Abstract: A sensing apparatus is provided for use downhole, comprising a housing and sensing means with the housing containing a plurality of separable elements to which data acquired by the sensing means is transferred. The separable elements are releasable from the housing to convey the acquired data to surface. The separable elements have a spherical outer casing of around 1 to 10 cm diameter which surrounds a memory chip. The casing has a sealable aperture so that electrical connection to the chip can be established within the housing.

Abstract: A survey tool for use in a wellbore includes a downhole portion having an axis. The downhole portion is adapted to move within the wellbore with the axis generally parallel to the wellbore. The survey tool further includes a first acceleration sensor mounted at a first position within the downhole portion. The first acceleration sensor is adapted to generate a first signal indicative of an acceleration of the first acceleration sensor along the axis. The survey tool further includes a second acceleration sensor mounted at a second position within the downhole portion. The second position is spaced from the first position by a non-zero distance along the axis. The second acceleration sensor is adapted to generate a second signal indicative of an acceleration of the second acceleration sensor along the axis.

Abstract: An apparatus and a method for controlling oilfield production to improve efficiency includes a remote sensing unit that is placed within a subsurface formation, an antenna structure for transmitting power and communicating signals to the remote sensing unit and for receiving communication signals from the remote sensor, a casing joint having nonconductive “windows” for allowing an internally located antenna to communicate with the remote sensing unit for those embodiments in which a wireline tool is being used to communicate with remote sensing unit, and a system for obtaining subsurface formation data and for producing the formation data to a central location for subsequent analysis. The remote sensing unit is a standalone sensor that is placed sufficiently far from the wellbore to reduce or eliminate effects that the wellbore might have on formation data samples taken by the remote sensing unit.

Abstract: A method of determining an in situ PVT property of a hydrocarbon reservoir fluid that is present in a hydrocarbon-bearing formation layer traversed by a borehole, which method involves the steps of: a) calculating along the hydrocarbon-bearing formation layer the pressure gradient; and b) determining the in situ PVT property from the pressure gradient using an empirical relation that had been obtained by fitting a curve (11) through previously obtained data points (12, 13, 14) having the measured PVT property as a function of the pressure gradient.

Abstract: The present invention provides a tool assembly for use in field applications to monitor at least one condition in a well or other hole. The tool assembly may include a computing unit for directing operation of the tool assembly and may be sized to be operable in a hole having a diameter of 1 inch, and in some cases even smaller. In one aspect, the tool assembly is designed to significantly conserve power. Sensor readings may be taken at different schedules to conserve power when frequent readings are not required. Also, internal electronics of the tool assembly can be operated at a low voltage. In one aspect, the tool assembly is assemblable by simple rotatable engagement of the components, with electrical interconnections being made automatically by the rotatable engagement without keying of components. In another aspect, the tool assembly is networkable with other like tool assemblies and monitorable from a central location.

Abstract: In accordance with a method of this invention, formation integrity problems are discovered, diagnosed and corrected in successively drilled subterranean well bore intervals. If one or more of well bore fluid outflows, formation fluid inflows or inadequate well bore pressure containment integrity are discovered in a drilled well bore interval, well logs are run and other relevant well bore data is collected in the drilled well bore interval and analyzed to provide a specific treatment using a specific pumpable sealing composition for sealing and increasing the pressure containment integrity of the well bore. Thereafter, the sealing composition is pumped into the drilled well bore interval whereby the well bore interval is sealed or the pressure containment integrity is increased, or both.

Abstract: A borehole device having proximal and distal ends comprises an enclosure at the proximal end for accepting an aircraft cable containing a plurality of insulated conductors from a remote position. A water sensing enclosure is sealingly attached to the enclosure and contains means for detecting water, and sending a signal on the cable to the remote position indicating water has been detected. A bottom sensing enclosure is sealingly attached to the water sensing enclosure for determining when the borehole device encounters borehole bottom and sends a signal on the cable to the remote position indicating that borehole bottom has been encountered.

