Abstract: A method for determining a position of a wireless electronic device within a volume includes detecting a signal transmitted by the wireless device during two-way communication to and from a first known position within the volume. The method further includes detecting the signal from at least three additional known positions within the volume, where the at least three additional known positions are spatially independent of each other. The method further includes determining a phase difference between the signal detected at the first position and the signal detected at each of the at least three additional positions, determining the position of the wireless electronic device using the phase differences, and at least one of displaying and storing the position of the wireless electronic device.

Abstract: A gas treatment unit includes an absorber, a liquid-jet ejector, a gas-liquid separator, a regenerator and a pump. A liquid outlet of the regenerator is connected to an inlet of the pump. An outlet of the pump is connected to a liquid inlet of the absorber. A liquid outlet of the absorber is connected to a liquid inlet of the jet-ejector. A regenerator gas outlet is connected to a gas inlet of the liquid-jet ejector. A liquid-gas outlet of the liquid-jet ejector is connected to an inlet of the separator. A liquid outlet of the separator is connected to a liquid inlet of the regenerator.

Abstract: A method of imaging the Earth's subsurface using passive seismic emissions includes detecting seismic signals originating from within the Earth's subsurface over a selected time period using an array of seismic sensors deployed proximate the Earth's surface. Hypocenters of seismic events in the subsurface are determined from the detected signals. Seismic signals detected at selected ones of the seismic sensors are cross-correlated to signals detected at other selected ones of the seismic sensors. The cross-correlated signals are processed to obtain a reflectivity series at a geodetic position of the selected one of the seismic sensors. A spatial distribution of at least one seismic property in the subsurface is determined using the determined hypocenters and the reflectivity series.

Abstract: A method for determining formation integrity during drilling of a wellbore includes determining an annulus fluid pressure in a wellbore during drilling thereof. The annulus pressure is adjusted by a predetermined amount. Flow rate of drilling fluid into the wellbore is compared to drilling fluid flow rate out of the wellbore. At least one of a formation pore pressure and a formation fracture pressure is determined from the annulus pressure when the compared flow rates differ by a selected amount. The method alternatively to determining pore and/or fracture pressure includes determining a response of the wellbore to the adjusted fluid pressure and determining the optimum annulus fluid pressure from the wellbore response.

Abstract: A method for seismic event mapping includes selecting a plurality of subvolumes representing possible locations of origin of a seismic event in the Earth's subsurface. For each subvolume a plurality of possible directions of motion of subsurface formations is selected. For each subvolume and each possible direction of motion, polarity correction is applied to seismic signals recorded at a plurality of positions proximate a volume of the Earth's subsurface to be evaluated. The polarity correction is based on the direction of motion and the position of each seismic sensor with respect to the subvolume. The recorded, polarity corrected seismic signal recordings are time aligned. The time aligned recordings are summed. A most likely direction of motion and subvolume position are determined based on a selected attribute of the summed, time aligned seismic signals.

Abstract: A method for estimating interval travel time of an Earth formation using an acoustic well logging instrument having a plurality of spaced apart acoustic transmitters and acoustic receivers includes measuring travel time between a transmitter and a receiver for substantially all possible combinations of each of the plurality of transmitters and each of the plurality of receivers. Each of the possible combinations includes a common depth interval of the Earth formations. The method then include determining at least one statistical measure of center of the measured travel times.

Abstract: A method for marine seismic surveying includes towing seismic sensors in a plurality of streamers in the water, actuating a seismic energy source in the water at selected times and detecting seismic signals at the sensors resulting from the actuation of the source. A data trace is created for each of the detected signals. At least one Fresnel zone is determined for at least some of the seismic data traces. A contribution of each of the traces to each one of a plurality of bins defined in a predetermined pattern is computed, based on the Fresnel zone associated with each trace. Based on the computed contributions, a maximum lateral distance between corresponding seismic sensors is determined that will result in a contribution sum above a selected threshold.

Abstract: A pushup exercise device includes a handle affixed to a handle base. The device includes a base plate. The handle base is rotatably supported on the base plate. A brake is disposed in the handle base and surrounds an extension on the base plate. The brake includes an adjuster disposed in the handle base to enable selection of resistance to rotation between the handle base and the base plate.

Abstract: A system for monitoring auxiliary operations on a drilling unit includes at least one sensor configured to measure a parameter related to a start time and a stop time of at least one auxiliary operation on the drilling unit. The system includes a data acquisition device configured to determine a start time and a stop time of the at least one auxiliary operation from measurements made by the at least one sensor. The data acquisition device includes a data recorder for recording elapsed time between the start time and the stop time.

Abstract: A marine electromagnetic sensor cable includes a plurality of sensor modules disposed at spaced apart locations along a cable. Each module includes at least one pair of electrodes associated with the module. The electrodes are arranged to measure electric field in a direction along the direction of the cable. The cable is arranged to form a closed pattern. Another marine electromagnetic sensor cable includes a plurality of sensor modules disposed at spaced apart locations along a cable. Each module includes at least one pair of electrodes associated therewith. The electrodes are arranged to measure electric field in a direction along the direction of the cable. A plurality of spaced apart magnetic field sensors is associated with each module and arranged to enable determining an electric field amplitude in a direction transverse to the direction of the cable from magnetic field gradient.

