Abstract: The present invention is a sheave assembly that includes a ring supported by a support assembly instead of a solid sheave wheel supported by a central axle. The support assembly may include a plurality of rollers or a curved shoe. The ring is made of a lubricated plastic material or other similar material. The ring includes a groove for retaining the wireline or cable and an inner surface that is designed to mate with the outer surface support assembly.

Abstract: A gas detection method includes carrying out respective neutron and density logs, using neutron and density detectors, along a length of well. The density log is corrected for the dimensions and properties of the well casing. The corrected density log is then combined with the neutron log to compensate for regions of artificially high density outside the casing. The compensated density log is continuously calibrated against the neutron log. The dynamically calibrated density and neutron logs are inspected for crossovers that signify the presence of gas in a formation.

Abstract: The apparatus includes a pump for circulating pressurized fluid in a wellbore. A control device controls the pump which a conduit interconnects to the wellbore. A downhole transducer detects changes in fluid pressure at a downhole location and generates signals accordingly. A processor generates actuator commands based on the signals. Actuators activate a downhole tool based on the actuator command. A modulating valve modulates the fluid pressure. A remote transducer detects the pressure remotely from the downhole transducer. The control device causes the pump to generate acoustic signals in the fluid via wave forms which the downhole transducer detects. The modulating valve generates wave forms in the fluid. The control device sends control signals via the fluid to the downhole transducer. Consequently the processor actuates the tools. Following correct actuation the modulating valve generates signals via pressure changes which the remote transducer receives to indicate successful tool deployment.

Abstract: In the field of wellbore data logging it is known to use isotopic neutron sources in a neutron capture logging technique. However, continuous isotopic sources are unpopular for regulatory and safety reasons. Attempts to employ neutron generator tubes to generate neutron bursts for use in the neutron capture technique have encountered various difficulties in areas connected with signal identification and processing. The disclosure relates to a method of data logging in which a low burst rate neutron generator tube is pulsed at comparatively low rates to generate neutron bursts that are captured in atomic nuclei in a proximal formation. The gamma radiation arising from the neutron capture is detected over a gating intervals defined by temporally distinct points. The gamma detector output is integrated over the gating interval to provide a measure of the decay rate that is independent of the pulse rate. Consequently the signal processing problems do not arise.

Abstract: A connector that includes a male connector assembly having a nose portion that removably fits within an axial cavity in a female connector assembly and which has removable, replaceable contacts. The connector assemblies are constructed for attachment to equipment and instrumentation in wet or dry environments. Each connector assembly may include a plurality of conductors that are constructed for attachment to conductors in the equipment and instrumentation. Each conductor in the male connector assembly is matched with a conductor in the female connector assembly for transmission of a signal therethrough. Electrical contacts within the connector assemblies provide individual contact of the matching conductors. Insulators separate and insulate the electrical contacts from one another.

Abstract: A method of compensating a density log comprises the step of compensating the far density by adding a correction at a given point in the density log wherein: (a) the correction comprises at least a first correction function and optionally a second correction function; (b) when the correction includes both the first and second correction functions they respectively are corrections for “slow-moving” and “fast-moving” perturbations at the said given point; and (c) regardless of whether the correction includes the second correction function the first correction is filtered by a long filter.

Abstract: A gas detection method includes carrying out respective neutron and density logs, using neutron and density detectors, along a length of well. The density log is corrected for the dimensions and properties of the well casing. The corrected density log is then combined with the neutron log to compensate for regions of artificially high density outside the casing. The compensated density log is continuously calibrated against the neutron log. The dynamically calibrated density and neutron logs are inspected for crossovers that signify the presence of gas in a formation.

Abstract: A drillpipe sub (30) comprises a shaft (32), a first frustoconical member (34) encircling, and fixedly mounted on, the shaft (32), and a second, opposed frustoconical member (36) encircling, and slidably mounted on, the shaft (32). The first frustoconical member (34) is bonded at its base (38) to the base (40) of the second frustoconical member (36).

Abstract: An apparatus and method for deploying a so-called compact battery/memory logging tool, for acquiring data in deviated or horizontal wells in the oil and gas well data logging industry. A drillpipe assembly (10) includes a drillpipe (11) having secured at a downhole end thereof a delatching latching sub (12) containing an extendable running sub (13) supporting a battery/memory logging tool (14). The running sub (13) occupies an initial, retracted position during deployment of the drillpipe (11), whereby the logging tool (14) is protected within one or more drillpipe stands. The running sub is movable by a messenger (26) to a second, extended position in which its logging tool (14) protruding from the drillpipe (11). The drillpipe assembly may therefore be used to protect the logging tool (14) during running in operations; and then to extend the logging tool permit commencement of logging operations.

