Abstract: A borehole cable includes a plurality of geophone-containing modules spaced apart along the cable by a plurality of conduit sections and designed for acoustic, thermal and pressure imaging of the subsurface. Each cable conduit section comprises an inner core of flexible tubing and an outer wall of interlock completely surrounding the core. The inner corrugated core is designed to compress under the external pressure applied by the formation in which it is deployed. The percent of core compression is controlled by adjusting the composition and structure of the inner core and the outer interlock wall. Compression of the inner core beyond a predetermined limit causes the interlock to form a rigid outer wall preventing further compression. The pressure at which the inner core begins to compress and the percent of compression at which the outer wall locks is determined by their material composition, wall thickness and pre-compression during manufacturing.

Abstract: A method and apparatus for acquiring acoustical data from a borehole and is especially useful in carrying out tomogrphy surveys. The borehole digital geophone (BDG) tool of the present invention is capable of operating from a standard, 7-conductor logging cable with no special cables being required since the individual digital geophone modules (DGM) which form the BDG tool are connected together by short, separate lengths of the same 7-conductor cable. Each DGM acquires, digitizes, stacks, and stores data generated by its own three-component geophone assembly prior to transmitting these signals to the surface over a dedicated conductor in the cable thereby substantially increasing the sample rate of the tool which, in turn, substantially reduces the field time to run a tomography survey.

Abstract: An apparatus for supplying the power requirements of an Ocean Bottom Seismometer is disclosed wherein the power supply is separate from the power consuming devices of an Ocean Bottom Seismometer and mounted on the weight holding the Ocean Bottom Seismometer on the ocean floor during recording.

Abstract: In a well logging system that is subjected to high temperatures and pressures, an improved thermos flask pressure housing is used to insulate sensitive electronic circuits to the detrimental effects of high temperature and extreme pressure. An evacuated area between an inner shell and an outer shell acts as insulation between electronic circuits within such inner shell and the borehole environment surrounding such outer shell.

Abstract: A method and apparatus for retrieving an ocean bottom seismometer deployed to a subsea location is disclosed wherein inflatable flexible housings are attached to cylindrical cannisters having detecting and recording equipment along with identical inflation apparatus.

Abstract: An interlock system is provided wherein access to a test area containing radioactive material is prevented when testing is initiated and generation of harmful rays is prevented when access to the test area is gained during tests.