Abstract: A method for seismic surveying includes disposing a plurality of seismic sensors in a selected pattern above an area of the Earth's subsurface to be evaluated. A seismic energy source is repeatedly actuated proximate the seismic sensors. Signals generated by the seismic sensors, indexed in time with respect to each actuation of the seismic energy source are recorded. The recorded signals are processed to generate an image corresponding to at least one point in the subsurface. The processing includes stacking recordings from each sensor for a plurality of actuations of the source and beam steering a response of the seismic sensors such that the at least one point is equivalent to a focal point of a response of the plurality of sensors.

Abstract: A marine electromagnetic sensor cable includes a plurality of sensor modules disposed at spaced apart locations along a cable. Each module includes at least one pair of electrodes associated therewith. The electrodes are arranged to measure electric field in a direction along the direction of the cable. A plurality of spaced apart magnetic field sensors is associated with each module and arranged to enable determining an electric field amplitude in a direction transverse to the direction of the cable from magnetic field gradient.

Abstract: A method for determining position of a mobile electronic device includes emitting an acoustic pulse from the position of the mobile electronic device. The acoustic pulse is detected at a known position at three spaced apart locations along each of at least two lines extending in different directions. The range and phase difference of the acoustic pulse between each of the detecting locations is determined. A relative position of the device with respect to the known position is obtained from the range and phase differences.

Abstract: An anchor system for a tendon includes a load transfer device having at least one wedge receiving bore therein. The wedge receiving bore has a tapered interior surface. The anchor system also includes a wedge configured to be affixed to an exterior surface of a tendon. The wedge has a tapered exterior surface configured to cooperate with the tapered interior surface of the wedge receiving bore to laterally compress the wedge against a tendon when the wedge is moved longitudinally into the bore. Taper angle of the wedge and a taper angle of the wedge receiving bore are selected such that longitudinal compressive force exerted by the wedge is substantially evenly longitudinally distributed.

Abstract: An anchor for a post tension reinforcement is disclosed. The anchor includes an anchor base having at least one wedge receiving bore therein. The wedge receiving bore is tapered in diameter at a single selected taper angle. An axial length of the wedge receiving bore is selected so that a minimum internal diameter of the wedge receiving bore is at least as large as an external diameter of a sheath on a reinforcing tendon. In another aspect, the wedge receiving bore is positioned in the anchor so that its longitudinal center is approximately collocated with a load bearing basal surface of the anchor.

Abstract: A method for measuring magnetotelluric response of the Earth includes measuring transient controlled source electromagnetic response of the subsurface below a body of water over a plurality of actuations of an electromagnetic transmitter. The transient response measurements are stacked. The stacked transient responses are subtracted from measurements of total electromagnetic Earth response over a time period including the plurality of transient response measurements to generate the magnetotelluric response.

Abstract: A wedge for a tendon retaining anchor includes at least two circumferential wedge segments adapted to be placed on an exterior of a tendon. The wedge segments have an exterior surface adapted to cooperate with a receiving bore of a load transfer device and an interior surface having gripping elements thereon. A circumferential dimension of the wedge segments is selected so that a total uncompressed gap between circumferential ends of the wedge segments when the segments are applied to an exterior surface of the tendon is at most about 2.4 times a height of the gripping elements. In another aspect, a tendon retaining system includes an anchor having a wedge receiving bore and wedge segments adapted to cooperate with the wedge receiving bore. The wedge segments include gripping elements on an interior surface thereof. The system includes a device adapted to limit lateral compression of the wedge segments.

Abstract: A wellbore chemical treating system includes a pressure vessel for containing a treating chemical. The pressure vessel is closed to atmospheric pressure. A first controllably operated valve is disposed in fluid communication between an outlet of the pressure vessel and a well for selectively controlling the flow of the chemical from the pressure vessel to the well. A pressurized gas is disposed in the pressure vessel wherein the pressure exerted by the pressurized gas causes the chemical to flow from the pressure vessel to the well through the first valve when the first valve is opened. A second controllably operated valve is disposed in fluid communication between the well and an outlet of a fluid tank for selectively controlling flow of fluid in the tank to the well. The fluid tank is replenished by fluid produced from the well. The system includes a controller for selectively operating the first valve and the second valve.

Abstract: A centralizer includes two stop collars configured to be affixed to an exterior surface of a pipe. A plurality of circumferentially spaced apart spacers is each coupled at each end to one of the stop collars, a first plurality of circumferentially spaced apart bow springs is each coupled at one end thereof to the first stop collar and at an opposite end thereof to a first floating collar disposed between the first and second stop collars. A second plurality of circumferentially spaced apart bow springs is each coupled at one end thereof to the second stop collar and at an opposite end thereof to a second floating collar disposed between the first and second stop collars. A shape of the bow springs is selected to cooperatively engage the spacers and the floating collars such that when compressed the centralizer provides a substantially fluid-tight seal.

Abstract: A sensor cable system for measuring electromagnetic response of the Earth's subsurface includes a sensor cable deployable on the bottom of a body of water. The sensor cable has a plurality of electromagnetic sensing devices thereon at spaced apart locations. A system control unit is in signal communication with the sensing elements. The system control unit includes a transceiver for communicating signals to and from a corresponding sensor cable system. The system control unit includes a global positioning system signal receiver. The system control unit includes a processor configurable to receive signals detected by sensing elements in the corresponding sensor cable system. The processor is configurable to compute stacked signals from the sensing elements in the sensor cable and from sensing elements in the corresponding system. The processor is configurable to calculate a statistical measure of the stacked signals. The system control unit is disposed in a flotation device.