Abstract: A shifting sleeve has differential piston areas so that applied pressure displaces the sleeve against spring bias, which preferably is a series of Belleville washer stacks associated with modular mandrel components, to obtain the desired opposing force to the movement initiated with pressure applied to differential piston areas. An indexing feature is located between the sleeve and the mandrel passage wall and on a predetermined number of cycles disables the Belleville washer stacks from biasing the sleeve in an opposed direction as when pressure is applied. At this time the pressure in the mandrel acting on the differential piston area simply shifts the sleeve to open a lateral port so that fracturing through the cement that was earlier placed with the port closed can take place.

Abstract: A composite plug that can be used in fracturing has backup rings for the seal that are preferably made of a composite material. The backup rings are essentially connected segments that allow the connections to break when the plug is set and the cones are brought closer together. When the rings break to form gaps between segments in a specific ring, the adjacent ring has offset gaps so that as a whole there are no extrusion gaps that would allow the seal element to pass. The rings can be rotationally locked to each other initially at the adjacent segments that are formed when the plug is set to maintain their relative positions so that gaps between segments adjacent the seal are overlapped with segments from the adjacent ring. The segmenting backup rings can be used on one or on both sides of a sealing element.

Abstract: A shifting sleeve has differential piston areas so that applied pressure displaces the sleeve against spring bias, which preferably is a series of Belleville washer stacks associated with modular mandrel components, to obtain the desired opposing force to the movement initiated with pressure applied to differential piston areas. An indexing feature is located between the sleeve and the mandrel passage wall and on a predetermined number of cycles disables the Belleville washer stacks from biasing the sleeve in an opposed direction as when pressure is applied. At this time the pressure in the mandrel acting on the differential piston area simply shifts the sleeve to open a lateral port so that fracturing through the cement that was earlier placed with the port closed can take place.

Abstract: A shifting sleeve has differential piston areas so that applied pressure displaces the sleeve against spring bias, which preferably is a series of Belleville washer stacks associated with modular mandrel components, to obtain the desired opposing force to the movement initiated with pressure applied to differential piston areas. An indexing feature is located between the sleeve and the mandrel passage wall and on a predetermined number of cycles disables the Belleville washer stacks from biasing the sleeve in an opposed direction as when pressure is applied. At this time the pressure in the mandrel acting on the differential piston area simply shifts the sleeve to open a lateral port so that fracturing through the cement that was earlier placed with the port closed can take place.

Abstract: A composite plug that can be used in fracturing has backup rings for the seal that are preferably made of a composite material. The backup rings are essentially connected segments that allow the connections to break when the plug is set and the cones are brought closer together. When the rings break to form gaps between segments in a specific ring, the adjacent ring has offset gaps so that as a whole there are no extrusion gaps that would allow the seal element to pass. The rings can be rotationally locked to each other initially at the adjacent segments that are formed when the plug is set to maintain their relative positions so that gaps between segments adjacent the seal are overlapped with segments from the adjacent ring. The segmenting backup rings can be used on one or on both sides of a sealing element.

Abstract: A shifting tool for sleeves is supported on wireline or slickline and is pumped to the desired location by pressure from above delivered against the tool and passing around its periphery or against an articulated peripheral extending member that can optionally seal. Once in the vicinity of the desired sleeve to be shifted the shifting key is engaged to the sleeve and further applied pressure on the articulated peripheral seal shifts the sleeve in a downhole direction. The sleeve can also be shifted in an uphole direction with an anchor that grabs near the sleeve and a latch key that grabs the sleeve and is configured to retain grip as a motor moves the latch key uphole. Power can come from a wireline or can be locally provided if using slickline. The seal or extending member is retractable for tool removal or relocation.

Abstract: Methods for preparing a wellbore casing for stimulation operations comprise the steps of cementing a wellbore casing in a wellbore, the wellbore casing having a downhole tool comprising a valve and an apparatus for restricting fluid flow through the valve, such as a ball seat, disposed above the valve. Actuation of the valve opens the valve to establish fluid communication between the wellbore casing and the formation. A plug element is disposed on a seat of the ball seat and a casing pressure test is performed. The plug element then dissolves or disintegrates over time increasing fluid communication between the wellbore casing and the formation, thereby preparing the wellbore casing for stimulation operations without additional wellbore intervention after the casing pressure test. In certain embodiments, during or after dissolution of the plug element, clean-out of the bore of the valve is performed by the plug element.

Abstract: A frangible pressure control plug includes a first portion of a body adjacent a first end of the plug. A second portion of the body adjacent a second end of the plug. The second portion attached to the first portion in a first condition. A groove in the body interposed between the first portion and the second portion. A bore within the body passing through the first end and the first portion and inaccessible from the second end and wherein, fluid communication between the bore and the groove is prevented in the first condition and allowed in a second condition. Also included is a method of actuating a tool.

Abstract: A shifting sleeve has differential piston areas so that applied pressure displaces the sleeve against spring bias, which preferably is a series of Belleville washer stacks associated with modular mandrel components, to obtain the desired opposing force to the movement initiated with pressure applied to differential piston areas. An indexing feature is located between the sleeve and the mandrel passage wall and on a predetermined number of cycles disables the Belleville washer stacks from biasing the sleeve in an opposed direction as when pressure is applied. At this time the pressure in the mandrel acting on the differential piston area simply shifts the sleeve to open a lateral port so that fracturing through the cement that was earlier placed with the port closed can take place.

