A jet flow adjustment method for rotary steerable downhole release relates to a technical field of downhole drilling equipment for oil wells, which includes steps of: defining a diversion ratio p of a jet nozzle (2) by a ground control system according to a cleaning requirement of a cuttings bed; and sending the diversion ratio p of the jet nozzle (2) to a control unit of a downhole rotary steerable system; and determining an opening area s of the jet nozzle (2) by the control unit of the downhole rotary steerable system according to the diversion ratio p of the jet nozzle (2) and an equivalent channel area S of a drilling tool, wherein a calculation formula is: s=p*S/(1−p); controlling an adjustable bypass valve (3) by the control unit of the downhole rotary steerable system according to the calculated opening area s of the jet nozzle (2), so as to control an overlapping area between sector holes (9) of a rotor end (7) and a stator end (8), thereby opening the jet nozzle (2) for release. The present invention has simple control and strong release ability, which can effectively solve the jamming problem of the rotary steerable downhole tool.

Methods and apparatus for retrieving a fish from a wellbore. A method includes introducing a specialized fishing tool into the wellbore. The specialized fishing tool includes a fishing subassembly comprising a nonreflective interior, a shroud coupled to the fishing subassembly, and a camera disposed at least partially within the shroud and configured to view the interior of the fishing subassembly. The specialized fishing tool is conveyed downhole in the wellbore to a location of the fish. The fish is visualized with the camera. The fish is coupled to the fishing subassembly, and the fish is retrieved from the wellbore.

Methods and apparatus for retrieving a fish from a wellbore. A method includes introducing a specialized fishing tool into the wellbore. The specialized fishing tool includes a fishing subassembly comprising a nonreflective interior, a shroud coupled to the fishing subassembly, and a camera disposed at least partially within the shroud and configured to view the interior of the fishing subassembly. The specialized fishing tool is conveyed downhole in the wellbore to a location of the fish. The fish is visualized with the camera. The fish is coupled to the fishing subassembly, and the fish is retrieved from the wellbore.

A drilling assembly includes a drill string configured to be disposed within a wellbore. The drilling assembly also includes a sub fluidically coupled to the drill string. The sub includes a mandrel fixed to the drill string and defines an external helically undulated surface and a bore configured to flow drilling fluid received from the drill string. The sub includes a sleeve rotationally coupled to and disposed outside the mandrel. The sleeve has an internal helically undulated surface corresponding with the external helically undulated surface of the mandrel to form, with the mandrel, a progressive cavity. The progressive cavity receives fluid from the bore of the mandrel to rotate the sleeve as the drilling fluid flows along the cavity. The sub also includes a valve configured to regulate a flow of the drilling fluid along the bore to direct fluid toward or away from the progressive cavity.

A method for regulating a downhole fluid flow rate, in at least some embodiments, comprises partitioning a fluid circulation system into a sequence of segments, the sequence including a pump segment at one end and a drill bit segment at another end; obtaining a desired pressure for the drill bit segment; determining, for each of the segments in the sequence except for the drill bit segment, a desired pressure based at least in part on the desired pressure for a preceding segment in the sequence; determining a pump setting based on the desired pressure for the pump segment; and applying the pump setting to a pump used to move drilling fluid through the fluid circulation system.

A wellbore tool assembly to release stuck pipe includes a tubular that includes an outer wall, an inner wall and an annular compartment defined between the outer wall and the inner wall. A quantity of acid is carried within the annular compartment of the tubular. Multiple ports are formed in the tubular. Each port fluidically connects an inner volume of the tubular with a volume outside the tubular through the annular compartment. The assembly includes a ball seat disposed within the tubular. The ball seat is configured to receive a ball dropped into the tubular. The multiple ports are configured to switch between an open position and a closed position. When in the open position, the multiple ports permit flow of the acid from the annular compartment to the formation. When in the closed position, the multiple ports prevent fluid flow from the annular compartment to the formation.

A wellbore tool assembly to release stuck pipe includes a tubular that includes an outer wall, an inner wall and an annular compartment defined between the outer wall and the inner wall. A quantity of acid is carried within the annular compartment of the tubular. Multiple ports are formed in the tubular. Each port fluidically connects an inner volume of the tubular with a volume outside the tubular through the annular compartment. The assembly includes a ball seat disposed within the tubular. The ball seat is configured to receive a ball dropped into the tubular. The multiple ports are configured to switch between an open position and a closed position. When in the open position, the multiple ports permit flow of the acid from the annular compartment to the formation. When in the closed position, the multiple ports prevent fluid flow from the annular compartment to the formation.

Provided here are methods and system to detect an untethered device in a wellhead. The untethered device includes a housing, a transducer, and one or more sensors configured to measure data along the subterranean well. The transducer emits acoustic signals that are received by microphones on the surface of the wellhead. Based on these acoustic signals, the location of the untethered device is determined and appropriate valves may be opened or closed by an operator.

Alkyl ester spotting fluid compositions and processes for freeing differentially stuck pipe are provided. An alkyl ester spotting fluid composition includes an invert emulsion having an alkyl ester as the external phase and water as the internal phase. In some embodiments, the alkyl ester spotting fluid composition may include the alkyl ester invert emulsion and an emulsifier. The alkyl ester spotting fluid composition may be introduced downhole in the vicinity of a portion of a differentially stuck pipe such that the spotting fluid composition contacts the mudcake and frees the differentially stuck pipe.

A buoyancy assist tool has an outer case with a rupture disk assembly connected therein. The buoyancy assist tool defines the upper end of a buoyancy chamber in a well casing. A sleeve in the outer case traps the rupture disk membrane after it has ruptured to provide full bore flow through the casing.