Abstract: The present invention generally relates to extrusion-resistant seals for an expandable tubular assembly. In one aspect, a seal assembly for creating a seal between a first tubular and a second tubular is provided. The seal assembly includes an annular member attached to the first tubular, the annular member having a groove formed on an outer surface of the annular member. The seal assembly further includes a seal member disposed in the groove, the seal member having one or more anti-extrusion bands. The seal member is configured to be expandable radially outward into contact with an inner wall of the second tubular by the application of an outwardly directed force supplied to an inner surface of the annular member. Additionally, the seal assembly includes a gap defined between the seal member and a side of the groove. In another aspect, a method of creating a seal between a first tubular and a second tubular is provided.

Abstract: A centralizer having bow springs in a retracted position to facilitate passage through a restriction. After passing through the restriction, the bow springs may be expanded to support a casing. In one embodiment, the bow springs may be expanded using a movable sleeve.

Abstract: The present invention generally relates to extrusion-resistant seals for an expandable tubular assembly. In one aspect, a seal assembly for creating a seal between a first tubular and a second tubular is provided. The seal assembly includes an annular member attached to the first tubular, the annular member having a groove formed on an outer surface of the annular member. The seal assembly further includes a seal member disposed in the groove, the seal member having one or more anti-extrusion bands. The seal member is configured to be expandable radially outward into contact with an inner wall of the second tubular by the application of an outwardly directed force supplied to an inner surface of the annular member. Additionally, the seal assembly includes a gap defined between the seal member and a side of the groove. In another aspect, a method of creating a seal between a first tubular and a second tubular is provided.

Abstract: A method of running casing in a dual gradient system includes lowering a casing into a low density fluid region and allowing the low density fluid to enter the casing; releasing a plug into the casing; supplying a high density fluid behind the plug; and lowering the casing into a high density fluid region until target depth is reached.

Abstract: The present invention relates methods and apparatus for lining a wellbore. In one aspect, a drilling assembly having an earth removal member and a wellbore lining conduit is manipulated to advance into the earth. The drilling assembly includes a first fluid flow path and a second fluid flow path. Fluid is flowed through the first fluid flow path, and at least a portion of which may return through the second fluid flow path. In one embodiment, the drilling assembly is provided with a third fluid flow path. After drilling has been completed, wellbore lining conduit may be cemented in the wellbore.

Abstract: The present invention generally relates to extrusion-resistant seals for an expandable tubular assembly. In one aspect, a seal assembly for creating a seal between a first tubular and a second tubular is provided. The seal assembly includes an annular member attached to the first tubular, the annular member having a groove formed on an outer surface of the annular member. The seal assembly further includes a seal member disposed in the groove, the seal member having one or more anti-extrusion bands. The seal member is configured to be expandable radially outward into contact with an inner wall of the second tubular by the application of an outwardly directed force supplied to an inner surface of the annular member. Additionally, the seal assembly includes a gap defined between the seal member and a side of the groove. In another aspect, a method of creating a seal between a first tubular and a second tubular is provided.

Abstract: The present invention generally relates to a stage tool. In one aspect, a downhole tool for use in a wellbore is provided. The tool includes a body having a bore. The tool further includes a seal assembly attached to the body. The seal assembly having an expandable annular member, a seal member and an expander sleeve, wherein the seal member includes one or more anti-extrusion spring bands embedded within the seal member. The tool further includes a slip assembly attached to the body. The slip assembly includes slips that are configured to engage the wellbore.

Abstract: A centralizer having bow springs in a retracted position to facilitate passage through a restriction. After passing through the restriction, the bow springs may be expanded to support a casing. In one embodiment, the bow springs may be expanded using a movable sleeve.

Abstract: The present invention relates methods and apparatus for lining a wellbore. In one aspect, a drilling assembly having an earth removal member and a wellbore lining conduit is manipulated to advance into the earth. The drilling assembly includes a first fluid flow path and a second fluid flow path. Fluid is flowed through the first fluid flow path, and at least a portion of which may return through the second fluid flow path. In one embodiment, the drilling assembly is provided with a third fluid flow path. After drilling has been completed, wellbore lining conduit may be cemented in the wellbore.

Abstract: A method of running casing in a dual gradient system includes lowering a casing into a low density fluid region and allowing the low density fluid to enter the casing; releasing a plug into the casing; supplying a high density fluid behind the plug; and lowering the casing into a high density fluid region until target depth is reached.

Abstract: The present invention relates methods and apparatus for lining a wellbore. In one aspect, a drilling assembly having an earth removal member and a wellbore lining conduit is manipulated to advance into the earth. The drilling assembly includes a first fluid flow path and a second fluid flow path. Fluid is flowed through the first fluid flow path, and at least a portion of which may return through the second fluid flow path. In one embodiment, the drilling assembly is provided with a third fluid flow path. After drilling has been completed, wellbore lining conduit may be cemented in the wellbore.