Abstract: A tubing conveyed casing collar locator system that detects the casing collars in a wellbore and acoustically transmits the information through the tubing to the surface where it is detected and processed in a surface processor. The system comprises a downhole tool which comprises downhole sensors, a signal processor with memory, a drive circuit, a battery pack, and a signal generator. The surface system comprises a surface processor, depth system, and acoustic signal transmitter/receiver. The downhole tool detects casing collars as the tool is moved through the collar and acoustically transmits the data or stores the data in downhole memory according to programmed instructions. In one embodiment, the tool compares sensor signals from production elements, such as valves, to stored sensor signatures to uniquely identify the downhole element. In one embodiment, the downhole tool changes operating modes in response to surface command.

Abstract: The invention relates to a device for measuring lateral displacement of a casing in a vertical bore and includes an inclinometer probe, a cable, and a cable reel with electronics mounted in the reel hub. The probe contains two servo-accelerometers, a microprocessor and an electrical circuit. The servo-accelerometers provide analog signals that indicate the inclination angle of the vertical bore hole. The electrical circuit converts the analog signal from each servo-accelerometers to a digital signal which is read by the microprocessor. The microprocessor analyses the data and transmits the digital encoded data over a twisted-pair cable to a digital display unit connected to the cable reel hub. DC power for the probe is provided by the electronics in the reel hub over the same twisted-pair cable.

Abstract: A gyroscope that may include various sources of error, with those sources of error each being dependent upon a different parameter, is associated with a simulation or “model” of the gyroscope which is typically a computer simulation. The computer simulation is provided with errors which can be adjusted to be identical with the errors present in the real gyroscope. An arrangement is provided to adjust the errors in the model of the gyroscope to be identical with the errors in the real gyroscope, that arrangement including Kalman filters which receive signals generated by subtracting the outputs of the real gyroscope and the model gyroscope, while simultaneously varying the various inputs to the real gyroscope. The Kalman filters also generate a signal which is an estimate of the angular rotation being sensed by the real gyroscope.

Abstract: A method of designing a hydraulic fracturing treatment in a subterranean reservoir comprising the steps of a) quantifying reservoir parameters including the bottomhole temperature and the formation permeability, b) assessing the temporary variation in temperature of the formation due to the injection of a treatment fluid and c) designing a fluid optimized for said temporary temperature.

Abstract: The present invention discloses an acoustic resonator device capable of nucleating bubbles in a formation fluid under borehole-like conditions wherein the static pressure is higher than the bubble point pressure. The device is comprised of one or more coaxial layers forming a central conduit, wherein at least one of the coaxial layers is comprised of an electro-acoustic transducer material such as including piezoelectric or magnetorestrictive materials. This device is preferably designed to be in fluid communication with a host tool to allow in-situ sampling and bubble point determination. Also disclosed is an in-situ method of fluid analysis in a borehole for determining phase characteristics of a formation fluid using the device. Cavitation may be induced using the device in either a captured volume sample or a flow-line sample.

Abstract: The invention is directed toward a subsurface gravity measurement device and a method for calibrating the same that includes a tilt meter and a gravity sensor. The method includes associating tilt information produced by the gravity sensor as a function of a relationship between tilt information produced by the tilt meter and a correction parameter. The tilt meter produces tilt data, and the gravity meter produces gravity data, corresponding to the tilt data. The tilt data and gravity data is fitted to a polynomial equation that has a plurality of initial coefficients associated therewith. The initial coefficients includes information concerning the correction parameter. The correction parameter is derived as a function of the initial coefficients.

Abstract: A method for collecting data regarding a matric potential of a media includes providing a tensiometer having a stainless steel tensiometer casing, the stainless steel tensiometer casing comprising a tip portion which includes a wetted porous stainless steel membrane through which a matric potential of a media is sensed; driving the tensiometer into the media using an insertion tube comprising a plurality of probe casing which are selectively coupled to form the insertion tube as the tensiometer is progressively driven deeper into the media, wherein the wetted porous stainless steel membrane is in contact with the media; and sensing the matric potential the media exerts on the wetted porous stainless steel membrane by a pressure sensor in fluid hydraulic connection with the porous stainless steel membrane. A tensiometer includes a stainless steel casing.

