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: The invention refers to antenna configurations for electromagnetic logging tools. The antennas have one or more electrical conductors disposed on a dielectric substrate wrapped around a core or disposed directly on the core. The conductor or conductors are arranged such that the antenna has a first magnetic dipole moment substantially perpendicular to a longitudinal axis of the core. The invention also refers to antennas adapted for mutual balancing using interleaved conductive paths or disks to alter the magnetic dipole moments to mutually balance the antenna system.

Abstract: A unique means in interpreting anisotropic reservoirs in thinly laminated earth formations regardless of the hole deviation is provided. A high-resolution micro-resistivity formation measurement is used to estimate in real time at the well site the formation anisotropic electrical parameters oriented around the borehole drilled with a conductive fluid. Estimations of the formation anisotropy or hydrocarbon profile are compared and combined with indicators associated with the formation to provide improved evaluations of hydrocarbon content over conventional methods.

Abstract: Transverse or tilted magnetic dipole antenna systems are used for electromagnetic logging measurements to determine the anisotropic resistivity of subsurface formations. Combined measurements between transverse or tilted antennas, as well as axial antennas, are used to compensate for receiver antenna mismatch in the system. Some embodiments use model-based parametric inversion to estimate the anisotropic resistivity in the presence of invasion and shoulder-bed effects.

Abstract: The invention refers to antenna configurations for electromagnetic logging tools. The antennas have one or more electrical conductors disposed on a dielectric substrate wrapped around a core or disposed directly on the core. The conductor or conductors are arranged such that the antenna has a first magnetic dipole moment substantially perpendicular to a longitudinal axis of the core. The invention also refers to antennas adapted for mutual balancing using interleaved conductive paths or disks to alter the magnetic dipole moments to mutually balance the antenna system.

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 remote sensing unit for sensing subsurface formation is provided. The remote sensing unit is an active device with the capability of responding to control commands to determine subsurface formation characteristics, and transmitting corresponding data values. Some embodiments of the remote sensing unit include a battery, or a capacitor for storing charge. The embodiments that include the capacitor receive RF power that is converted to a DC signal for storing charge on the capacitor. When the charge is depleted to a specified point, the remote sensing unit prompts the wellbore tool to transmit additional RF power to recharge the capacitor. The remote sensing unit is provided with RF power to wake it up and to place it into an operational mode, and/or to send modulated data values that are then transmitted to the surface where operational decisions for the well may be made.

Abstract: A method and apparatus for collecting data downhole in a well bore, even during drilling operations, are disclosed. The apparatus generally comprises an antenna and some associated electronic circuitry. The antenna includes a plurality of arrayed transceiver elements and the electronic circuitry steers transmission or reception through the antenna by controlling the application of power to the array elements. In operation, a transceiver unit containing such an antenna is positioned proximate a remote sensor placed into a formation. An electromagnetic signal is then steered to communicate with the remote sensor over a wireless link.

Abstract: Systems and methods for monitoring a subsurface formation property and for placing a borehole in the vicinity of a well in the formation. A slotted tubular is utilized to provide through-tubular signal transmission and/or reception using an antenna adapted to generate a magnetic dipole moment with a transverse or controllable orientation. Hydraulic isolation between the interior and exterior of the tubular at the slot is provided by a pressure barrier. The tubular also forms part of a system for accurately placing a well within a desired distance and orientation relative to an existing well.

Abstract: Method and system for subsurface logging utilizing a modified metallic tubular having an elongated body with tubular walls and a central bore adapted to receive a support member. The tubular including slotted stations to provide through-tubular signal transmission and/or reception. Pressure barrier means provide hydraulic isolation at the slotted stations. The support member is equipped with various sources and sensors, including an antenna adapted to generate a magnetic dipole moment with a transverse or controllable orientation, and adapted for engagement within the tubular. The apparatus is suitable for LWT, LWD, and TLC logging operations.

Abstract: The method and apparatus of the invention determines earth formation resistivity at extended depths into the formation by the use of telemetry transmission signals to measure the formation resistivity. The telemetry transmission signals carry measurement data from downhole sensors through the formation to an uphole receiver. The signal transmission is by means of induction telemetry. At the receiver, the signal is demodulated to obtain the transmitted measurement data. During the detection of the signal at the receiver, the signal amplitude is also extracted and is used to determine the formation resistivity. In addition, changes in the signal amplitude are also used to indicate formation boundaries for determining well location during directional drilling.

Abstract: The present invention relates to a method and apparatus for establishing communication in a cased wellbore with a data sensor that has been remotely deployed, prior to the installation of casing in the wellbore, into a subsurface formation penetrated by the wellbore. Communication is established by installing an antenna in an opening in the casing wall. The present invention further relates to a method and apparatus for creating the casing wall opening, and then inserting the antenna in the opening in sealed relation with the casing wall. A data receiver is inserted into the cased wellbore for communicating with the data sensor via the antenna to receive formation data signals sensed and transmitted by the data sensor. Preferably, the location of the data sensor in the subsurface formation is identified prior to the installation of the antenna, so that the opening in the casing can be created proximate the data sensor.

