Abstract: Temporary plugs are formed in process flowlines by injecting into the flowlines a plugging material having a freezing point only slightly below the ambient temperature. The plugging material is frozen in place, and a servicing operation is conducted on the flowline. The plugging material is then allowed to thaw or is thawed by applied heat. Linear primary alcohols and normal paraffinic hydrocarbons are preferred plugging materials.

Abstract: An apparatus and method for selectively disconnecting a wireline from a downhole tool when the tool becomes lodged in an oil or gas well. The apparatus is directed to a wireline releasing device which includes a precharge chamber which can be pressurized to a predetermined amount for applying a force against a piston assembly located within the releasing device to hold together telescopically connected upper and lower tubular portions which are locked in place by retractable dogs which extend through aligned openings in the upper and lower tubular portions. The device is intended to be connected at one end to a length of wireline and, to another end, to the top of the downhole tool. During wireline operations, upon the downhole tool becoming lodged within the well, the wireline operator applies hydraulic or pneumatic pressure from the surface which exceeds the precharged pressure, which acts to disconnect the upper portion of the device from the lower portion and the downhole tool.

Abstract: An apparatus and method for selectively disconnecting a wireline from a downhole tool when the tool becomes lodged in an oil or gas well. The apparatus is directed to a wireline releasing device which includes a precharge chamber which can be pressurized to a predetermined amount for applying a force against a piston assembly located within the releasing device to hold together telescopically connected upper and lower tubular portions which are locked in place by retractable dogs which extend through aligned openings in the upper and lower tubular portions. The device is intended to be connected at one end to a length of wireline and, to another end, to the top of the downhole tool. During wireline operations, upon the downhole tool becoming lodged within the well, the wireline operator applies hydraulic or pneumatic pressure from the surface which exceeds the precharged pressure, which acts to disconnect the upper portion of the device from the lower portion and the downhole tool.

Abstract: A pump for circulating fluids downhole. The rotor of a positive displacement pump transmits torque from the upper drill string section to a tool attached to the lower end of the pump. Bow springs prevent the stator portion of the pump from rotating in the wellbore. Fluid is counterflowed up the interior of the drill string by the positive displacement pump through a check valve into a settling chamber. Cuttings or other solids settle out of the fluid and the fluid is then pumped out through one or more discharge ports to the lowermost end of the drill string.