Abstract: A method and apparatus is disclosed for improving the accuracy of directional surveys using magnetometers and accelerometers. The method corrects errors in bias, scale-factor, misalignment of cross-axial magnetometers, and bias or scale-factor of axial magnetometer by requiring the magnitude of measured cross-axial magnetic field to be as constant as possible over several tool face angles at a survey point in a wellbore and the magnitude of the measured total magnetic field and dip angle equal to the reference values, respectively. The axial component of the measured magnetic field is also determined. The method also corrects accelerometers similarly. The calibration parameters obtained at one survey point are applied to measurements at other survey points to improve the accuracy of surveys and the efficiency of drilling operations.

Abstract: The present invention discloses a method and apparatus to detect bubbles in a fluid sample to determine if gases are present, wherein an ultrasonic source is used and its properties monitored. Fluctuations in the ultrasonic source's electrical properties indicate the presence of bubbles/gas. Alternatively, the ultrasonic source may be used to cavitate the sample and induce the nucleation of bubbles. In such a system/method, bubbles may be detected by either (1) monitoring the ultrasonic source properties, (2) monitoring the compressibility of the sample, (3) monitoring the sample properties, including harmonics and subharmonics. The method and apparatus disclosed herein may be used in a borehole such as with a sampling means (including either a flowing sample or a stationary sample) or in a surface lab.

Abstract: A method of measuring resistivity values in relation to the azimuthal displacement of a measurement sensor displayed on a measurement-while-drilling device in a wellbore environment is disclosed. The present invention also provides an instantaneous reading of resistivity values. A resistivity sensor measures a volume having a circular cross-section, and whose center is the geometric center of the tool. Averaging removes measurement errors, such as those due to tool motion. Information on the formation resistivity is obtained as a function of the location of the center of the tool. A method of acoustic standoff determines offset of the drill tool and distances to walls. The operator gains knowledge of bedding layer formation and dip from azimuthal dependence of standoff and resistivity values.

Abstract: Compositions and methods for tracking the transport of particulate solids during the production of hydrocarbons from a subterranean formation.

Abstract: An apparatus and a method for controlling oilfield production to improve efficiency includes a remote sensing unit that is placed within a subsurface formation, an antenna structure for transmitting power and communicating signals to the remote sensing unit and for receiving communication signals from the remote sensor, a casing joint having nonconductive “windows” for allowing an internally located antenna to communicate with the remote sensing unit for those embodiments in which a wireline tool is being used to communicate with remote sensing unit, and a system for obtaining subsurface formation data and for producing the formation data to a central location for subsequent analysis. The remote sensing unit is a standalone sensor that is placed sufficiently far from the wellbore to reduce or eliminate effects that the wellbore might have on formation data samples taken by the remote sensing unit. The subsurface formation data values are transmitted to a central location for analysis.

Abstract: Shifts in rock strata are measured be inserting into a bore hole in the rock a conductive tube in which an insulated conductor runs along the length and the continuity is measured between the conductor and the tube. When conductivity is detected, the shift in the strata amounts to the distance required for the tube wall to break the insulation and create an electrical content between the tube and the conductor.

Abstract: Wellbore survey methods and apparatus for wireline and measurement-while-drilling operations are disclosed which include a gyroscope, wherein the gyroscope has a spin axis, aligned with the instrument axis, and further having two sensitive axis orthogonally related to the spin axis and to each other. In addition, the wellbore survey apparatus contains a drive means, functionally connected with the gyroscope, to rotate the gyro about the instrument axis. The wellbore survey apparatus also contains a set of accelerometers, wherein the sensitive axis are aligned orthogonally to each other, and said drive means is functionally connected to the accelerometers to rotate the accelerometers about the instrument axis. Sensors determine the azimuthal direction of inclination of the wellbore at a first location therein and while traversing from said first location.

Abstract: Seismic waves are recorded twice by a reference sensor (8) above ground and by a sensor (18) located in the drill hole (1). Measurements are synchronized by a clock system, the clock associated with sensor (18) being designed specifically for providing such synchronization in spite of operating conditions prevailing at the bottom of a drill hole (vibrations, shocks, temperature).

Abstract: A gravity measuring apparatus is provided comprising a gravitational force detector including a test mass and which produces measurements related to gravitational force exerted on the test mass, characterized in that the gravitational force detector is adapted for use downhole and includes a compensator to compensate for errors in measurements made whilst downhole. The compensator may comprise a guide rail along which the gravitational force detector is moveable over a calibrated distance. Where the test mass is biased toward an equilibrium position about which measurements are made.

