Abstract: This application discloses a protection circuit associated with a battery management system (BMS). The protection circuit includes a first protection module and a freewheeling module. The first protection module is connected in parallel to a first switch module of the BMS, and the freewheeling module is connected in parallel to a load module of the BMS. The first protection module switches to a charging state when the first switch module is turned off to stabilize a voltage between a first terminal of the first switch module and a second terminal of the first switch module. The freewheeling module is turned on when the first switch module is turned off to stabilize a voltage between the first switch module and the second switch module. The protection circuit mitigates risks of breakdown of the first switch module, and prevents a parasitic inductance from limiting a switching frequency of the first switch module.

Abstract: A control method and device of a voltage converter and a voltage control system are provided. In some embodiments, the control device includes a first control module configured to obtain a current reference value according to an output voltage of a voltage converter and a given voltage value; a current modulation module configured to reduce the current reference value when an output current of a voltage converter is greater than a first current threshold; and a second control module configured to control the output current of a voltage converter according to the reduced current reference value and an output current.

Abstract: A sliding sleeve device has an outer cylinder, a circulation hole being provided in the wall of the outer cylinder; and an inner cylinder provided in an inner cavity of the outer cylinder. In an initial state, the inner cylinder and the outer cylinder are fixed to each other to seal the circulation hole. In a first state, the inner cylinder is movable relative to the outer cylinder, thereby unsealing the circulation hole. A protection mechanism is provided in the circulation hole, which has an inner member located on the radially inner side and an outer member located on the radially outer side.

Abstract: A method and apparatus for forming tungsten features in semiconductor devices is provided. The method includes exposing a top opening of a feature formed in a substrate to a physical vapor deposition (PVD) process to deposit a tungsten liner layer within the feature. The PVD process is performed in a first processing region of a first processing chamber and the tungsten liner layer forms an overhang portion, which partially obstructs the top opening of the feature. The substrate is transferred from the first processing region of the first processing chamber to a second processing region of a second processing chamber without breaking vacuum. The overhang portion is exposed to nitrogen-containing radicals in the second processing region to inhibit subsequent growth of tungsten along the overhang portion. The feature is exposed to a tungsten-containing precursor gas to form a tungsten fill layer over the tungsten liner layer within the feature.

Abstract: A new sliding sleeve relates to the technical field of oil and gas well completion and reservoir stimulation, comprising an upper connector, a lower connector, an outer housing, an inner sleeve and a shear pin. The upper connector and the lower connector are respectively connected to two ends of the outer housing, and the inner sleeve is locked in the outer housing via the shear pin, wherein a flow guiding hole is provided in the outer housing, and the inner sleeve can open or close the flow guiding hole, wherein at least two grooves for engaging with at least two corresponding tooth-shaped elements on a sliding sleeve opening tool are disposed along an axial direction in the inner sleeve, and wherein an erosion-resistant ring is embedded in the groove, and an inner diameter of the erosion-resistant ring is larger than or equal to an inner diameter of the inner sleeve.

Abstract: A sliding sleeve device has an outer cylinder, a circulation hole being provided in the wall of the outer cylinder; and an inner cylinder provided in an inner cavity of the outer cylinder. In an initial state, the inner cylinder and the outer cylinder are fixed to each other to seal the circulation hole. In a first state, the inner cylinder is movable relative to the outer cylinder, thereby unsealing the circulation hole. A protection mechanism is provided in the circulation hole, which has an inner member located on the radially inner side and an outer member located on the radially outer side.

Abstract: A wellbore staged operation method, includes running, after a first well drifting operation is performed on a wellbore, a pipe string (100) in the wellbore, wherein the pipe string (100) includes, along a direction from bottom to top, a floating hoop (2), a plug seat (7), a toe-end sliding sleeve (3), and a fracturing sliding sleeve (4); performing a cementing operation, wherein cement slurry pumped into an inner chamber of the pipe string (100) enters an annulus between the pipe string and the wellbore through the plug seat (7) and the floating hoop (2) to form a cement sheath, the cement sheath isolating the toe-end sliding sleeve (3) from the fracturing sliding sleeve (4); performing a second drifting operation to ensure the toe-end sliding sleeve (3) of the pipe string (100) exposed; performing a pressure test for the pipe string; and performing staged fracturing constructions.

