Abstract: Apparatus and methods are provided for coupling a body member to a cylindrical member having a radially outward extending shoulder thereon. A coupling includes the body member and an annular seal for sealing between the body member and the cylindrical member. A plurality of collet sections are disposed around the body member, each of the collet sections having an upper end connected to the body member and having a lower end adapted for engagement with a lower end surface of the shoulder of the cylindrical member. An outer sleeve is slidably disposed about the plurality of collet sections and is slidable relative to the collet sections between an open position wherein the lower ends of the collet sections may receive the shoulder of the cylindrical member therebetween, and a closed position wherein the body member is sealingly coupled to the cylindrical member.

Abstract: A circulation valve includes a cylindrical housing having an open bore therethrough and a circulating port through a wall thereof. A valve mandrel is slidably received in the housing and movable from a closed position closing the circulating port to an open position opening the circulating port. The circulating port is in fluid communication through an inner bore of the valve mandrel with the open bore of the housing above the valve mandrel when the valve mandrel is in its open position. A shear pin initially retains the valve mandrel in its closed position. A spring moves the valve mandrel to its open position upon shearing of the shear pin.

Abstract: Apparatus and methods are provided for taking a sample of a fluid in a well. The apparatus comprising a housing, a telescoping sampler assembly having a sleeve valve therein, an actuating mandrel and a time delay fluid control device which controls the opening of the sleeve valve. The method of operation of the sampler comprising evacuating the sample chamber of the sampler assembly, lowering the sampler assembly into a well, and collecting a fluid sample by flowing fluid into the sampler assembly from the well by opening and closing a sleeve valve in the sampler assembly utilizing a continuous sliding movement.

Abstract: A flameless nitrogen vaporizing unit includes a first internal combustion engine driving a nitrogen pump through a transmission. Connected to the transmission is a transmission retarder for varying the load on the first internal combustion engine by varying a level of hydraulic fluid present in the transmission retarder. A second internal combustion engine drives three hydraulic oil pumps against a variable back pressure so that a variable load may be imposed upon the second engine. Liquid nitrogen is pumped from the nitrogen pump driven by the first engine into a first heat exchanger where heat is transferred from exhaust gases from the first and second internal combustion engines to the liquid nitrogen to cause the nitrogen to be transformed into a gaseous state. The gaseous nitrogen then flows into a second heat exchanger where it is superheated by an engine coolant fluid to heat the gaseous nitrogen to essentially an ambient temperature. The superheated nitrogen is then injected into the well.