Abstract: A method and apparatus for acquiring data representing formation parameters while drilling a wellbore is disclosed. A well is drilled with a drill string having a drill collar that is located above a drill bit. The drill collar includes a sonde section having transmitter/receiver electronics for transmitting a controlling signal having a frequency F and receiving data signals at a frequency 2F. The drill collar is adapted to embed one or more intelligent sensors into the formation laterally beyond the wall of the wellbore. The intelligent sensors have electronically dormant and active modes as commanded by the transmitter/receiver circuitry of the sonde and in the active mode have the capability for acquiring and storing selected formation data such as pressure, temperature, rock permeability, and the capability to transmit the stored data to the transmitter/receiver of the sonde for transmission thereby to surface equipment for processing and display to drilling personnel.

Abstract: A method and apparatus is disclosed for determining the properties of formations surrounding an earth borehole that have been invaded by borehole fluid to form an invaded zone.

Abstract: A well logging method and apparatus are disclosed for determining borehole corrected formation resistivity, borehole diameter, and downhole borehole fluid (mud) resistivity with improved accuracy. A logging device in the borehole transmits electromagnetic energy from a transmitter, which energy is received at receivers on the logging device. The phase and amplitude of the received energy are measured at the receivers and a phase shift, phase average, and attenuation are associated with the transmitter-to-receivers spacing. The process is then repeated for a plurality of further transmitters having different spacings from the receivers. A formation and borehole model having model values of borehole corrected formation resistivity, borehole diameter, and borehole fluid resistivity is generated.

Abstract: A logging apparatus is adapted to be disposed in a mud filled wellbore, and a measurement probe is connected to a bottom of a tool string of the logging apparatus. The measurement probe is adapted for measuring a resistivity of a mud in the mud filled wellbore. The measurement probe includes a bottom electrode disposed on a bottom of the probe when the logging apparatus is disposed in the wellbore, a second electrode, and at least one measurement electrode disposed adjacent the bottom electrode for measuring a voltage potential drop in a region of the mud which is disposed directly below the bottom electrode of the measurement probe when the probe is disposed in the wellbore. When the measurement probe is energized, a current flows in the mud between the bottom electrode and the second electrode.

Abstract: A new interpretation system receives a low resolution log and a high resolution log from a well logging tool that is disposed in a wellbore which traverses a highly laminated formation and generates an output record medium which clearly illustrates and quantifies each layer of the plurality of layers of the laminated formation. In response to receipt of the low and high resolution logs, the new interpretation system generates a rectangular deconvolved log. The rectangular deconvolved log is generated by first selecting a plurality of modes or possible formation types from a histogram. Each of the plurality of modes are then solved, in a least squares sense, by minimizing the sum, over a particular depth interval in the wellbore, of the square of the residual between the tool measurement and the reconstructed log, a calculation which is equivalent to solving a system of N equations and N unknowns.

Abstract: A logging method and apparatus for investigating the geometrical characteristics of a borehole comprises an array of circumferentially spaced apart azimuthal current electrodes (Aaz.sub.i) disposed on a sonde (21), and an annular current electrode (A) longitudinally spaced apart from the array of azimuthal electrodes. In a method of investigating the geometrical characteristics of the borehole, currents (Ic.sub.i) are emitted between the azimuthal electrodes and the annular electrode (A). Monitor electrodes (M, Maz.sub.i) are respectively associated with the current electrodes (A, Aaz.sub.i). The potential differences (Vc.sub.i) between annular monitor electrodes (MAz.sub.i) are detected. In response to the detected potential differences, output signals (Rc.sub.i) are generated indicative of the distances between the sonde and the wall of the borehole in a plurality of directions around the sonde.

Abstract: A spontaneous potential (SP) sub is interconnected between two metallic housings of a wellbore apparatus and is lowered into a wellbore. A spontaneous potential (SP) of an earth formation trasversed by the wellbore is measured by the SP sub, and a log is generated from the sub which is representative of the spontaneous potential of the formation, the log being substantially free of a special type of distortion which typified the prior art SP measurements taken by prior art SP measurement apparatus. The SP sub includes a measurement electrode, monitoring electrodes placed on both sides of the measurement electrode, a bucking electrode placed on both sides of the monitoring electrodes, current driving circuitry connected to the bucking electrodes, and receiving circuitry connected to the monitoring electrodes. The current driving circuitry delivers a current of sufficient magnitude to each bucking electrode such that the voltage potential between the monitoring electrodes is approximately equal to zero.