Abstract: A sliding sleeve opening tool includes an engaging element, a ball seat and a guiding head connected in sequence, as disclosed herein. The engaging element includes at least two elastic pawls uniformly disposed in a circumferential direction and at least one engaging part disposed on an external circumferential surface of an elastic pawl, and the engaging element is further provided with a first fluid channel which runs through the engaging element. The ball seat is provided with a second fluid channel which runs through the ball seat, and within the second fluid channel a taper hole section for bearing a sealing ball is disposed, the second fluid channel being in communication with the first fluid channel. The guiding head is provided with a third fluid channel which runs through the guiding head, and the third fluid channel is in communication with the second fluid channel.

Abstract: A device for perforating, packing, and fracturing and a tubing string comprising the device are disclosed, wherein the device comprises an upper connector, a nozzle sleeve, a mandrel, a packer, a lower connector, a first inner sleeve provided inside the upper connector, and a second inner sleeve provided inside the nozzle sleeve, further wherein the upper connector is provided with a fracturing hole, and a nozzle is provided at the nozzle sleeve.

Abstract: A tool for perforating, packing and fracturing and a tubing string comprising the tool are disclosed. The tool comprises an upper connector, a connection sleeve, a mandrel, a packer, a lower connector, and an inner sleeve. The upper connector is provided with communication holes, and a nozzle is provided at each communication hole. The inner sleeve is provided on an inner wall of the upper connector to block the nozzle. Under an action of a fracturing fluid, the inner sleeve moves downwards to expose the nozzle, and the packer is packed. Then, perforating is performed through the nozzle. After perforating is finished, the nozzle is configured to be lost at a communication hole, and then fracturing is performed. When the tool is used, operation cost can be reduced, and reservoir stimulation effect can be improved.

Abstract: A device for perforating, packing and fracturing and a tubing string comprising the device are disclosed. The device comprises an upper connector, a nozzle sleeve, a mandrel, a packer, a lower connector, a first inner sleeve provided inside the upper connector, and a second inner sleeve provided inside the nozzle sleeve. The upper connector is provided with a fracturing hole, and a nozzle is provided at the nozzle sleeve. In an initial state, the first inner sleeve blocks the fracturing hole, and the second inner sleeve blocks the nozzle. After an internal flowbore of the second inner sleeve is blocked, a fracturing fluid is pumped into the device. When a pressure reaches a first pressure, the second inner sleeve moves downwards to expose the nozzle and the packer is packed. At this time, perforation can be performed. After perforation is finished, the fracturing fluid is pumped into an annulus. When the pressure reaches a second pressure, the first inner sleeve moves downwards to expose the fracturing hole.

Abstract: A new sliding sleeve relates to the technical field of oil and gas well completion and reservoir stimulation, and the new sliding sleeve includes an upper connector, a lower connector, an outer housing, an inner sleeve and a shear pin, as disclosed herein. The upper connector and the lower connector are respectively connected to two ends of the outer housing, and the inner sleeve is locked in the outer housing via the shear pin. A flow guiding hole is provided in the outer housing, and the inner sleeve can open or close the flow guiding hole. At least two grooves for engaging with at least two corresponding tooth-shaped elements on a sliding sleeve opening tool are disposed along an axial direction in the inner sleeve. An erosion-resistant ring is embedded in the groove, and an inner diameter of the erosion-resistant ring is larger than or equal to an inner diameter of the inner sleeve.

Abstract: A sliding sleeve opening tool includes an engaging element, a ball seat and a guiding head connected in sequence, as disclosed herein. The engaging element includes at least two elastic pawls uniformly disposed in a circumferential direction and at least one engaging part disposed on an external circumferential surface of an elastic pawl, and the engaging element is further provided with a first fluid channel which runs through the engaging element. The ball seat is provided with a second fluid channel which runs through the ball seat, and within the second fluid channel a taper hole section for bearing a sealing ball is disposed, the second fluid channel being in communication with the first fluid channel. The guiding head is provided with a third fluid channel which runs through the guiding head, and the third fluid channel is in communication with the second fluid channel.

Abstract: A tool for perforating, packing and fracturing and a tubing string comprising the tool are disclosed. The tool comprises an upper connector, a connection sleeve, a mandrel, a packer, a lower connector, and an inner sleeve. The upper connector is provided with communication holes, and a nozzle is provided at each communication hole. The inner sleeve is provided on an inner wall of the upper connector to block the nozzle. Under an action of a fracturing fluid, the inner sleeve moves downwards to expose the nozzle, and the packer is packed. Then, perforating is performed through the nozzle. After perforating is finished, the nozzle is configured to be lost at a communication hole, and then fracturing is performed. When the tool is used, operation cost can be reduced, and reservoir stimulation effect can be improved.