Reverse circulating sub for fluid flow systems

Claim 2

A reverse circulation device for use in a bore having a hollow string therein, there being a carrier fluid supply space between the wall of the bore and the string, wherein the improvement comprises: a sub having top end means for connection with the string, a fluid motor with an upper inlet conduit connected to the bottom end of the sub, the sub having a carrier fluid supply conduit with an upper end inlet in flow communication with said carrier fluid supply space between the bore and the string and having an outlet in flow communication with the upper inlet conduit of the fluid motor, the fluid motor being of a size to lie spaced from the wall of the bore to provide a return space for the carrier fluid laden with material to be removed from a drill bit mounted at the end of the fluid motor, said sub having a laden carrier fluid return conduit with an inlet in flow communication with the laden carrier fluid return space and having an outlet at its upper end in flow communication with the hollow string to provide for removal of the laden carrier fluid from the hole.

Claim 3

The structure in claim 1, and said string comprising flexible tubing string, and a packer cup secured about said sub between the upper carrier fluid inlet and lower laden carrier fluid inlet and flaring upwardly and flaring upwardly and outwardly to engage the wall of said bore, the flare of said cup providing an upwardly open space between the cup and the sub to provide downwardly transmitted thrust from carrier fluid above the packer cup to the cup and the sub, and through the sub and its connection with the flexible tubing string, a downward pull on said string to prevent the latter from buckling in the bore and producing wear.

Claim 4

The structure in claim 1, and the carrier fluid supply conduit having a greater cross sectional flow capacity than that of the return space, whereby the rate of flow of return fluid is greater than the rate of flow of fluid in the supply conduit.

Claim 5

The structure in claim 1, and means on said sub between its upper end inlet and its laden carrier fluid return inlet and extending to said bore and separating the carrier fluid supply and return spaces in said casing.

Claim 6

The structure in claim 4, and said means for separating the carrier fluid supply and return spaces comprising a packer cup flared upwardly and outwardly to seal against the wall of the bore under pressure of carrier fluid in the casing space above the packer cup.

Claim 7

The structure in claim 4, and said means for separating the carrier fluid supply and return spaces comprising a packer cup lying about said sub and flared to seal against the wall of the bore, a sleeve slidably fitting about said sub and having its lower end engaging the bottom of the packer cup in thrust transmitting relationship thereto, a releasable retainer on said sub above said sleeve, the cup, sleeve and retainer, when the retainer is released, being slidable upwardly over the upper carrier fluid inlet and upper end of said sub when the sub is disconnected from the string.

Claim 8

A reverse circulating device for use with a down hole motor in a bore with a string of pipe, the latter defining part of a flow conduit to the bottom of the string, wherein the improvement comprises: a sub having first and second ends connected respectively to the string of pipe and to said down hole motor, the string of pipe and sub having a space between them and the inside of the bore, said sub having a carrier fluid supply conduit therein with an inlet communicating with said space below the upper end of the sub and with an outlet in its lower end having flow communication in said flow conduit from the first to the second end, the outlet being flow connected to said down hole motor, said sub having a laden carrier fluid return conduit with a return flow inlet arranged for communication with said space and a return flow outlet arranged for comMunication with the string flow conduit above said sub, and a packer cup mounted on said sub below the supply inlet and above the return flow inlet of said sub, said cup being flared upwardly and outwardly into sealing engagement with the inside wall of said bore to transmit downward pressure of carrier fluid in the bore via the cup to said sub and the down hole motor to which the sub is connected.

Claim 9

A reverse circulating device for use with a down hole motor in a bore with a string of pipe, the latter defining part of a flow conduit to the bottom of the string, wherein the improvement comprises: a sub having first and second ends connected respectively to the string of pipe and to said down hole motor, the string of pipe and sub having a space between them and the inside of the bore, said sub having a carrier fluid supply conduit therein with an inlet communicating with said space below the upper end of the sub and with an outlet in its lower end having flow communication in said flow conduit from the first to the second end, the outlet being flow connected to said down hole motor, said sub having a laden carrier fluid return conduit with a return flow inlet arranged for communication with said space and a return flow outlet arranged for comMunication with the string flow conduit above said sub, and a packer cup mounted on said sub below the supply inlet and above the return flow inlet of said sub, said cup being flared upwardly and outwardly into sealing engagement with the inside wall of said bore to transmit downward pressure of carrier fluid in the bore via the cup to said sub and the down hole motor to which the sub is connected.

