Abstract: A memory logging system for determining the status of a sliding sleeve valve disposed within the borehole. The sliding sleeve contains signal inducing devices. A logging tool is conveyed through the sliding sleeve and time intervals between sensor excursions induced by the sleeve's signal inducing devices are recorded and stored within the tool memory. These data are subsequently recovered when the tool is returned to the surface of the earth, and sensor excursion data are processed in a surface processor to ascertain relative axial positions of the sliding sleeve outer housing and the insert. The condition of the sliding sleeve is determined from these relative axial positions.

Abstract: Apparatus and methods for determining one or more fluid parameters of interest by irradiating fluid with a source of nuclear electromagnetic radiation and subsequently measuring attenuation and absorption properties of the fluid from which parameters of interest are determined. Measurements are made with a formation tester tool comprising preferably two functionally configured flow lines. The source simultaneously irradiates fluid contained in opposing irradiation sections that can be integral sections of each of the two flow lines. A radiation detector is dedicated to each irradiation section and measures radiation attenuation and absorption properties fluid contained within each flow line section. Absolute and relative fluid parameters of interest are determined from the responses of the two radiation detectors.

Abstract: A formation tester system with a tester tool comprising two or more functionally configured flow lines. The two or more functionally connected flow lines cooperating with one or more pumps and cooperating valves direct fluid to and from various axially disposed sections of the tester tool for analysis, sampling, and optionally ejection into the borehole or into the formation. The functionally connected flow lines extend contiguously through the sections of the tester tool. The functionally configured flow lines, cooperating with the one or more pumps and valves, can also direct fluid to and from various elements within a given tester tool section. Manipulation of fluid flows within the tester tool, as well as analysis, sampling and/or ejection operations, can be varied with the tester tool disposed in the borehole using appropriate commands from the surface of the earth.

Abstract: A system for measuring pressure in a well borehole using two pressure sensing gauges that are exposed to an area of common pressure. Pressure measurements are made with preferably two pressure gauge assemblies each containing a single pressure sensing gauge. The two pressure gauge assemblies are removably disposed within a receptacle or “pocket” in the outer surface of a wall of a formation tester tool section. When disposed or “side loaded” in the pocket, the gauges within the pair of assemblies are axially aligned and positioned in a plane that is normal to the radius of the formation tester tool section. Both pressure sensing gauges can be connected to respond to the same fluid pressure originating from a probe or port section of a formation tester tool. By disposing the pressure gauge assemblies in a receptacle or “pocket” in the outer surface or wall of a formation tester tool section, the pressure sensing gauges are exposed to wellbore fluids. Pressure sensing gauges are selected to have low mass.

Abstract: In an underbalanced drilling system and method, a change is induced in flowing bottom hole pressure in a wellbore. Data of the surface flow rate of effluent is then measured in response to the induced change. This measured data is obtained using a multi-phase flow meter before a separator of the underbalanced drilling system. Algorithms in computer software analyze the flowing bottomhole pressure and the measured surface flow rate data and determine both permeability and formation pressure for a portion of the wellbore in real-time during the underbalanced drilling operation. Ultimately, portion of the wellbore is characterized with the determined permeability and formation pressure.

Abstract: A system for steering the direction of a borehole advanced by cutting action of a rotary drill bit by periodically varying the rotation speed of the drill bit. The steering system comprises a motor disposed in a bent housing subsection and operationally connected to a drill string and to the drill bit. The rotation speed of the drill bit is periodically varied by periodic varying the rotation speed of the motor or by periodic varying the rotation speed of the drill string. Periodic bit speed rotation results in preferential cutting of material from a predetermined arc of the borehole wall which, in turn, resulting in borehole deviation. Both the drill string and the drill motor are rotated simultaneously during straight and deviated borehole drilling.

Abstract: Methods and apparatus for in situ, continuous, automatic, and real-time acoustic impedance calibration of a transducer in an acoustic logging system. By taking the frequency characteristics of the ultrasonic transducer which are present in the internal casing reflection and convolving them with the frequency characteristics of the casing being logged, a theoretical model is created with a theoretical acoustic impedance fluid producing a theoretical free pipe signal at each measure point. The measured signal is then compared to the theoretical free pipe signal thereby yielding a calibrated acoustic impedance value for at each measure point. The only model employed is in the theoretical calculation of spectrum characteristics of free pipe.