Abstract: A method and a device for detecting and localizing unwanted matter, e.g., cement deposits, internally in a drill string. A sleeve-shaped indicator body is dropped down through the drill string while the same occupies an operative position. Then, the indicator body lands either in a seat at the lower end of the drill string, or the indicator body becomes stuck within a pipe section at a higher level in the drill string. The drill string overlying the position of the indicator body may be considered free of deposits formed on the pipe section walls thereof, and these pipe sections thus may be re-used without any further examination or cleaning. If stuck at a higher level, the indicator body is subsequently localized at the surface through examination in context of disassembling the drill string. The indicator body also may comprise an indicator element that provides a detection signal or sign for its detection and localizing on the surface.

Abstract: An apparatus is provided comprising a first tubular having an inside surface and outside surface defining an outside diameter; a second tubular concentric with the first tubular, the second tubular having an inside surface defining an inside diameter greater than the outside diameter of the first tubular, an outside surface, and a longitudinal axis; a plurality of spacers between the first and second tubulars, each spacer having a longitudinal axis parallel to the longitudinal axis of the second tubular, wherein at least one spacer is hollow; and at least one data sensing device and/or at least one data collecting device and/or at least one data transmitting device is carried within the at least one hollow spacer.

Abstract: A method for assessing the fracture pressure closure is proposed. This method includes first injecting a fluid into the formation at a first generally constant rate Q to create a fracture, and then, dropping the pumping rate to significantly smaller feed rate q so that the volume of the fracture becomes constant, in other words. As the fracture volume becomes constant at equilibrium, the well is shut-in. The wellbore pressure is monitored and the closure pressure is determined from the analysis of the wellbore pressure using a time-function of the dimensionless “shut-in” time, defined as the ratio of time since shutting to pumping time. This method provides a way of estimating the friction component of the monitored wellbore pressure due to the fracture tortuosity and friction.

Abstract: For collecting data from a water well, down-hole sensors are housed in modules. The modules are arranged to be screwed together in-line to form a vertical string. Mechanically, the modules are secured to each other only by the screw connection. Data is transmitted to the surface on a 2-wire cable, there being no other electrical connection between the modules and the surface. The modules are connected in multi-drop configuration to the 2-wire cable. Data is transmitted using time-division multiplexing.

Abstract: A borehole probe and related method and apparatus that enables information related to the depth of the probe to be determined and utilized by the probe to perform tasks. The probe, comparing its sense of depth and other sensed physical and temporal information to pre-defined procedural and conditional constraints, causes a physical action to be performed, or signals another device, or signals the surface. Generally, the probe uses sensed benchmarks within the borehole that have an associated depth as a depth framework. Within the distances between the benchmarks, the probe uses inertial or other distance measuring devices to measure distance from the benchmarks. With accurate and constant knowledge of its own depth, the probe can perform tasks autonomously and at the correct depth.

Abstract: The invention is, in its various aspects, a method and apparatus useful for strapdown inertial navigation and surveying in a borehole. The method comprises maneuvering a probe including three vibrating mass, Coriolis effect gyroscopes in a borehole and initializing the probe's attitude in the borehole within the probe's frame of reference. Three orthogonal, incremental rotation angles and three orthogonal, incremental velocities are determined for the probe within the probe's frame of reference. The incremental rotation angles are determined from the gyroscopes. The method then translates the three incremental velocities from the probe's frame of reference into the inertial frame of reference using the three incremental rotation angles. Next, a velocity vector in a local-vertical, wander-azimuth frame of reference is determined from the translated incremental velocities. A velocity error observation is then obtained.

Abstract: The present invention provides systems utilizing fiber optics for monitoring downhole parameters and the operation and conditions of downhole tools. In one system fiber optics sensors are placed in the wellbore to make distributed measurements for determining the fluid parameters including temperature, pressure, fluid flow, fluid constituents and chemical properties. Optical spectrometric sensors are employed for monitoring chemical properties in the wellbore and at the surface for chemical injection systems. Fiber optic sensors are utilized to determine formation properties including resistivity and acoustic properties compensated for temperature effects. Fiber optic sensors are used to monitor the operation and condition of downhole devices including electrical submersible pumps and flow control devices. In one embodiment, a common fluid line is used to monitor downhole parameters and to operate hydraulically-operated devices.