Claim 10

A reverse circulation device for use in a bore hole casing having a hollow drill string therein with a down hole fluid motor, there being a drilling mud supply space between the casing and the drill string, wherein the improvement comprises: a sub having top end means for connection with the drill string, a fluid motor with an upper inlet conduit connected to the bottom end of the sub, the sub having a drilling mud supply conduit with an upper end inlet in flow communication with said drilling mud supply space between the casing and the drill string and having an outlet in flow communication with the upper inlet conduit of the fluid motor, the fluid motor being spaced from said casing to provide a mud and cuttings return space from a drill bit mounted below the fluid motor, said sub having a mud and cuttings return conduit with an inlet in flow communication with the mud and cuttings return space and having an outlet at its upper end in flow communication with the hollow drill string to provide for removal of said mud and cuttings from the hole.

Claim 11

A reverse circulation device for use in a bore hole casing having a hollow drill string therein with a down hole fluid motor, there being a drilling mud supply space between the casing and the drill string, wherein the improvement comprises: a sub having top end means for connection with the drill string, a fluid motor with an upper inlet conduit connected to the bottom end of the sub, the sub having a drilling mud supply conduit with an upper end inlet in flow communication with said drilling mud supply space between the casing and the drill string and having an outlet in flow communication with the upper inlet conduit of the fluid motor, the fluid motor being spaced from said casing to provide a mud and cuttings return space from a drill bit mounted below the fluid motor, said sub having a mud and cuttings return conduit with an inlet in flow communication with the mud and cuttings return space and having an outlet at its upper end in flow communication with the hollow drill string to provide for removal of said mud and cuttings from the hole.

Claim 12

A reverse circulating device for use in a casing with a drill string, the latter defining part of a flow conduit to a down hole motor and a drill bit at the bottom of the string, wherein the improvement comprises: a drill string of pipe, a down hole motor, a drill bit drivingly connected thereto, a sub having upper and lower ends connected in the string of drill pipe in said casing and to the upper end of the down hole motor, the drill string and sub having a space between them and the inside of the casing, said sub having a drilling mud supply conduit therein with an inlet communicating with said space below the upper end of the sub and with an outlet in its lower end arranged for flow communication with said flow conduit downwardly toward a drill bit, said sub having a drilling mud return conduit with a return flow inlet arranged for communication with said space and a return flow outlet arranged for communication with said space and a return flow outlet arranged for communication with the drill string flow conduit above said sub, and a packer cup mounted on said sub below the supply inlet and above the return flow inlet of said sub, said cup being flared only upwardly and outwardly into sealing engagement with the inside wall of said casing to transmit downward pressure of drilling mud in the casing via the cup to said sub the drill string and the drill to which the sub is connected.

Claim 13

A reverse circulating device for use in a casing with a drill string, the latter defining part of a flow conduit to a down hole motor and a drill bit at the bottom of the string, wherein the improvement comprises: a drill string of pipe, a down hole motor, a drill bit drivingly connected thereto, a sub having upper and lower ends connected in the string of drill pipe in said casing and to the upper end of the down hole motor, the drill string and sub having a space between them and the inside of the casing, said sub having a drilling mud supply conduit therein with an inlet communicating with said space below the upper end of the sub and with an outlet in its lower end arranged for flow communication with said flow conduit downwardly toward a drill bit, said sub having a drilling mud return conduit with a return flow inlet arranged for communication with said space and a return flow outlet arranged for communication with said space and a return flow outlet arranged for communication with the drill string flow conduit above said sub, and a packer cup mounted on said sub below the supply inlet and above the return flow inlet of said sub, said cup being flared only upwardly and outwardly into sealing engagement with the inside wall of said casing to transmit downward pressure of drilling mud in the casing via the cup to said sub the drill string and the drill to which the sub is connected.