Abstract: Fractures are initiated or extended into fluid producing earth formations from a well by providing a reservoir of high pressure gas at the earth's surface together with a flow control valve or a frangible closure, such as a shear disk, interposed in a conduit connecting the reservoir to the well. The well is precharged with high pressure gas at a pressure less than or about the same as the reservoir gas pressure. Fracture initiation and/or extension may be carried out by firing the perforation gun and opening the flow control valve between the reservoir and the wellhead in timed relation or by allowing a pressure drop across a shear disk interposed between the reservoir and the wellhead to effect rupture of the shear disk to release the reservoir charge.

Abstract: Perforations and other openings in well casings, liners and other conduits may be substantially blocked or sealed to prevent fluid flow between the casing or liner interior and an earth formation by placing a radially expansible sleeve adjacent the perforations or openings and urging the sleeve into forcible engagement with the casing or inner wall using an explosive charge. An apparatus including a radially contracted sleeve formed by a coiled plate member or a tubular member having flutes defined by external and internal folds, may be deployed into a well casing or liner through a production or injection tubing string and on the end of a flexible cable or coilable tubing. An explosive charge disposed on the apparatus and within the sleeve may be detonated to urge the sleeve into forcible engagement with the casing inner wall.

Abstract: Perforations and cracks in wellbore liners or casings may be temporarily or permanently covered by a radially-expansible, coiled sleeve member formed by a sheet of elastically-deflectable material such as stainless steel which is coiled and placed in a cylinder which may be conveyed into a well to a working position for deployment of the sleeve to expand into engagement with the casing wall to block the perforations or cracks. The cylinder includes a sleeve ejecting piston which may be urged to rapidly eject the sleeve from the cylinder by pressure fluid conveyed to the cylinder by coilable tubing or by a gas-generating charge material electrically connected to an E-line which also may be used to deploy the cylinder into its working position in the well.

Abstract: Hydraulic fractures are initiated or extended into earth formations from a first well by filling a space within the wellbore and a tubing string extending within the well with a fracturing fluid, placing the first well in fluid flow communication with a tubing string extending within a second well and increasing the pressure of fluid in the respective tubing strings sufficient to initiate or extend the fracture. The second well serves as an accumulator for accumulating a sufficient charge of pressure fluid, such as gas, to drive the fracturing fluid in the first well into the formation to a suitable extent.