Schlumberger Technology Corporation

Services Petroliers Schlumberger

Schlumberger Holdings Limited

Prad Research and Development Limited

Prad Research Development Limited

Keli Sun

Dzevat Omeragic

Aria Abubakar

Koji Ito

Steve F Crary

Tarek M Habashy

Qiming Li

Roger Griffiths

Gong Li Wang

Christopher Edward Morriss

Thomas D Barber

Gerald N Minerbo

Andrei Davydychev

Shahzad Asif

Tianxia Zhao

Xiao Bo Hong

A method includes receiving information for a subsurface region; based at least in part on the information, identifying sub-regions within the subsurface region; assigning individual identified sub-regions a dimensionality of a plurality of different dimensionalities that correspond to a plurality of different models; via a model-based computational framework, generating at least one result for at least one of the individual identified sub-regions based at least in part on at least one assigned dimensionality; and consolidating the at least one result for multiple sub-regions.

Earth model generation via measurements

Identifying the dielectric constant and/or the electrical resistivity of part of a geological formation may reveal useful characteristics of the geological formation. This disclosure provides methods, systems, and machine-readable media to determine dielectric constant or electrical resistivity, or both, using contraction mapping. Specifically, contraction mapping may be used with a function of wavenumber k to iteratively solve for values of dielectric constant and electrical resistivity until convergence is achieved. This may allow for convergence to a solution without computing partial derivatives and/or with fewer iterations than previous techniques.

Systems and methods for determining dielectric constant or resistivity from electromagnetic propagation measurement using contraction mapping

Techniques for log squaring using both directional and non-directional electromagnetic measurements are disclosed. The techniques described herein can be used for determining bed boundary locations and assigning resistivity values to each layer in a layered earth model, regardless of well deviation. Potential bed boundary locations can be derived from both directional and non-directional electromagnetic measurement data. The bed boundary locations from the directional and non-directional measurements can then be consolidated using a weighted averaging scheme, where weight can be dependent based on apparent formation dip. By combining the results from both directional and non-directional measurements, the log squaring techniques described herein can be used in most wells regardless of the well angle (the angle can be arbitrary). Once bed boundaries are selected, formation properties, such as horizontal resistivity (Rh) and vertical resistivity (Rv) can be assigned to the model layers.

Method for selecting bed boundaries and log squaring using electromagnetic measurements

Methods, computer-readable media, and systems are disclosed for applying 1D processing in a non-1D formation. In some embodiments, a 3D model or curtain section of a subsurface earth formation may be obtained. A processing window within the 3D model or curtain that is suitable for 1D inversion processing is determined, and a local 1D model for the processing window is built. A 1D inversion is performed on the local 1D model, and inverted formation parameters are used to update the 3D model or curtain section.

Methods, computer-readable media, and systems for applying 1-dimensional (1D) processing in a non-1D formation

A system and method discloses performing a fracture operation at a wellsite about a subterranean formation. The method involves, obtaining wellsite measurements by placing a downhole tool in a wellbore and using the downhole tool to acquire measurements of the subterranean formation, simulating the obtained wellsite measurements to determine formation parameters comprising conductivity tensors based on a formation model of the measured subterranean formation, validating the formation model by comparing the obtained wellsite measurements with the simulated wellsite measurements, generating fracture parameters and triaxiality indicators based on the validated formation model, and fracturing the subterranean formation based on the generated fracture parameters and triaxiality indicators.

Method for determining triaxial conductivity with arbitrary orientation using multiaxial electromagnetic measurements

Embodiments set forth in this disclosure providing techniques for determining formation parameters, such as horizontal resistivity (Rh), vertical resistivity (Rv), and dip, in high angle and horizontal wells using non-directional resistivity measurements. For example, a method is provided that may include using an electromagnetic logging tool to acquire non-directional resistivity measurements in a wellbore of a high angle or horizontal well. The method may also include defining a processing window that corresponds to a measurement point of the electromagnetic logging tool along a well trajectory that intersects a at least one bed boundary between two layers of a subsurface formation. The method may also include defining a formation structure and defining an initial set of formation parameters for each layer in the formation structure. Furthermore, the method may include inverting the formation parameters for each layer.

Method and apparatus for determining formation properties using non-directional electromagnetic measurements in high angle or horizontal wells

A multi-step electromagnetic inversion method is provided for determining formation resistivity, anisotropy and dip. An electromagnetic logging tool is used to obtain non-directional, anisotropy, and directional (including symmetrized and anti-symmetrized resistivity measurements) in a formation using an electromagnetic logging tool. Bed boundaries of the formation are first identified. A horizontal resistivity profile is obtained using the non-directional resistivity measurements, and a vertical resistivity profile is obtained using the anisotropy resistivity measurements. The vertical resistivity profile is improved using the directional resistivity measurements, while dip values are also obtained via an inversion using the directional resistivity measurements. Then, an inversion for each of vertical resistivity, horizontal resistivity, dip values, and bed boundaries is performed using all of the non-directional, anisotropy, and directional resistivity measurements to obtain a formation model.

Multilevel workflow method to extract resistivity anisotropy data from three-dimensional induction measurements

The present disclosure relates to a method to determine the vertical resistivity of a subsurface formation. A downhole logging tool having a plurality of spaced antennas, at least one of which is a transverse antenna, at least two of which are tilted antennas, and at least two of which are axial antennas is provided. Measurements involving the transverse and/or the tilted antennas of the downhole logging tool are obtained. Voltage ratios are formed using the measurements, and conditioning factors are formed by raising the determined voltage ratios not involving the transverse antenna to some arbitrary power. The sum of the exponents of the conditioning factors preferably equals one. A voltage ratio involving the transverse antenna is multiplied by the conditioning factors, and the vertical resistivity of the subsurface formation is determined using the resulting ratio.

Determining anisotropic resistivity

A method is provided for determining formation resistivity, anisotropy and dip from wellbore measurements includes moving a well logging instrument through subsurface formations. The instrument includes longitudinal magnetic dipoles and at least one of tilted and transverse magnetic dipoles. Formation layer boundaries and horizontal resistivities of the formation layers are determined from longitudinal magnetic dipole measurements. Vertical resistivities of the formation layers are determined by inversion of anisotropy sensitive measurements. Improved vertical resistivities of the formation layers and dips are determined by inverting symmetrized and anti-symmetrized measurements. Improved vertical resistivities, improved boundaries and improved dips are determined by inversion of the all dipole measurements. Improved horizontal resistivities, further improved layer boundaries and further improved dips are determined by inversion of all dipole measurements.

Growing community of inventors

Sugar Land, TX, United States of America

Keli Sun