Abstract: A system for steering the direction of a borehole advanced by cutting action of a rotary drill bit by periodically varying action of a drill bit while continuously rotating a drill string to which the drill bit is operationally attached. The steering system comprises a bit perturbation device cooperating with a bent housing subsection and operationally connected to the drill string and to the drill bit. Drill bit action is varied by periodic varying the rotation speed or rate of penetration of the drill bit. Periodic drill bit action results in preferential cutting of material from a predetermined arc of the borehole wall which, in turn, resulting in borehole deviation.

Abstract: Methods and apparatus for determining the direction of borehole azimuthal offset and the borehole radius of curvature. Rotation rate of a borehole assembly is measured and mathematically converted into azimuthal torque imparted to the borehole assembly. Relative azimuthal offset is determined from variations in azimuthal torque over a rotation cycle of the borehole assembly. Relative radius of curvature is obtained from the magnitude of azimuthal torque over a rotation cycle. Relative azimuthal offset is converted to true azimuthal offset using an independent reference angle measurement. Relative borehole curvature is converted to true radius of curvature using a calibration constant determined in known borehole conditions.

Abstract: An analysis system, tool, and method for performing downhole fluid analysis, such as within a wellbore. The analysis system, tool, and method provide for a tool including a spectroscope for use in downhole fluid analysis which utilizes an adaptive optical element such as a Micro Mirror Array (MMA) and two distinct light channels and detectors to provide real-time scaling or normalization.

Abstract: A memory logging system for determining the status of a sliding sleeve valve disposed within the borehole. The sliding sleeve contains signal inducing devices. A logging tool is conveyed through the sliding sleeve and time intervals between sensor excursions induced by the sleeve's signal inducing devices are recorded and stored within the tool memory. These data are subsequently recovered when the tool is returned to the surface of the earth, and sensor excursion data are processed in a surface processor to ascertain relative axial positions of the sliding sleeve outer housing and the insert. The condition of the sliding sleeve is determined from these relative axial positions.

Abstract: Downhole drilling vibration analysis uses acceleration data measured in three orthogonal axes downhole while drilling to determine whether drilling assembly's efficiency has fallen to a point where the assembly needs to be pulled. In real or near real time, a downhole tool calculates impulse in at least one direction using the measured acceleration data over an acquisition period and determines whether the calculated impulse exceeds a predetermined acceleration threshold for the acquisition period. If the impulse exceeds the threshold, the tool pulses the impulse data to the surface where the calculated impulse is correlated to efficiency of the assembly as the drillstring is used to drill in real time. Based on the correlation, operators can determine whether to pull the assembly if excessive impulse occurs continuously over a predetermined penetration depth.

Abstract: A data reduction method for transmission of a borehole image to the surface of the earth using restricted band widths of LWD telemetry systems. The data reduction method is based on the measurement physics rather than mathematical compression algorithms. Measured data from a sensor are fitted, within the logging tool, to a response function relating sensor response to a parameter of interest. The coefficients of the fitted response function are scaled and then telemetered to the surface. The measured data are reconstructed at the surface by combining the telemetered coefficients with the response function. A borehole image is formed by combining reconstructed reduced data. Parameters of dipping beds intersecting the borehole can be determined from the coefficients.

Abstract: A borehole formation testing system that measures resistivity of near borehole formation in situ rather than the measuring resistivity of fluid drawn into a formation tester tool. A radially extendable probe assembly contacts and forms a hydraulic seal with the wall of a borehole using a pad. Electrode contacts are disposed on the contact surface of the pad and electrically contact the near borehole formation. Response of the electrode contacts are used to determine resistivity of the near borehole formation. This resistivity is with a deeper formation resistivity measurement to determine if virgin formation fluid is at or in the vicinity of the pad. Alternately, a plurality of resistivity measurements is made at the formation tester pad and virgin formation fluid at or near the pad is determined from the rate of change of the plurality of resistivity measurements.

