Abstract: A plug for use in a wellbore has a piston that is movable on a body. A control valve is disposed in communication between the wellbore and a piston chamber and can capture wellbore pressure in the piston chamber. A closure on the body can transition from a closed condition to an open condition relative to the port in response to the movement of the piston. A fixture releasably holds the closure in the closed condition on the body. The fixture releases in response an increased pressure differential on the piston above an initial pressure differential between the captured chamber pressure and the wellbore pressure.

Abstract: A multistage cementing assembly is used for cementing casing in a borehole. A subsurface tool on the casing holds a subsurface plug therein using a temporary retainer. The subsurface plug is located in a subsurface location below one or more stage tools or cementing collars on the casing. First stage cement passing down the casing can pass through a passage of the subsurface plug to flow out of a float valve. A wiper plug passed through the casing behind the cement is then engaged with the subsurface plug. Pressure buildup can release the two plugs as a unit from the temporary retainer. Before reaching the float valve, a deformable ring on the subsurface plug can engage in a locator ring on the casing to indicate the plug unit's location during operations. Eventually, additional stages can be cemented using the one or more stage tools uphole on the casing.

Abstract: A plug for use in a wellbore has a piston that is movable on a body. A control valve is disposed in communication between the wellbore and a piston chamber and can capture wellbore pressure in the piston chamber. A closure on the body can transition from a closed condition to an open condition relative to the port in response to the movement of the piston. A fixture releasably holds the closure in the closed condition on the body. The fixture releases in response an increased pressure differential on the piston above an initial pressure differential between the captured chamber pressure and the wellbore pressure.

Abstract: A multistage cementing assembly is used for cementing casing in a borehole. A subsurface tool on the casing holds a subsurface plug therein using a temporary retainer. The subsurface plug is located in a subsurface location below one or more stage tools or cementing collars on the casing. First stage cement passing down the casing can pass through a passage of the subsurface plug to flow out of a float valve. A wiper plug passed through the casing behind the cement is then engaged with the subsurface plug. Pressure buildup can release the two plugs as a unit from the temporary retainer. Before reaching the float valve, a deformable ring on the subsurface plug can engage in a locator ring on the casing to indicate the plug unit's location during operations. Eventually, additional stages can be cemented using the one or more stage tools uphole on the casing.

Abstract: A running tool sets and cements a liner in a borehole. While the tool's bypass section is closed, a plug deployed to the tool diverts hydraulic pressure to set a liner hanger in the borehole. The setting plug is unseated, and the bypass section is switched opened by deploying another plug to an opening seat and shifting a control sleeve open relative to a bypass port. While the tool's packoff remains sealed in the hanger, cement pumped out the bypass port is bullheaded into a lap of the liner and borehole. When cementing is complete, the bypass section is switched closed by deploying another plug to a closing seat and shifting the control sleeve closed relative to the bypass port. The bypass section is then placed in a flow-through condition where fluid communication is reestablished through the tool to the liner by allowing fluid to flow past the plugs in the tool.

Abstract: A running tool sets and cements a liner in a borehole. While the tool’s bypass section is closed, a plug deployed to the tool diverts hydraulic pressure to set a liner hanger in the borehole. The setting plug is unseated, and the bypass section is switched opened by deploying another plug to an opening seat and shifting a control sleeve open relative to a bypass port. While the tool’s packoff remains sealed in the hanger, cement pumped out the bypass port is bullheaded into a lap of the liner and borehole. When cementing is complete, the bypass section is switched closed by deploying another plug to a closing seat and shifting the control sleeve closed relative to the bypass port. The bypass section is then placed in a flow-through condition where fluid communication is reestablished through the tool to the liner by allowing fluid to flow past the plugs in the tool.

Abstract: A stage tool used in a wellbore has a housing consisting of two sub-housings that couple together. A first sleeve is movably disposed in the housing bore and is held closed with a temporary connection relative to a side port of the housing. The first sleeve has a first seat of millable material. A second sleeve is also movably disposed in the housing bore and is held opened with a temporary connection relative to the side port. The second sleeve has a second seat of millable material. An opening plug is landed on the first seat so pressure can break the connection and shift the first sleeve open relative to the side port. After pumping cement out of the tool, a closing plug is pumped to the second seat so pressure can break the connection and shift the second sleeve closed relative to the side port. The first sleeve includes a bypass that allows for fluid to pass beyond the seated plug.

