Abstract: A connector 10 is disclosed which is suited for use in effecting an electrical connection between separate conductor bundles 12, 16 in adjacent sections of a threadably sectioned conduit. The connector 10 is especially well suited for use in providing electrical continuity across a tool joint in a drill string. The connector 10 has first and second portions 20, 22 each adapted for placement in a corresponding connection portion of two connectable lengths of conduit. The first and second portions 20, 22 form a pin and box connection. Corresponding contacts 46, 80 on the first and second portions 20, 22 assume a conductive relationship in response to connection of the conduit. The contacts 46, 80 of each connector portion 20, 22 are radially symmetric about the axis of the conduit and are axially displaced one from the other. The contacts 46, 80 within the assembled connector 10 are isolated from the conduit environment.

Abstract: A hollow tubular member, such as a drill string member (15, 16), stuck by differential pressure against the side wall of a wellbore (10), is released by measuring (21) the temperature distribution around the circumference of the member, determining from this measurement the side which is stuck (17), and then perforating (22) the member at the stuck side to flow fluid into the formation and equalize the pressure behind the stuck portion of the member.

Abstract: Apparatus for downhole storage of an electrical conductor within a drill string in a borehole. The conductor is stored as a coil in a flexible storage means. The apparatus is desirably used to eliminate the short lengths of cable and the associated connectors which are normally added with each new section of drill pipe added to the drill string. Because the device is flexible, it may be used in deviated drilling.

Abstract: A self-locking cable connector especially useful in wireline data telemetry operations or wellbore logging comprises a plug and receptacle. A locking sleeve assembly acts to lock a key on the plug into a circumferential keyway on the receptacle, when the plug is inserted into the receptacle to form an electrical connection. Seals keep the connectors isolated from the drilling fluid which is circulated during rotary drilling. The cable connector may pass through rig sheaves and may be spooled with the cable.

Abstract: An improved apparatus to store an insulated electrical conductor cable in a overlapped configuration within a drill pipe includes a track attached to the drill pipe to guide a lower cable guide so that the overlapped portions of conductor cable will not snarl or twist during rotary drilling operations. To insure against entanglement, further restriction of rotation may be gained by additionally tracking the lower cable guide on a tensioned portion of the conductor cable which extends from a subsurface instrument package upwardly to an upper cable guide. A method for installing this improved apparatus is also disclosed.

Abstract: Abnormal drilling conditions are detected by monitoring mud volume of the mud system or rate of change of the mud volume. In one embodiment, makeup mud is automatically added to the system as solids are removed from the mud. Abnormal conditions are indicated by when the rate of makeup mud addition differs from the rate of solids removal. The mud system is maintained at a substantially constant volume by means of tanks specially constructed to provide a small mud/air interface.

Abstract: An insulated electric conductor employed in a tubular drill string to transmit electric energy between subsurface and surface locations is arranged within the drill string in a convoluted configuration to provide an excess length of conductor. The convoluted conductor is prevented from entangling during drilling by rotation limiting assemblies mounted in the drill string over a selected interval.

Abstract: A cable system for wellbore telemetry includes a cable anchored at a subsurface location in a rotary drill string, guide assemblies for maintaining the cable in a looped configuration, and a cable gripping device for maintaining a portion of the cable in tension. Preferably the cable is provided with a novel releasable connector and latch assembly which (1) permits the cable to be electrically connected to a subsurface instrument and anchored to the drill string, (2) permits the cable to be maintained in tension, and (3) is releasable by manipulation of the cable at the surface.