Abstract: Information on tooth wear is obtained from the frequency distribution spectrum of a vibrational quantity influenced by the impact of cutter teeth on the bottom of a bore. For example, spectra may be obtained from the product of signals indicative of torque and torsional acceleration. Tooth wear is then indicated by the shift upwardly in frequency of peaks in the spectra. Other quantities which may be used, singly or together to enhance spectral information, are weight on bit, vertical acceleration, transverse acceleration, standpipe pressure. Abrupt changes in frequency distribution curves indicate abrupt occurrences such as broken teeth or stuck cones. A stuck cone is also indicated by unidirectional peaks in a plot of torsional acceleration against time.

Abstract: A well-logging laboratory, for use with a well-logging tool which is suspended within a borehole by a wireline, includes a moveable frame upon which the wireless drum is mounted, and a moveable bulkhead is associated with the frame and various well-logging apparatus can be secured to the bulkhead, whereby the frame and bulkhead may be assembled as a modular unit, and moved within the well-logging laboratory as a modular unit.

Abstract: The invention relates to a tool having a valve (3c, 4c) for closing the tubing (100) of a well into which the tool has been placed. The valve member (4c) is controlled by means of a traction cable (17) via a hydraulic mechanism having two piston-and-cylinder assemblies (4b, 5e, 45; 1g, 4a, 41) which reduce the force applied on the valve member (4c) by the pressure of the fluid in the well and which amplify the force (f) applied thereto by the cable (17) in order to open said valve member.

Abstract: The invention relates to a tool suitable for closing a production column (100) of a well when the tool is located in a connector of enlarged diameter (101). The tool is lowered on the end of a cable (76) and includes a tilting valve member (60) which is oblong in shape and which is oriented longitudinally to pass through the corresponding oblong orifice of a valve seat (69) fixed to the connector, and is then oriented transversely in order to co-operate with said seat in order to close the production column when a traction force (F) is applied to the cable (76).

Abstract: A well logging sonde is disclosed which includes a collimating window design for the accurate detection of gamma rays of low and high energy which are back-scattered from a region near a source of gamma rays emitted into the formation. The sonde includes a tungsten support inner tube or shell surrounded by a length of "U" shaped steel. A conduit is formed in the wall of the shell at an angle with respect to its axis and is oriented symmetrically toward the opening of the "U" shaped steel support member. A closing member of a thin layer of titanium is welded to the open ends of the "U" shaped steel member. An arcuate tungsten pad is secured about the titanium closing member and partially about the exterior of the open ends of the "U" shaped steel support member. A conduit in the pad is aligned with the conduit of the inner shell to form a collimating window. A gamma ray detector of a length shorter than the "U" shaped steel section is mounted within the inner tube in the path of the collimating window.