Abstract: The present invention provides apparatus and method for evaluating the integrity of gravel packing. A screen is disposed in an annulus between the wellbore and a production tubing. A tubing, such as a wash pipe, is placed inside the production tubing to provide a fluid path for the gravel slurry for gravel packing the screen. A self-contained memory logging nuclear tool is located in the tubing below (downhole) the screen. After gravel packing, the tubing with the tool is retrieved from the well at a selected speed. The tool is activated to record data in the memory carried by the tool as it passes across the screen. The data stored in the memory is downloaded at the surface to produce a log which provides a measure of the integrity of gravel packing of the screen.

Abstract: A method and apparatus for testing blowout preventer systems that enables testing of various size pipe rams, as well as safe and efficient shut-in of a well, without having to trip the entire apparatus out of a well. The testing apparatus generally includes an upper elongated testing cylinder, an upper test seal assembly, a lower elongated testing cylinder, a lower test seal assembly and a test plug. Additionally, the testing apparatus may include a circulating flow assembly, a side-port assembly, and a check-valve assembly, all of which are axially connected in a series to allow the testing tool to be easily lowered into a riser to a subsea blowout preventer assembly. The subject invention permits testing of blowout preventers that are designed to seal around various size pipe diameters during a single pipe trip. The invention also allows the operator to efficiently and safely shut-in a well if a kick is experienced during testing operations.

Abstract: The present invention presents a method that effectively restores the real-time advantage of annular pressure while drilling (APWD) measurements taken during certain drilling operations that require the mud circulation pumps to be turned off (a “pumps-off” condition). APWD data, such as pressure measurements, is obtained from instruments and related electronics within the BHA. APWD data can be measured, stored and even processed in the BHA during a pumps-off condition for subsequent processing or communication of a reduced amount of data to the driller at the surface.

Abstract: There are many natural pauses during rotary drilling operations where a portion of the drill string remains stationary. Pauses include drill pipe connections, circulating time, and fishing operations. These pauses are used to obtain formation evaluation measurements that take a long time or that benefit from a quiet environment, as opposed to the naturally noisy drilling environment. Various techniques that are sensitive to the mud flow, weight-on-bit, or motion of the drill string may be used alone or in combination to identify the drilling mode and control the data acquisition sequence.

Abstract: An apparatus and method are provided for gathering data from a subsurface formation. A shell is utilized having a chamber therein, and being adapted for sustaining forcible propulsion into the subsurface formation. A data sensor is disposed within the chamber of the shell. The shell has a first port therein for communicating properties of a fluid present in the subsurface formation to the data sensor when the apparatus is positioned in the subsurface formation, whereby the data sensor senses at least one of the properties of the fluid.

Abstract: This disclosure describes a blended buoyancy oil well survey instrument capable of performing MWD measurements (measuring while drilling), where the well survey instrument is mounted. An oil well survey instrument in a closed cylindrical housing having a specific gravity greater than the drilling mud in which it is used is modified in buoyancy by attaching one of several identical elongate cylindrical hollow containers or cylinders to it. They are filled with light material. They are made sufficiently strong that they do not collapse at working pressures. The cylinders are provided with upper end and lower end threaded stub shafts and mating receptacles to thread together thereby providing a modified buoyant system. The method is concerned with adjustment of the buoyancy so that the rate of fall is modified; in conjunction with mud flow velocity in the drill string, the buoyant descent of the instrument is controlled to about 100 or 200 feet per minute.

Abstract: A specifically-reactive sample-collecting and testing device possessing a cavity or cavities each having a dimension small enough to enable sample liquid to be drawn into the cavity by capillary action, wherein a surface of the cavity carries an immobilized reagent appropriate to the test to be carried out in the device, and wherein said surface is a surface of a transparent solid plate to act as a light-transmissive waveguide and forming a wall of the cavity, said plate having an edge which is substantially optically smooth and transverse to the plane of the plate.