Abstract: A method, of logging a borehole, for use in a cased oil well for detecting the gas/oil or water/oil contact in a hydrocarbon reservoir, using a neutron capture technique to detect one or more properties of fluid includes comparing the count rates from two or more radiation detectors spaced at respective first and second distances from an isotopic source of continuous neutron radiation. The contact detection criteria are arranged to be substantially independent of borehole fluid characteristics. Apparatus (10) for carrying out the method includes a logging tool (10) having an isotopic source (16) and two spaced detectors (17,18).

Abstract: A method of well logging in which the logging tool is delivered to the bottom of the well within a drill pipe and then the well is logged by withdrawing the drill pipe with the sensor portion of the logging tool protruding from the drill pipe. Following the logging operation, the logging tool is returned to the surface by reverse circulation.

Abstract: A self contained logging tool comprising electronic apparatus for logging a well is disclosed. This tool includes a normally open fluid flow valve structure being activated to operation by differential movement of drill pipe in which the logging tool resides. The valve structure operates to gradually close and thereby restrict the flow of fluid through the valve, which in turn restricts the flow of fluid within the drill pipe. This flow restriction results in increasing the back pressure within drill pipe to provide an indication at the surface that the logging tool is struck.

Abstract: A well logging method and apparatus is described, which enables well logging to be conducted while still allowing passage of fluid mud within the well to maintain well control.

Abstract: A small diameter tool for measurement of resistivity of geological rock formations, including a complex auxiliary electrode structure which is adjustable in electrode length between deep and shallow mode measurement operations.

Abstract: A method of well logging in which the logging tool is delivered to the bottom of the well within a drill pipe and then the well is logged by withdrawing the drill pipe with the sensor portion of the logging tool protruding from the drill pipe. Following the logging operation, the logging tool is returned to the surface by reverse circulation.

Abstract: A cable stringing block assembly is disclosed having a frame and axle assembly configured to hold a non-conducting sheave wheel. The sheave wheel is fabricated of a durable polymeric material. In one embodiment, the sheave wheel is self-lubricating, having a coefficient of friction less than 0.5. A handle is optionally affixed to the frame structure to facilitate transport of the block assembly. In another embodiment, a spring-biased fly gate facilitates side-loading of the cable. A helicopter arm can also be provided for helicopter loading of the cable. The cast aluminum frame can be anodized to disguise its appearance from scrap aluminum thieves and provide additional weather protection.

Abstract: A conduit cable feeding sheave assembly is disclosed having a frame structure, an axle assembly disposed within the frame structure, and a sheave wheel disposed about the axle assembly. In one embodiment, the sheave wheel is fabricated of a self-lubricating, durable polymeric material. A slotted, tubular arm affixed to the frame extends along a line substantially tangential to the wheel. The arm has an exterior diameter sized to fit within a conventional conduit pipe, preferably having a diameter ranging from 2 to 10 inches. In one preferred embodiment, the tubular arm has at least one locking mechanism for temporarily securing the conduit sheave assembly within the conduit pipe. One disclosed locking mechanism is a threaded screw that extends from the interior of the tubular arm to engage the conduit.

Abstract: The well logging tool comprises differential valve means allowing passage of fluid through said tool during logging operations on when the tool becomes jammed inside a drillpipe.

Abstract: A well logging device of compact reduced diameter compared to the prior art, such well logging device having both short spaced and long spaced types of gamma ray crystal detectors installed in a measurements skid that comprises a relatively small diameter device constructed to withstand high temperatures and pressures, this device comprising a continuous stainless steel tube which provides pressure resistance and also allows low energy gamma ray transparency via large and small windows. This elongate type of stainless steel skid tube is furthermore internally supported by an internal tungsten tube placed therewithin, while the skid design also includes means for pressing the skid tube against a borehole wall so as to obtain more accurate formation density measurements downhole.

Abstract: A stuffing box sheave assembly includes a brace having a tubular collar positioned at one end and a pair of spaced apart forked arms outwardly projecting from the opposing end. A nylon wheel is rotatably mounted between the forked arms. The wheel has an annular grooved recessed around the circumference thereof. The groove is configured to receive a wireline. An arcuate shroud is positioned over a portion of the circumference of the wheel. A pair of spaced apart retention pads are mounted to the shroud. Each of the pads are configured to be received within the groove of the wheel so as to prevent accidental jumping of the wireline out of the groove. A pair of tubular posts project from opposing sides of the shroud and are selectively received within the channel of a tubular member upwardly projecting from each forked arm.