring means, to control said adjustable choke so as to vary flow in said secondary return line, thereby equalizing the flow of mud into and out of said well.

Claim 10

In a well mud circulating system including a drill stem discharging mud into a well bore, a blowout preventer device, located near the upper end of said well bore, a mud return line extending from the well bore above said blowout preventer device to a mud pit and a mud delivery line extending from the mud pit to the drill stem, apparatus for maintaining balanced mud circulating in said system to prevent blowout of the well by pressure of extraneous fluids in the well bore, said apparatus comprising: a. a first mud flow meter in said mud delivery line; b. a second mud flow meter in said mud return line; c. means to compare the flow rates in said first and second meters; d. means to close said blowout preventer device, responsive to a predetermined difference between said flow rates; e. a secondary mud return line located beneath the blowout preventer device, said secondary line having a flow meter and an adjustable choke therein; f. means for monitoring the volume of the circulating mud; g. means for monitoring the weight of the mud being pumped into the hole; h. means for monitoring the mud pressure in both the mud delivery line and in said secondary return line; and i. computer means utilizing said volume monitoring means and said pressure monitoring means by comparing the volumes and pressures monitored by said volume monitoring means and said pressure monitoring means, to control said adjustable choke so as to vary flow in said secondary return line, thereby equalizing the flow of mud into and out of said well.

Claim 11

The system according to claim 7 comprising in addition thereto, means for automatically calculating the mud weight required to kill the kick.

Claim 12

The system according to claim 7 comprising in addition thereto, means to automatically increase the weight of the circulating mud, responsive to said computer means.