467 results about "Logging while drilling" patented technology

An electromagnetic wave propagation resistivity borehole logging system comprising multiple groups of electromagnetic transmitter-receiver arrays operating at three frequencies. The borehole logging tool component of the system employs eight transmitters and four receivers. The transmitters and receivers are disposed axially and symmetrically along the major axis of the tool to form four group pairs. Each group pair consists of a transmitter-receiver groups axially and symmetrically on opposing sides of a reference point on the tool. Each, transmitter-receiver group consists of one transmitter assembly and two receiver assemblies. Each transmitter-receiver group is operated at two of three operating frequencies which are 100 kHz, 400 kHz and 2 MHz. Some of the transmitter and receiver assemblies are fabricated to yield azimuthally focused resistivity measurements, and to yield vertical and horizontal resistivity in anisotropic dipping beds. The system can be embodied as a logging-while-drilling system or as a wireline logging system.

The present disclosure relates to dynamically incorporating and economically validating drilling decisions. A computer system having a memory and central processing unit is provided and a knowledge store residing in the computer system is populated with data. The data may include surface drilling parameter data, bottomhole assembly data, bit records, measurement-while-chilling data, logging-while-drilling data, drilling event data, and lessons learned data. The data may be correlated data from one or more offset wells. One or more computerized static or dynamic contextual earth models are provided and used to dynamically incorporate and economically validate the drilling decisions. The one or more earth models can be updated in real-time.

A caliper tool used on a drilling tubular and having extensible members that remain decoupled with respect to the borehole wall during caliper measurements and while the extensible members are extended to allow movement in and through the borehole. A processor processes known and measured information to determine the size and shape of the borehole. Formation evaluation instruments may be included to allow formation evaluation substantially simultaneously with the caliper measurements.

A well fluid sampling tool is provided. The sampling tool includes at least one insulated sample chamber mounted in a tool collar. The tool collar may be coupled with a drill string such that, when the tool collar is deployed in a well bore, selected sample chambers may receive a fluid sample from outside the drill string without removing the drill string from the well bore (e.g., during measurement while drilling or logging while drilling operations). A heating module in thermal communication with at least one of the sample chambers is disposed to selectively heat the sample chambers in thermal communication therewith. The sampling tool may be particularly useful for acquiring and preserving substantially pristine formation fluid samples.

A logging while drilling tool includes a directional resistivity antenna and an antenna shield having. The shield has at least one slot having at least one electrically open end formed therein. The antenna shield may include a base portion and a plurality of spaced apart fingers extending away from the base portion such that the finger ends are electrically isolated from the tool body and from one another. The antenna shield may alternatively include a plurality of spaced apart plates that are electrically isolated from the tool body and from one another. These antenna shields have been found to provide suitable physical protection for sensitive antenna components while at the same time being substantially transparent to both z-mode and x-mode electromagnetic waves.

An earth model is formed in real time during drilling of a well by incorporating up-to-the-minute knowledge derived from geology, seismic, drilling, and engineering data. The process of forming the model utilizes Logging-While-Drilling (LWD) or Measuring-While-Drilling (MWD) data directly from the drilling rig as the well is drilled. The LWD or MWD data is sent to visualization centers and compared with other data such as existing geological models, the proposed well plan and present interpretation of the subsurface stratigraphy. The results of the comparison enable experts to analyze anomalous results and update the geological model within minutes of penetration of a formation during drilling. Well drilling efficiency is improved, and an “on-the-spot” road map is provided for maximal reservoir contact and pinpoint accuracy.

An assembly and methods for constructing a MONOWELL includes a monodiameter casing disposed in a monodiameter wellbore having diametric efficiency with a monobore production delivery system disposed within the monodiameter casing. An assembly for constructing a monodiameter wellbore includes a bottomhole assembly having a overgauge hole drilling member, a directional steering assembly, a measurement while drilling tool, and a logging while drilling tool; a work string attached to the bottomhole assembly and extending to the surface; drilling fluids flowing through the work string and bottomhole assembly; chemical casing casing the borehole; expandable casing disposed in the wellbore; and a sealing composition disposed between the expandable casing and the wellbore.