Abstract: A monopole acoustic transmitter for logging-while-drilling comprising as a ring that comprises one or more piezoelectric arc segments. The ring is oriented in a plane whose normal is essentially coincident with the major axis of a logging tool in which it is disposed. The ring disposed within a recess on the outer surface of a short, cylindrical insert. The insert is inserted into a drill collar, rather than into the wall of the collar. The ring can comprise a continuous ring of piezoelectric material, or alternately arc segments or active ring segments of piezoelectric ceramic bonded to segments of other materials such as alumina to increase the frequency or heavy metals such as tungsten to reduce the frequency. The material and dimensions of the material used in-between the piezoelectric segments is chosen to alter the frequency of the ring.

Abstract: A gamma ray detector assembly for a borehole logging system that requires the measure of gamma radiation with optimized gamma ray energy resolution and with fast emission times required to obtain meaningful measurements in high radiation fields. The detector assembly comprises a lanthanum bromide (LaBr3) scintillation crystal and a digital spectrometer that cooperates with the crystal to maximize pulse processing throughput by digital filtering and digital pile-up inspection of the pulses. The detector assembly is capable of digital pulse measurement and digital pile-up inspection with dead-time less than 600 nanoseconds per event. Pulse height can be accurately measured (corrected for pile-up effects) for 2 pulses separated by as little as 150 nanoseconds. Although the invention is applicable to virtually any borehole logging methodology that uses the measure of gamma radiation in harsh borehole conditions, the invention is particularly applicable to carbon/oxygen logging.

Abstract: Methods and apparatus for determining the direction of borehole azimuthal offset and the borehole radius of curvature. Rotation rate of a borehole assembly is measured and mathematically converted into azimuthal torque imparted to the borehole assembly. Relative azimuthal offset is determined from variations in azimuthal torque over a rotation cycle of the borehole assembly. Relative radius of curvature is obtained from the magnitude of azimuthal torque over a rotation cycle. Relative azimuthal offset is converted to true azimuthal offset using an independent reference angle measurement. Relative borehole curvature is converted to true radius of curvature using a calibration constant determined in known borehole conditions.

Abstract: An electromagnetic well borehole telemetry system for transmitting information between a downhole transceiver, disposed preferably within a borehole assembly in the borehole, and a surface transceiver positioned at or near the surface of the earth. A trigger and cooperating strobe are used to define strobe increments. Synchronous telemetry measurements made during the strobe increments are algebraically summed to identify a synchronous cyclical noise component in a composite electromagnetic telemetry signal. Any non cyclical noise components occurring during the strobe increments algebraically cancel in the algebraic summing operation. The cyclical noise component is then removed from the composite signal thereby increasing the signal to noise ratio of the telemetry system. The system is particularly effective in minimizing electromagnetic noise generated by the rotation of a rotating element such as the rotary table or top drive of a drilling rig.

Abstract: A logging tool has three seismic sensors that generate seismic signals in response to microseismic events and can be a Triaxial Borehole Seismic system. The tool also has additional sensors, such as a wireline tension measuring circuit, a gamma ray sensor, an inclinometer, and a gyroscope. The tool deploys downhole with a multi-conductor (i.e., seven conductor) wireline. For the seismic signals, a telemetry unit on the tool derives frequency-modulated carrier signals from the seismic signals, and a transformer of the unit transmits these carrier signals to surface acquisition equipment using cross-wired pairs of conductors in the wireline connected to the transformer's terminals. For the signals from the other sensors, the telemetry unit derives analog carrier signals from their signals and transmits the analog carrier signals to the surface acquisition equipment using remaining conductors of the wireline.

Abstract: Disclosed herein are methods, systems, and devices for determining parameters of an earth formation. Pressure transient data from a formation test can be recorded and analyzed using an analytical model including one or more correction factors derived from an assumption that an induced flow within the formation is hemispherical. Regression analysis of the refined analytical model and the pressure transient data results in accurate earth formation parameters.