Abstract: A cementing port collar has an opening sleeve biased from a closed position to an opened position relative to the collar's exit port, and a first restraint temporarily holds the opening sleeve closed. The collar also has a closing sleeve biased from an opened position to a closed position, and a second restraint temporarily holds the closing sleeve opened. During cementing, the first restraint is electronically activated with a first trigger to release the opening sleeve opened so cement slurry can pass out of the collar's exit port to the borehole annulus. When cementing is completed, the second restraint is electronically activated with a second trigger to release the closing sleeve closed to close off the collar to the borehole so the cement can set. The restraints can include bands of synthetic fiber, which are burned by fuses activated by a controller of the collar responding to passage of RFID tags.

Abstract: A straddle apparatus deploys in a borehole with tubing to treat different formation zones. The apparatus has packer elements and a flow element. The packer elements have fill ports in fluid communication with the tubing and have packer valves. These packer valves are biased to open fluid communication between the elements and the fill port so the elements can be inflated to seal off a borehole section. The flow unit has a flow port in fluid communication with the tubing and has a flow valve biased to close fluid communication between the flow port and the borehole. Once the elements inflate, a control unit electronically activate the packer valves to close fluid communication between the elements and the fill ports. Then, the control units electronically activates the flow valve to open fluid communication between the flow port and the borehole so treatment can be applied to the formation zone.

Abstract: A cementing port collar has an opening sleeve biased from a closed position to an opened position relative to the collar's exit port, and a first restraint temporarily holds the opening sleeve closed. The collar also has a closing sleeve biased from an opened position to a closed position, and a second restraint temporarily holds the closing sleeve opened. During cementing, the first restraint is electronically activated with a first trigger to release the opening sleeve opened so cement slurry can pass out of the collar's exit port to the borehole annulus. When cementing is completed, the second restraint is electronically activated with a second trigger to release the closing sleeve closed to close off the collar to the borehole so the cement can set. The restraints can include bands of synthetic fiber, which are burned by fuses activated by a controller of the collar responding to passage of RFID tags.

Abstract: A cementing port collar has an opening sleeve biased from a closed position to an opened position relative to the collar's exit port, and a first restraint temporarily holds the opening sleeve closed. The collar also has a closing sleeve biased from an opened position to a closed position, and a second restraint temporarily holds the closing sleeve opened. During cementing, the first restraint is electronically activated with a first trigger to release the opening sleeve opened so cement slurry can pass out of the collar's exit port to the borehole annulus. When cementing is completed, the second restraint is electronically activated with a second trigger to release the closing sleeve closed to close off the collar to the borehole so the cement can set. The restraints can include bands of synthetic fiber, which are burned by fuses activated by a controller of the collar responding to passage of RFID tags.

Abstract: A cementing port collar has an opening sleeve biased from a closed position to an opened position relative to the collar's exit port, and a first restraint temporarily holds the opening sleeve closed. The collar also has a closing sleeve biased from an opened position to a closed position, and a second restraint temporarily holds the closing sleeve opened. During cementing, the first restraint is electronically activated with a first trigger to release the opening sleeve opened so cement slurry can pass out of the collar's exit port to the borehole annulus. When cementing is completed, the second restraint is electronically activated with a second trigger to release the closing sleeve closed to close off the collar to the borehole so the cement can set. The restraints can include bands of synthetic fiber, which are burned by fuses activated by a controller of the collar responding to passage of RFID tags.

Abstract: A straddle apparatus deploys in a borehole with tubing to treat different zones of a formation. The apparatus has first and second packer elements and a flow element disposed on the apparatus. The first and second packer elements have fill ports in fluid communication with the tubing and have packer valves. These packer valves are biased to open fluid communication between the packer elements and the fill port so the packer elements can be inflated to seal off a section of the borehole when fluid pressure is applied down the tubing string. The flow unit has a flow port in fluid communication with the tubing and has a flow valve biased to close fluid communication between the flow port and the borehole. Once the elements inflate, one or more control units on the apparatus electronically activate the at packer valves to close fluid communication between the packer elements and the fill ports.