Abstract: An oil field tubular connection is provided for joining metallic tubulars at a well site. At least one end of each tubular is provided with a frustoconical external sealing surface for metal-to-metal sealing engagement with a corresponding surface of an adjoining tubular. A plurality of antigalling grooves provided along the external sealing surface each project radially inward thereof and circumferentially encircle the threaded end of the tubular member and seal the groove from fluid communication with the interior of the tubular member. The antigalling grooves are particularly well suited for use with a low angular taper sealing surface of less than approximately 7.degree., and reduce galling between the metal sealing surfaces during makeup of the connection. Each tubular connection may also include an energizing groove spaced axially between the exterior sealing surface and the threads on the tubular member.

Abstract: The box end of a threaded joint has an interior profile of an inwardly tapered threaded section, followed by a smooth sealing surface parallel to the longitudinal axis of the threaded joint, followed by an increased diameter seal ring groove, followed by an inwardly tapered smooth sealing surface. The pin end of the joint has an external torque shoulder, followed by an inwardly tapered threaded section, followed by a reduced diameter pipe dope reservoir, followed by an extrusion hump used to extrude a deformable seal ring used in the seal ring groove, followed by an inwardly tapered smooth sealing surface. When the threaded joint is fully made up, the entrapped seal ring has a primary metal-to-metal seal on its one side, formed by the mated smooth, tapered surfaces, and a secondary metal-to-metal seal formed by the extrusion hump and the surface above the seal ring groove.

Abstract: A conventional electromagnetic logging device, having both MWD and wire line embodiments, and having a pair of cutouts spaced along the length of the tool mandrel, each cutout having a length of greater than 4.0 inches as measured along the longitudinal axis of the tool, is modified by adding a pair of full metal jackets around the pair of cutouts. The first metal jacket placed around the first cutout in the mandrel has an additional cutout therein having a length in the range of 1.0 to 4.0 inches and a depth in the range of 0.25 to 1.0 inch. A transmitting antenna is placed in the cutout in the first metal jacket. The second metal jacket placed around the second cutout of the tool mandrel has a pair of spaced cutouts therein, each having a length in the range of 1.0 to 4.0 inches and a depth in the range of 0.25 to 1.0 inch. First and second electromagnetic receiving antennas are placed in the first and second cutouts in the second metal jacket, respectively.

Abstract: A downhole centralizer is provided for positioning along a drill pipe string passing through a deviated well bore. A centralizer body is connected to an upper sub by a plurality of lobe-shaped connectors which permit angular deviation of the central axis of the upper sub with respect to the central axis of the centralizer body. The centralizer body is preferably connected to a lower sub by similar lobe-shaped connectors. The opposite ends of each of the upper and lower subs are threaded for fixed engagement with respective upper and lower pipe joints in the tubular string. A flexible flow conduit is positioned within a passageway through the centralizer body, and a pair of upper and lower sealing member are provided to maintain sealed engagement between the respective upper and lower subs and the flow conduit for transmission of fluid through the centralizer.

Abstract: A drill string includes an anchor type set down bit threadedly connected to the deflection section. Threadably coupled above the deflector section is a shear and retrieve sub having three equally spaced latch pin receptacles and three equally spaced shear pin holes. Above the shear and retrieve sub is a beveled guide section for receiving a retrieving setting tool having a tapered end sized to be inserted within the beveled guide section. The shear and retrieve section has three equally spaced latch pin mechanisms and three equally spaced shear pins. A pickup cross over sub is coupled into the top of the shear and retrieve sub and has an enlarged diameter ring which acts to limit the downward movement of the shear and retrieve section within the interior of the beveled guide and retrieving setting tool sections. A drill string operating from the earth's surface is coupled into the pickup cross-over sub which allows the entire assembly to be lowered into an earth borehole to a desired depth.

