A downhole tool that has a plurality of arm assemblies. Each of the arm assemblies has an arm configured to expand and retract and an actuator. A hydraulic bus in fluid communication with the plurality of arm assemblies. A plurality of flow control devices. The flow control devices are configured to selectively isolate one or more arm assemblies of the plurality of arm assemblies from the hydraulic bus while maintaining the other arm assemblies of the plurality of arm assemblies in communication with the hydraulic bus.

A spacer insertion device is disclosed. The spacer insertion device comprises a spacer insertion mechanism fixed on a base body of a core detection device of a coring instrument, wherein the spacer insertion mechanism comprises a slider and a cylinder body, an output end of the cylinder body is connected with the slider, and the slider is slidably connected with the base body to push a spacer to the a core channel provided in the base body and in communication with a core barrel.

A casing mill having a main body with cutter bases with cutters mounted on the cutter bases. The cutter bases are moved radially by operating arms which are rotatably attached to the main body, which are in turn moved by an operating mechanism in response to fluid flow through. One or more of the operating arms are extended to form a cutout arm, which enables cutting an initial window in a casing string, from which milling can continue. The operating arms are mounted to the main body by pins, which are held in the main body by a pin retaining arrangement.

The disclosure of this application is directed to a downhole tool comprising a central element/member and a sleeve that is rotatably and orbitally disposed around the central element/member. The sleeve rotates and orbits around the central element/member responsive to fluid flowing through the downhole too. The disclosure is also related to a method of advancing the downhole tool in a well by flowing fluid through the tool.

A perforation system includes: a perforating tool including a main body and a perforating head disposed within the main body; a wireline electrically coupled to the perforating head; a pulse generator electrically coupled to the wireline; and a power supply electrically coupled to the pulse generator. Upon electrification of the perforating head, a spark discharged from the perforating head arcs to a perforation target location.

A centralizer assembly replaces an existing centralizer of a wireline tool so the tool can be used with smaller casing, such as casing smaller than 6-in. The assembly includes first and second centralizer units that replace the existing centralizer on a mandrel. Each unit has a sleeve that fits in a recess of the mandrel, and each unit has slider blocks disposed together in the recess on opposing sides of a divider on the sleeve. Arms hingedly connected to the blocks on each unit connect together at a joint having a roller for engaging in the casing. On each unit, a common pin is disposed through the slider blocks, and biasing elements on the common pin bias the blocks toward one another with different amounts of bias.

A method of drilling a wellbore includes running a drilling assembly into the wellbore through a casing string, the drilling assembly having a tubular string, a stabilizer, and a drill bit; applying a force to an arm of the stabilizer, thereby causing the arm to retract; and removing the stabilizer and the drill bit from the wellbore.

The present invention relates to a stabilizing system (100, 200, 300) adapted to be used in a drilling system, wherein the transversal diameter of the stabilizing system (100, 200, 300) increases when drilling forces are applied onto the stabilizing system (100, 200, 300). The invention further comprises a corresponding method for drilling a hole.

A centralizer system and a method for centralizing a casing in a well bore before cementing of the casing in the well bore is disclosed, where the centralizer system comprises at least one centralizer which is adapted for mounting on the casing where the at least one centralizer comprises a receiving unit capable of receiving a wireless signal in form of a pressure wave and a wireless signal generator for generation and transmission of a wireless signal in form of a pressure wave which the receiving unit of the at least one centralizer is capable of receiving. The at least one centralizer is further configured such that the centralizer is activated for centralizing of the casing when the receiving unit receives a wireless signal transmitted by the signal generator.

A centralizer device for center positioning of a bore hole component (90, 91) in a bore hole and a method for deploying such a centralizer are described. The centralizer device (100) is prepared to have two possible different states, one state being a locked state for improved deployment and another state being a released state for centring. The transition from the locked state to the released state is performed by introducing a pill of bore fluid having a pH-value outside range of pH-values of bore fluid in a well. The pill of bore fluid dissolves pH-soluble material in the centralizer device.