Abstract: A resettable well stimulation tool is lowerable into a well bore on a length of tubing through which pressurized fluid may be forced into the tool to inflate a packer portion carried by the tool and then discharge a stimulation fluid into a portion of the well bore sealed off by the packer portion. During the inflation cycle of the tool pressurized fluid is forced downwardly into an annular tool body inflation chamber that communicates with an inflatable packer carried by the tool body. A perforated tube member coaxially carried in the inflation chamber serves to vertically distribute the inflation pressure along the length of the packer and assure its even inflation. In a straddle packer embodiment of the tool inflation and stimulation passages extend internally through the tool and are sealingly separated by an internal crossover structure, with the inflation passage being in communication with upper and lower packer members.

Abstract: An inflatable stimulation tool designed to be deployed by coil tubing having a shuttle valve which reciprocates within the bore of a tubular mandrel. The shuttle valve, in cooperation with a reciprocally movable outer mandrel which is disposed about an inner mandrel, opens and closes various ports in the device to alternately seal and unseal the inflatable packer element. The shuttle valve also operates to open and close a flow passage through the inner mandrel to permit the passage of various stimulation fluids through the tool and into the well bore.Upon deflation of the inflatable packing means, which leaves the packing means in a somewhat distended state, the element is urged to its original close relationship with the mandrel by a return spring which cooperates with the lower tool structure to which one end of the rubber packing element is clamped to longitudinally stretch the element.

Abstract: A system for determining the flow performance of a valve by first measuring certain flow parameters of the valve with the stem fixed in a plurality of different positions between full open and full closed and then calculating a value of flow coefficient for each. The flow parameters of the valve are then measured with the stem dynamically moving under a plurality of different flow conditions. Mathematical relationships are derived in accordance with certain procedures for calculating the flow rate of the valve under each of the different flow conditions.

Abstract: A gas lift valve of the unloading type having a main valve for controlling fluid flow between a well casing and a well tubing, a volume of compressible liquid a spaced distance from said main valve and subject to casing pressure, and a pilot valve between the main valve and the compressible liquid for controlling opening and closing of the main valve by permitting casing pressure to act thereon or to isolate it therefrom as the volume of the compressible liquid changes in response to changes in casing pressure to which it is subjected. Gas lift well systems utilizing such gas lift valves and methods for operating such gas lift well systems are also disclosed.

Abstract: A fluid flow regulator in which the fluid flow therethrough is restricted twice, first through a fixed orifice in a slidable piston and then through a variable flow restrictor which is a spring. This spring is axially aligned with and bears against the piston, and fluids issuing from the orifice empties into the interior of the spring, the end of the spring opposite the piston being closed. Fluids thus flow from within the spring through the gaps between its coils and into a chamber surrounding the spring, and from there exits through the outlet of the regulator. The gaps between the spring coils are quite narrow and cause the flow of fluids to be restricted this second time. This restriction is variable since the piston moves as the differential pressure thereacross varies which causes the length of the spring to vary accordingly. This in turn varies the size of the gaps. In this manner, the regulator compensates automatically to provide a fluid flow rate which is substantially constant.