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: A method and apparatus for installing an array of sensors in a wellbore wherein the sensors are incorporated into the lower end of a transmission cable which, in turn, is used to lower the array into the wellbore. A load-bearing cable is simultaneously run into the wellbore side-by-side with the transmission cable and the two cables are clamped together at spaced intervals whereby a substantial portion of the tensile forces in the transmission cable is transferred to the load-bearing cable.