Abstract: The present invention relates methods and apparatus for lining a wellbore. In one aspect, a drilling assembly having an earth removal member and a wellbore lining conduit is manipulated to advance into the earth. The drilling assembly includes a first fluid flow path and a second fluid flow path. Fluid is flowed through the first fluid flow path, and at least a portion of which may return through the second fluid flow path. In one embodiment, the drilling assembly is provided with a third fluid flow path. After drilling has been completed, wellbore lining conduit may be cemented in the wellbore.

Abstract: A pressure relief valve assembly may be coupled to one or more casings and/or tubular members to control fluid communication therebetween. The valve assembly is a one-way valve assembly that relieves pressure within an annulus formed between adjacent casings and/or tubular members to prevent burst or collapse of the casings and/or tubular members. In one embodiment, the valve assembly includes a tubular body having a port for fluid communication between an exterior of the valve assembly and an interior of the valve assembly; a chamber formed in a wall of the tubular body, the chamber in fluid communication with the port; and a closure member disposed in the chamber and configured to control fluid communication through the port in response to a pressure differential.

Abstract: A method and apparatus for a pressure relief valve assembly. The valve assembly may be coupled to one or more casings and/or tubular members to control fluid communication therebetween. The valve assembly is a one-way valve assembly that relieves pressure within an annulus formed between adjacent casings and/or tubular members to prevent burst or collapse of the casings and/or tubular members. The valve assembly is resettable downhole.

Abstract: The present invention generally relates to extrusion-resistant seals for an expandable tubular assembly. In one aspect, a seal assembly for creating a seal between a first tubular and a second tubular is provided. The seal assembly includes an annular member attached to the first tubular, the annular member having a groove formed on an outer surface of the annular member. The seal assembly further includes a seal member disposed in the groove, the seal member having one or more anti-extrusion bands. The seal member is configured to be expandable radially outward into contact with an inner wall of the second tubular by the application of an outwardly directed force supplied to an inner surface of the annular member. Additionally, the seal assembly includes a gap defined between the seal member and a side of the groove. In another aspect, a method of creating a seal between a first tubular and a second tubular is provided.

Abstract: The present invention generally relates to a stage tool. In one aspect, a downhole tool for use in a wellbore is provided. The tool includes a body having a bore. The tool further includes a seal assembly attached to the body. The seal assembly having an expandable annular member, a seal member and an expander sleeve, wherein the seal member includes one or more anti-extrusion spring bands embedded within the seal member. The tool further includes a slip assembly attached to the body. The slip assembly includes slips that are configured to engage the wellbore.

Abstract: Apparatus and methods for drilling with casing. In an embodiment, methods and apparatus for deflecting casing using a diverter apparatus are disclosed. In another embodiment, the apparatus comprises a motor operating system disposed in a motor system housing, a shaft operatively connected to the motor operating system, the shaft having a passageway, and a divert assembly disposed to direct fluid flow selectively to the motor operating system and the passageway in the shaft. In another aspect, methods and apparatus for directionally drilling a casing into the formation are disclosed. Methods and apparatus for measuring the trajectory of a wellbore while directionally drilling a casing into the formation are also described.

Abstract: The present invention relates methods and apparatus for lining a wellbore. In one aspect, a drilling assembly having an earth removal member and a wellbore lining conduit is manipulated to advance into the earth. The drilling assembly includes a first fluid flow path and a second fluid flow path. Fluid is flowed through the first fluid flow path, and at least a portion of which may return through the second fluid flow path. In one embodiment, the drilling assembly is provided with a third fluid flow path. After drilling has been completed, wellbore lining conduit may be cemented in the wellbore.

Abstract: Apparatus and methods for drilling with casing. In an embodiment, methods and apparatus for deflecting casing using a diverter apparatus are disclosed. In another embodiment, the apparatus comprises a motor operating system disposed in a motor system housing, a shaft operatively connected to the motor operating system, the shaft having a passageway, and a divert assembly disposed to direct fluid flow selectively to the motor operating system and the passageway in the shaft. In another aspect, methods and apparatus for directionally drilling a casing into the formation are disclosed. Methods and apparatus for measuring the trajectory of a wellbore while directionally drilling a casing into the formation are also described.

Abstract: The present invention relates methods and apparatus for lining a wellbore. In one aspect, a drilling assembly having an earth removal member and a wellbore lining conduit is manipulated to advance into the earth. The drilling assembly includes a first fluid flow path and a second fluid flow path. Fluid is flowed through the first fluid flow path, and at least a portion of which may return through the second fluid flow path. In one embodiment, the drilling assembly is provided with a third fluid flow path. After drilling has been completed, wellbore lining conduit may be cemented in the wellbore.