Abstract: A hydraulic system and method are provided for supplying high pressure hydraulic fluid to a cylinder for operating a ram, e.g. a shearing and/or shut-off ram for a blowout preventer. It comprises means for supplying high pressure hydraulic fluid to the cylinder, said hydraulic fluid supply means comprising first and second storage means for storing hydraulic fluid under pressure, first conduit means for supplying hydraulic fluid under pressure from said first storage means to the cylinder, a pressure sensing device for determining the back pressure in said first conduit means, second conduit means for supplying hydraulic fluid under pressure from said second storage means to the cylinder and valve means for automatically opening said second conduit means when the back pressure in the first conduit means reaches a predetermined amount.

Abstract: Downhole measuring apparatus includes a gamma radiation source and at least two pairs of radiation detectors carried by a housing so that radiation may be emitted from the source and scattered by the environment of the housing and detected by the detectors. Each pair of detectors is arranged so that its detectors are positioned symmetrically on opposite sides of the longitudinal axis of the housing, and each pair of detectors, in combination with the radiation source, forms a different geometrical configuration so that, in general, the radiation counts obtained by the different pairs of detectors will not be redundant. The output signals from the detectors may be processed to provide data signals indicative of the radiation counts experienced by the detectors, and which may then be used to simultaneously obtain values for two or more downhole parameters. The addition of each new, independent pair of detectors permits the simultaneous solution of an additional downhole parameter.

Abstract: A rotary shear seal hydraulic valve which can be used in three- and four-way embodiments is formed by a housing and a body together defining therebetween a generally cylindrical stepped cavity in which a rotor is rotatably positioned. The housing contains at least two shear seal valve assemblies positioned to be aligned with ports in the rotor to establish communication between the shear seal means. The body contains at least one piston member including a rack portion engaging a profiled pinion portion of the rotor to effect the rotational drive of the rotor. The pistons can be driven in both directions by fluid means or in one direction by spring return means. The pistons can also be actuated by solenoid means and the positioning of the rotor can be strained by a lever providing a manual override. By selectively plugging the various ports, the four-way valve can be utilized in a three-way configuration, thereby providing a great degree of flexibility.

Abstract: A BOP subsea control system utilizes hydraulic control of non-critical functions, and electro-hydraulic control of selected critical functions, such as the closing mode of one or more shear ram BOPs, one or more pipe ram BOPs and one or more annular type BOPs. In an alternative embodiment, the use of a conductive fluid in a hydraulic hose enables electric signals and hydraulic signals to be transmitted in the same hose.

Abstract: A non-rotating drill string is formed from a plurality of independent, cylindrical sections pivotally connected together by a latch mechanism. The adjacent ends are partially beveled such that the sections can bend in a single direction. Means are disclosed for varying the effect of the beveled surfaces, thus controlling the angle of bend for a given one of the sections. A downhole mud motor (PDM) drives the drill bit through the use of a flexible drive shaft running through the center of a metal-lined, neoprene drilling fluid hose which runs through the interior of the independent cylindrical sections. The total curvature of the borehole drilled by the system equals the sum of the angles of bend between the individual sections.

Abstract: A method of calibrating a radiation detector, positioned in apparatus including a source of gamma radiation such that the detector may sense radiation from the environment of the apparatus due to radiation emitted by the source and scattered by the environment, includes utilizing test environments including formations of known bulk densities. The apparatus may be positioned within the test environments at different distances from the surfaces of the formations. Count rates of the detector are compared to the formation bulk densities for the distances of the apparatus from the formation surfaces to calibrate the detector relative to the radiation source.

Abstract: An accelerometer has a housing defining a chamber, and a magnetizable fluid 11 within the chamber. A permanent magnet is magnetically suspended within the chamber by the magnetizable fluid with its poles oriented along a displacement axis so as to be displaceable from a null position along the displacement axis by an applied force. At least parts of the outer surface of the permanent magnet in the vicinity of its poles are provided with non-magnetizable end members. A sensing arrangement is provided for detecting displacement of the permanent magnet along the displacement axis and for supplying an electrical signal indicative of the applied force. Such an accelerometer is relatively immune to calibration drift and has high measurement accuracy.