3812 results about "Well logging" patented technology

A method is disclosed for determining a position of a wellbore with respect to layer boundaries in earth formations. The method includes projecting a trajectory of the wellbore onto an initial model of the earth formations, selecting a segment of the trajectory and calculating along the segment expected responses of a well logging instrument. Differences between the expected responses and responses measured by the instrument along the segment are determined. The model is adjusted, the expected responses are recalculated and the differences are again determined. These are repeated until the differences fall below a selected threshold. In one embodiment, the trajectory of the wellbore can be adjusted to remain within a selected distance of a selected one of the layer boundaries.

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.

Method and apparatus for deriving information regarding a subsurface geophysical formation. Well logging data is acquired for the subsurface geophysical formation. Geometrical parameters for the subsurface geophysical formation are determined by inversion processing of the acquired well logging data in a pattern space while formation conductivities for the subsurface geophysical formation are determined by inversion processing of the acquired well logging data in a measurement space. The processing may be iteratively applied until satisfied formation parameters are achieved.

A model for predicting fracturing in shale can minimize surface disruption, protect groundwater, maximize efficiency of hydraulic fracturing, and manage fluids used in unconventional gas development. The model provides a more comprehensive understanding of the geological, geophysical, and geomechanical properties of shales and imbeds these properties in geomechanical computer simulations to predict both the reservoir performance from the fracturing, and the associated microseismic events generated by fracturing. Since the geological and geophysical properties can be estimated from surface seismic, well logs, and geologic concepts with regional context; the performance of the fracturing can be predicted and optimized. Since the microseismic events can be predicted with the model, the simulations can be verified and the model can be updated to be consistent with the observed microseismic.

The invention relates to a method for continuously quantitative evaluation of pore structures of reservoir strata by utilizing nuclear magnetic resonance well logging data, so as to divide types of the reservoir strata. The method comprises the following steps of: classifying T2 spectrums according to parameters reflecting differences of reservoir strata, and carrying out a nonlinear calibration method on different T2 spectrums to obtain a continuously distributed capillary pressure curve of the reservoir strata; obtaining continuous reservoir stratum pore throat radius distribution and pore structure parameters by utilizing the nuclear magnetic capillary pressure curve; and evaluating the pore structure of each reservoir stratum on the basis of the nuclear magnetic capillary pressure curve, the features of the reservoir stratum pore throat radius distribution and the pore structure parameters, and dividing types of the reservoir strata. Through the adoption of the method, the nuclear magnetic capillary pressure curve on each depth point can be continuously obtained by utilizing the nuclear magnetic resonance well logging data, the pore structure of each reservoir stratum can be quantitatively evaluated according to the reservoir stratum pore throat radius distribution and the pore structure parameters of the reservoir stratum, and the types of the reservoir strata are classified, therefore, the exploitation and development efficiency of complicated oil-gas reservoir is improved.

Method for prediction of mechanical properties used in the description of large-strain plastic deformation for any subsurface rock strata of interest. The method is not specific to any geographic region, geological environment or subsurface depth interval, nor is it constrained to a specific lithology or plastic mechanical property. Predictive algorithms for triaxial compressive strength and rock compressibility are derived (23) from a mechanical properties database (21), and used to predict subsurface variation in mechanical properties such as rock strength or rock compressibility, with petrophysical properties generated from, for example, geophysical wireline logs as input to the algorithms (26).

Techniques and a system for performing geological interpretation operations in support of energy resources exploration and production perform well log correlation operations for generating a set of graphical data describing the predetermined geological region. The process and system interpret the geological environment of the predetermined geological region from measured surface and fault data associated with the predetermined geological region. Allowing the user to query and filter graphical data representing the predetermined geological region, the method and system present manipulable three-dimensional geological interpretations of two-dimensional geological data relating to the predetermined geological region and provide displays of base map features associated with the predetermined geological region. The method and system automatically update the manipulable three-dimensional geological interpretations of two-dimensional data relating to the predetermined geological region, as well as calculate three-dimensional well log and seismic interpretations of geological data relating to the predetermined geological region.

Array quadrupole data obtained in a LWD environment are processed to determine the shear velocity of an earth formation taking into account dispersion effects caused by the logging tool. When this processing is done in an azimuthally anisotropic formation, the shear velocity that is obtained is the slow shear velocity. When 4C (cross-dipole) data are also obtained, then both the fast and slow shear velocities of an azimuthally anisotropic formation can be obtained.

A well logging instrument housing includes an electrically non-conductive tube and at least one layer of fiber embedded in a matrix surrounding an exterior of the tube. The at least one fiber layer includes at least one carbon fiber. The at least one or carbon fiber is arranged to have substantially no closed loops.

A method for determining a formation fluid property includes acquiring a suite of nuclear magnetic resonance (NMR) measurements of a fluid sample using a pulse sequence that includes pulsed field gradient pulses for encoding diffusion information, wherein each NMR measurement in the suite is acquired with a different value in a parameter in the pulsed field gradient pulses for producing a different diffusion effect, wherein the acquiring is performed in a formation fluid sampling tool in a borehole; inverting the suite of NMR measurements to produce a distribution function that relates diffusion properties of the fluid sample with an NMR property of the fluid sample; and determining the formation fluid property from the distribution function.