187 results about "Geosteering" patented technology

This invention is directed to a downhole method and apparatus for simultaneously determining the horizontal resistivity, vertical resistivity, and relative dip angle for anisotropic earth formations. The present invention accomplishes this objective by using an antenna configuration in which a transmitter antenna and a receiver antenna are oriented in non-parallel planes such that the vertical resistivity and the relative dip angle are decoupled. Preferably, either the transmitter or the receiver is mounted in a conventional orientation in a first plane that is normal to the tool axis, and the other antenna is mounted in a second plane that is not parallel to the first plane. This invention also relates to a method and apparatus for steering a downhole tool during a drilling operation in order to maintain the borehole within a desired earth formation. The steering capability is enabled by computing the difference or the ratio of the phase-based or amplitude-based responses of the receiver antennas which are mounted in planes that are not parallel to the planes of the transmitter antennas. Although this invention is primarily intended for MWD or LWD applications, this invention is also applicable to wireline and possibly other applications.

A novel on-the-fly data processing technique is useful for extracting signals from the azimuthal variation of the directional measurements acquired by a logging tool within a borehole. The relevant boundary, anisotropy and fracture signals are extracted from the formation response through fitting of the azimuthal variation of the measured voltages to some sinusoidal functions. The orientation of the bedding is also obtained as a result. The extracted directional signals are useful for obtaining boundary distances and making geosteering decisions. Two techniques involving inversion and cross-plotting may be employed, depending on the nature of the boundary. A Graphical User Interface (GUI) is part of a system to facilitate flexible definition of inversion objectives, for improving the inversion results, and for visualization of the formation model as well as inversion measurements.

An improved induction tool for formation resistivity evaluations. The tool provides electromagnetic transmitters and sensors suitable for transmitting and receiving magnetic fields in radial directions that are orthogonal to the tool's longitudinal axis with minimal susceptibility to errors associated with parasitic eddy currents induced in the metal components surrounding the transmitter and receiver coils. Various transmitter receiver combinations are provided to select sensitivity to a desired reservoir formation properties, for example, different orientations xy, xz, yz, 20-40, 20-90, and combinations, such as, Symmetric-symmetric; Asymmetric-symmetric; and Asymmetric-asymmetric. Measurements made with a multi-component logging instrument when used in a substantially horizontal, vertical or deviated borehole in earth formations are diagnostic of the direction of resistive beds relative to the position of the borehole.

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.

A method for geosteering while drilling a formation includes generating a plurality of formation models for the formation, where each of the plurality of the formation models includes a set of parameters and a resistivity tool therein and locations of the resistivity tool differ in the plurality of the formation models. The method may also include computing predicted tool responses for the resistivity tool in the plurality of formation models, acquiring resistivity measurements using the resistivity tool in the formation, and determining an optimum formation model based on a comparison between the actual tool response and the predicted tool responses. The method may also include steering a bottom home assembly based on the optimum formation model.

Method of analyzing a subterranean formation traversed by a wellbore. The method uses a tool comprising a transmitter antenna and a receiver antenna, the subterranean formation comprising one or more formation layers. The tool is suspended inside the wellbore, and one or more electromagnetic fields are induced in the formation. One or more time-dependent transient response signals are detected and analyzed. Electromagnetic anisotropy of at least one of the formation layers is detectable. Geosteering cues may be derived from the time-dependent transient response signals, for continued drilling of the well bore until a hydrocarbon reservoir is reached. The hydrocarbon may then be produced.

Measurements made with a multicomponent logging instrument when used in a substantially horizontal borehole in earth formations are diagnostic of the direction of beds relative to the position of the borehole. When the logging instrument is conveyed on a drilling assembly, the drilling trajectory may be maintained to follow a predetermined trajectory or to maintain a desired distance from a boundary such as an oil-water contact.

A closed-loop method for geosteering includes acquiring logging while drilling data and processing the logging while drilling data downhole while drilling to obtain a geosteering correction (a correction to the drilling direction based upon the LWD measurements). The geosteering correction is further processed downhole to obtain new steering tool settings which are then applied to the steering tool to change the direction of drilling. These steps are typically repeated numerous times without the need for uphole processing or surface intervention.

A three-coil bucking system is used for determination of a formation resistivity property ahead of the drill bit. The conductive drill pipe is provided with non-conductive inserts in the proximity of at least one transmitter and at least two receivers. Transient electromagnetic signals are processed to give the estimate of the resistivity property and for geosteering.

A transverse induction transmitter on an instrument induces currents in an earth formation when it is pulsed. Transient measurements made at transverse and axial receivers are used for determination of a distance to a bed boundary. This may be used to control the drilling direction. Alternatively, a transmitter on an instrument having a conductive body induces currents in the earth formation. Transient signals are measured and the effect of the conductive body is removed by using a reference signal measured in a homogenous space.

In some embodiments, an apparatus and a system, as well as a method and an article, may operate to acquire input data to determine properties of a formation, using a combination of down hole transmitters and receivers, to select a portion of the input data using a formation model chosen from a plurality of down hole tool response models in a formation model database, based on a valid sensitive range for the bed boundary distance and a greatest signal-to-noise ratio (SNR), and to solve for at least resistivity formation parameters in the properties using the chosen formation model and the selected portion of the input data. The database may be updated with boundary distance and the resistivity formation parameters. Additional apparatus, systems, and methods are disclosed.