Integrated drilling and evaluation systems and methods for drilling, logging and testing wells are provided. The drilling and evaluation systems are basically comprised of a drill string, a drill bit carried on a lower end of the drill string for drilling a well bore, logging while drilling means included in the drill string for identifying subsurface zones or formations of interest, packer means carried on the drill string above the drill bit for sealing a zone or formation of interest below the packer means, and a fluid testing means included in the drill string for controlling the flow of well fluid from the zone or formation of interest into the drill string. The drilling and evaluation systems and methods for using the systems allow one or more subsurface zones or formations of interest in a well to be drilled, logged and tested without the necessity of removing the drill string from the well.

Acoustic telemetry devices and methods that provide directional detection. In one embodiment, a disclosed acoustic telemetry device comprises at least two acoustic sensors and an electronics module. A first of the acoustic sensors detects a communication signal that propagates along a tubing string in a first direction. A second of the acoustic sensors is configured to detect the communication signal before the first acoustic sensor. The electronics module combines the detection signals from the acoustic sensors to obtain a combined signal that substantially excludes signals propagating in a direction opposite to the communication signal. Such signal suppression may significantly enhance the communication signal's signal-to-noise ratio, thereby increasing channel capacity. The acoustic telemetry device may be configured to support logging while drilling and/or full-duplex communication.

A rotating, transversely magnetized, magnet on a drill collar induces magnetization in a casing of a preexisting well. A coil rotating synchronously with the magnet produces a current at twice the frequency of rotation and having an amplitude that depends upon the distance from the magnet to the preexisting well. Alternatively, a variable magnetic field is produced in the casing using a switchable magnet. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

Methods for three-dimensionally characterizing a reservoir while drilling a high angle or horizontal wellbore through the reservoir are disclosed. An initial reservoir model for the reservoir is selected and a section is extracted for a planned trajectory of the wellbore. A secondary model is generated by performing secondary modeling for at least part of the planned trajectory. An area of interest is identified within the secondary model where statistical uncertainty is high. Possible causes of the statistical uncertainty are identified for the area of interest within the secondary model that are not present or accounted for in the initial reservoir model. A set of parameters for the area of interest are defined at that are based on the possible causes of statistical uncertainty. The area of interest is logged with at least one logging while drilling LWD tool. Sensitivities of the LWD tool response to the subset of parameters are evaluated by performing at least one tertiary model for a range of the subset of parameters. The most sensitive parameters from the subset of parameters and corresponding measurements are identified. One or more real-time LWD measurements to be used for proactive well placement along the planned trajectory are identified and are based on the most sensitive parameters. The initial reservoir model is updated while drilling with information from the tertiary model. The model update is based on physics-based modeling or on inversion and on running multiple models and selection of a best candidate model based on correlations between the tool measurements and modeled results for each geologic model.

A resistivity tool for investigating a wall of a borehole drilled with a non-conductive mud includes a tool body adapted to be incorporated in a logging-while-drilling tool assembly; a resistivity sensor disposed on the tool body, wherein the resistivity sensor comprises a sensor pad supporting a current injector electrode, a current return electrode, and an array of measurement electrodes, and a circuitry for controlling current injection from the current injector electrode and for measuring voltage difference between electrodes in the array of measurement electrodes, wherein the current injector electrode and the current return electrode are disposed near opposite ends of the sensor pad and the array of measurement electrodes is disposed between the current injector electrode and the current return electrode, wherein the sensor pad is constructed of an insulating material and includes a conductive shielding member, or wherein the sensor pad is constructed of a conducting material and includes insulating sections around the electrodes.

A method for determining concentrations of naturally occurring radioactive elements in earth formation by analysis of gamma ray energy spectra measured by at least one gamma ray detector while the borehole is being drilled. Gain of the gamma ray detector is controlled automatically through analysis of the spectra. The one or more gamma ray detectors are disposed at the periphery of the downhole instrumentation to maximize sensitivity. Elemental concentrations of naturally occurring radioactive elements such as potassium, uranium and thorium are measured either as a function of depth in the borehole, or as a function of aximuthal sectors around the borehole wall, or as a function of both depth and azimuthal sectors.

A method of drilling a well. The method includes calculating an estimated formation dip angle, wherein said estimated formation dip angle being based on offset well data, seismic data, core data, pressure data. Next, the method includes drilling a well with a logging while drilling means so that real time logging data is generated along with drilling data and calculating an instantaneous formation dip angle. Next, real time logging data is obtained and a target formation window is projected ahead of the well path that includes a top of formation and a bottom formation. The method includes monitoring the real time logging and drilling data and drilling the well through the target formation window. The method further includes changing the estimated instantaneous formation dip based on the obtained data and adjusting the target formation top and bottom window.