Abstract: A series of ball seat assemblies preferably used to open a series of sliding sleeves for formation access to a zone that is to be fractured allows sequential shifting of the sleeves with a single ball. The ball is guided by a tapered member with a lower outlet larger than the ball. The ball lands on the segments that are initially supported. Some leakage occurs between the segments but not enough to prevent pressure buildup to shift the sleeves. The tapered member closely fits to the segments to minimize leakage. Shifting the segments axially allows them to retract so the ball passes to eventually land on a non-leaking seat so that the zone can be fractured. The ball is recovered at the surface after passing the retracted segments and going through the undistorted opening in the tapered member.

Abstract: A tubing pressure operated sliding sleeve is used in cementing a tubular string. The sleeve is configured to hold closed as pressure builds to a predetermined value. When pressure is further raised a rupture disc blows and provides access to an integral piston disposed outside the sleeve. The back side of the piston is exposed to a low pressure or atmospheric chamber located between upper and lower seals. The sleeve thickness near the chamber can be made relatively thick to avoid flexing or bending under differential pressure because the net force to shift the sleeve is from differential pressure on the piston rather than the piston areas created by the upper and lower seals.

Abstract: Methods for preparing a wellbore casing for stimulation operations comprise the steps of cementing a wellbore casing in a wellbore, the wellbore casing having a downhole tool comprising a valve and an apparatus for restricting fluid flow through the valve, such as a ball seat, disposed above the valve. Actuation of the valve opens the valve to establish fluid communication between the wellbore casing and the formation. A plug element is disposed on a seat of the ball seat and a casing pressure test is performed. The plug element then dissolves or disintegrates over time increasing fluid communication between the wellbore casing and the formation, thereby preparing the wellbore casing for stimulation operations without additional wellbore intervention after the casing pressure test. In certain embodiments, during or after dissolution of the plug element, clean-out of the bore of the valve is performed by the plug element.

Abstract: A shifting tool for sleeves is supported on wireline or slickline and is pumped to the desired location by pressure from above delivered against the tool and passing around its periphery or against an articulated peripheral extending member that can optionally seal. Once in the vicinity of the desired sleeve to be shifted the shifting key is engaged to the sleeve and further applied pressure on the articulated peripheral seal shifts the sleeve in a downhole direction. The sleeve can also be shifted in an uphole direction with an anchor that grabs near the sleeve and a latch key that grabs the sleeve and is configured to retain grip as a motor moves the latch key uphole. Power can come from a wireline or can be locally provided if using slickline. The seal or extending member is retractable for tool removal or relocation.

Abstract: A frangible pressure control plug includes a first portion of a body adjacent a first end of the plug. A second portion of the body adjacent a second end of the plug. The second portion attached to the first portion in a first condition. A groove in the body interposed between the first portion and the second portion. A bore within the body passing through the first end and the first portion and inaccessible from the second end and wherein, fluid communication between the bore and the groove is prevented in the first condition and allowed in a second condition. Also included is a method of actuating a tool.

Abstract: A tubing pressure operated sliding sleeve is used in cementing a tubular string. The sleeve is configured to hold closed as pressure builds to a predetermined value. When pressure is further raised a rupture disc blows and provides access to an integral piston disposed outside the sleeve. The back side of the piston is exposed to a low pressure or atmospheric chamber located between upper and lower seals. The sleeve thickness near the chamber can be made relatively thick to avoid flexing or bending under differential pressure because the net force to shift the sleeve is from differential pressure on the piston rather than the piston areas created by the upper and lower seals.

Abstract: A series of ball seat assemblies preferably used to open a series of sliding sleeves for formation access to a zone that is to be fractured allows sequential shifting of the sleeves with a single ball. The ball is guided by a tapered member with a lower outlet larger than the ball. The ball lands on the segments that are initially supported. Some leakage occurs between the segments but not enough to prevent pressure buildup to shift the sleeves. The tapered member closely fits to the segments to minimize leakage. Shifting the segments axially allows them to retract so the ball passes to eventually land on a non-leaking seat so that the zone can be fractured. The ball is recovered at the surface after passing the retracted segments and going through the undistorted opening in the tapered member.

Abstract: A tubing pressure operated sliding sleeve is used in cementing a tubular string. The sleeve is configured to hold closed as pressure builds to a predetermined value. When pressure is further raised a rupture disc blows and provides access to an integral piston disposed outside the sleeve. The back side of the piston is exposed to a low pressure or atmospheric chamber located between upper and lower seals. The sleeve thickness near the chamber can be made relatively thick to avoid flexing or bending under differential pressure because the net force to shift the sleeve is from differential pressure on the piston rather than the piston areas created by the upper and lower seals.

Abstract: Methods for preparing a wellbore casing for stimulation operations comprise the steps of cementing a wellbore casing in a wellbore, the wellbore casing having a downhole tool comprising a valve and an apparatus for restricting fluid flow through the valve, such as a ball seat, disposed above the valve. Actuation of the valve opens the valve to establish fluid communication between the wellbore casing and the formation. A plug element is disposed on a seat of the ball seat and a casing pressure test is performed. The plug element then dissolves or disintegrates over time increasing fluid communication between the wellbore casing and the formation, thereby preparing the wellbore casing for stimulation operations without additional wellbore intervention after the casing pressure test. In certain embodiments, during or after dissolution of the plug element, clean-out of the bore of the valve is performed by the plug element.