A steering tool configured for making azimuthal and non-azimuthal formation evaluation measurements is disclosed. In one embodiment a rotary steerable tool includes at least one formation evaluation sensor deployed in the steering tool housing. The steering tool may include, for example, first and second circumferentially opposed formation evaluation sensors or first, second, and third formation evaluation sensors, each of which is radially offset and circumferentially aligned with a corresponding one of the steering tool blades. The invention further includes methods for geosteering in which a rotation rate of the steering tool housing in the borehole (and therefore the rotation rate of the formation evaluation sensors) is controlled. Steering decisions may be made utilizing the formation evaluation measurements and / or derived borehole images.

The invention relates to an array coil system of an azimuthal electromagnetic wave resistivity logging instrument while drilling, wherein the array coil system (2) is wound in a corresponding hole or groove in a coil carrier (1) and comprises a plurality of groups of transmitting coils and a plurality of groups of receiving coils; the transmitting coils are symmetrically distributed longitudinal coils of different spacing; and the receiving coils are symmetrically distributed on the two sides of the center of the array coil system (2) and comprise longitudinal coils with coil system magnetic dipole direction coaxial with the instrument and transverse coils with coil system magnetic dipole direction vertical with the instrument. According to the array coil system, the characteristics of stratum azimuth, dip, resistivity and anisotropy can be achieved, and information such as stratum structure change and distance from a wellbore to the boundary of a reservoir stratum can also be achieved; and the array coil system has an important effect on accurate geological guidance and reservoir stratum evaluation in a well drilling process. The array coil system is suitable for the technical field of logging in oil and gas exploration.

The invention relates to a double induction unit resistance meter that includes drill collar, V shaped groove, emitting unit, coupling unit, receiving unit, emitting circuit module, receive controlling circuit module, high pressure sealing cover board, upper sliding circle connector, down sliding circle connector, and wire hole. It could test two ground unit resistance and the emitting coil and the receiving coil are independent. It could test the ground unit resistance real time in drilling process, and could explain the ground invade situation and calculate ground water saturation, distinguish the lithology of the layer location and the hydro-alteration feature. It is suitable to take ground guides in well drilling projects.

The invention discloses a geosteering method for landing a horizontal well and relates to the technical field of well-drilling exploration and development of petroleum and natural gas, in particular relates to a geosteering method for landing a horizontal well after the sloping section is completed in the horizontal well drilling process. The geosteering method is characterized in that the target formation is exploited at a stable angle of inclination along the well trajectory with a certain deviation angle after the sloping section is completed before landing; when the on-site real-time data indicate that the target formation is reached, the target formation is drilled with an increasing angle of inclination until the well trajectory is parallel to the formation dip; and when the sand rock of the target formation is in the optimum display position, the target formation is drilled with a stable angle of inclination. Based on the on-site actual drilling data of the target well and the comprehensive consideration of two possibilities of vertical depth in advance and vertical depth delay of the target formation, the waste of horizontal sections is effectively reduced and the well trajectory is effectively protected from drilling through the target formation.

This invention is directed to a downhole method and apparatus for simultaneously determining the horizontal resistivity, vertical resistivity, and relative dip angle for anisotropic earth formations. The present invention accomplishes this objective by using an antenna configuration in which a transmitter antenna and a receiver antenna are oriented in non-parallel planes such that the vertical resistivity and the relative dip angle are decoupled. Preferably, either the transmitter or the receiver is mounted in a conventional orientation in a first plane that is normal to the tool axis, and the other antenna is mounted in a second plane that is not parallel to the first plane. This invention also relates to a method and apparatus for steering a downhole tool during a drilling operation in order to maintain the borehole within a desired earth formation. The steering capability is enabled by computing the difference or the ratio of the phase-based or amplitude-based responses of the receiver antennas which are mounted in planes that are not parallel to the planes of the transmitter antennas. Although this invention is primarily intended for MWD or LWD applications, this invention is also applicable to wireline and possibly other applications.

The invention discloses a rotary steering tool controlling method which can be used for determining the control mode and steering parameters of a steering tool, achieving automatic control over a hole trajectory, improving the working efficiency of the steering tool, and meeting the requirement of directional drilling for steering control. The method comprises the steps of acquiring surveying data and monitoring the trajectory. By the adoption of the method, steerable drilling efficiency is improved, hole trajectory control precision is improved, and the requirement of extended-reach well drilling, complicated geology structure horizontal well drilling and geosteering drilling for trajectory control can be met.

The invention relates to a fast and fine geological orientation method for a shale gas horizontal well. Materials are collected, an orientation comparing standard well and a reference well are determined, and an orientation sign layer and a target spot predicting scheme are determined; a well zone two-dimensional geological orientation model and a well zone three-dimensional geological orientation model are built and regulated, and a two-dimensional vertical section and the three-dimensional geological orientation model of a well to be oriented are amended in time; by means of the characteristics of lithological characters, well deflection, while-drilling gamma and the like of the well to be oriented, the standard well and the reference well, stratum comparing is conducted; the position where a drill is located is judged through three figures, one table and the like; whether the position where the drill is located is in a high-quality shale gas layer section or not is evaluated while drilling; whether an initial geological model is applicable or not is judged; through an equal-thickness comparing method a target spot A is determined and regulated, a target spot B is predicted, and a track of a borehole in a horizontal section is controlled; and the pass-through rate of a high-quality shale gas layer is calculated according to the statistic drilling-meeting thicknesses of a shale reservoir and a high-quality shale reservoir, whether the track is controlled to reach the target spot B or not is judged, and the fast geological orientation effect is evaluated. Fast orientation is achieved, the application range is wide, and application and popularization are easy.