Stoneley-wave data acquired in the LWD environment are used to characterize/estimate formation permeability. Real-time Stoneley-wave time-delay/slowness and center-frequency/attenuation data are used to indicate/characterize formation permeability even during drilling. The use of stabilizers mounted at the tool ends helps maintain the tool position from severe decentralization, reducing ambiguities in the permeability characterization/estimation. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

Apparatus and methods for measuring gamma ray energy spectra wherein the gain of the measurement system is continuously and automatically adjusted to a standard gain. Gain of the system is controlled automatically through analysis of the measured energy spectra. Alternately, the gain of the system is controlled by the use of a calibration source and the operation of the system at a standard and amplified gain. Gain control can be improved further by combining both the spectral analysis and calibration source methodology. The system can be embodied in a wireline or logging-while-drilling borehole logging systems that measure naturally occurring or induced gamma ray spectra. The system can also be used in non-borehole applications including non-borehole gamma ray spectral systems such as computer-aided-tomography scan systems, security scanning systems, radiation monitoring systems, process control systems, analytical measurement systems using activation analysis methodology, and the like.

A method for directing bore-hole drilling in a target earth formation includes the following steps: providing drilling equipment having a bottom hole assembly that includes a controllable directional drilling subsystem, and a logging-while-drilling directional measurement tool with a look-around and look-ahead capability; determining the presence of a predetermined type of formation characteristic in the target formation; and navigating a drill path in the target formation with the drilling equipment, including receiving measurement signals from the directional measurement tool, obtaining, from the received measurement signals, indications of formation parameters with respect to the formation characteristic in the target formation, and controlling the directional drilling subsystem to drill in a direction determined as a function of the obtained indication of formation parameters.

A method and apparatus for downhole coring while receiving logging-while-drilling tool data. The apparatus includes core collar and a retrievable core barrel. The retrievable core barrel receives core from a borehole which is sent to the surface for analysis via wireline and latching tool The core collar includes logging-while-drilling tools for the simultaneous measurement of formation properties during the core excavation process. Examples of logging-while-drilling tools include nuclear sensors, resistivity sensors, gamma ray sensors, and bit resistivity sensors. The disclosed method allows for precise core-log depth calibration and core orientation within a single borehole, and without at pipe trip, providing both time saving and unique scientific advantages.

An apparatus for obtaining tool face angles on a rotating drill collar in substantially real time is disclosed. In one exemplary embodiment the apparatus includes a magnetoresistive magnetic field sensor deployed in a tool body. The apparatus further includes a programmed processor configured to calculate tool face angles in substantially real time from the magnetic field measurements. The programmed processor may optionally further be configured to correlate the calculated tool face angles with logging while drilling measurements for use in borehole imaging applications.

Methods and apparatus facilitating logging-while-drilling (LWD) using a multi-pole acoustic transmitter source. The multi-pole transmitter source enables measurement of formation velocities, including shear wave velocities through formations that are slower than velocities through local fluids. The methods and apparatus are particularly well suited for LWD and wireline seismic surveys in which both the seismic or acoustic source and receivers are both deployed in a borehole, but may also be used for VSPs (vertical seismic profiling).

A borehole logging system for determining bulk density, porosity and formation gas/liquid fluid saturation of formation penetrated by a borehole. Measures of fast neutron radiation and inelastic scatter gamma radiation, induced by a pulsed neutron source, are combined with an iterative numerical solution of a two-group diffusion model to obtain the formation parameters of interest. Double-valued ambiguities in prior art measurements are removed by using the iterative solution of the inverted two-group diffusion model. The system requires two gamma ray detectors at different axial spacings from the source, and a single neutron detector axially spaced between the two gamma ray detectors. The system can be embodied as a wireline system or as a logging-while-drilling system.

A system for measuring the size of a borehole penetrating an earth formation is disclosed. The system uses a neutron source and a least one neutron detector. The neutron detector responds primarily to the composite hydrogen content of material within the borehole and formation upon irradiation by the neutron source. A partition response function is used to delineate the portion of the detector response resulting from borehole and from the formation. Since the detector response from the borehole can be isolated using the partition function and the hydrogen content of the borehole fluid is generally known, the size of the borehole can be determined from borehole response portion of the composite detector response if combined with a neutron porosity measurement of the formation. The neutron porosity measurement can be obtained independently, or by combining the neutron detector response with the response of a second neutron detector at a different axial spacing from the neutron source. The system is applicable in both logging-while-drilling and wireline logging operations.