Abstract: The present invention is a surface controlled subsurface safety valve (SCSSV) for use in a well, preferably a hydrocarbon producing well. The SCSSV comprises a valve body having a longitudinal bore for fluid to flow through, a bore closure assembly, a pressure balanced drive assembly, and a fail safe assembly. The bore closure assembly is positioned and normally biased to close the bore to fluid flow. The drive assembly is coupled to the bore closure assembly for driving the bore closure assembly to an open position. The fail safe assembly is positioned and configured to hold the bore closure assembly in the open position in response to a hold signal and to release the valve to return to the safe, closed position upon interruption of the hold signal.

Abstract: The present invention is a surface controlled subsurface safety valve (SCSSV) for use in a well, preferably a hydrocarbon producing well. The SCSSV comprises a valve body having a longitudinal bore for fluid to flow through, a bore closure assembly, a pressure balanced drive assembly, and a fail safe assembly. The bore closure assembly is positioned and normally biased to close the bore to fluid flow. The drive assembly is coupled to the bore closure assembly for driving the bore closure assembly to an open position. The fail safe assembly is positioned and configured to hold the bore closure assembly in the open position in response to a hold signal and to release the valve to return to the safe, closed position upon interruption of the hold signal.

Abstract: A downhole inspection tool is attached to the lower end of a length of coiled tubing having an electrical/fiberoptic cable threaded through the center. The coiled tubing carries a flow of optically clear and/or acoustically homogeneous fluid from a supply of such fluid at the surface. The tool itself includes a cable head subassembly module attached to the lower end of the coiled tubing and terminates the electrical and optical conductors within the cable. An inspection module for producing an electrical signal indicative of downhole conditions is detachably connected to the lower end of the cable head assembly module. An outer flow tube is mechanically connected to the inspection module and surrounds both of the modules to define an annular space therebetween.

Abstract: A system for the inspection of a well borehole and the formation around the borehole. The system includes a sealed tubing at the lower end of which is mounted a fiberoptic telemetry module which receives various sensor modules for transmissions of sensed information to the surface. The modular telemetry link and sensor include fluid passageways through which fluid pumped from the surface down the sealed tubing may pass to create a region of optically clear and/or acoustically homogenous fluid in the borehole in the vicinity of the modular telemetry link and sensor. The passage of fluid through the passageways in the modular equipment may also serve to cool the circuits thereof.

Abstract: A system for the inspection of a well borehole and the formation around the borehole. The system includes a pair of concentric reeled tubings for injecting a pair of fluids into a wellbore through a wellhead, one of said fluids being an optically transparent or acoustically homogenous fluid which forms a slug of said fluid around an optical sensor which transmits signals indicative of well conditions to the surface. The other of said fluids is used to perform functions with respect to said sensor such as cooling said sensor or protect it from a corrosive environment. In addition, a fiberoptic cable construction in combination with the reel tubing is also disclosed.