Response of a triaxial induction logging tool in a homogeneous biaxial anisotropic formation

2009 ◽  
Author(s):  
Ning Yuan ◽  
Xiao Chun Nie ◽  
Richard Liu
Keyword(s):  
Induction Logging ◽  
Anisotropic Formation ◽  
Logging Tool

scholarly journals Application of OpenMP to Wireline Triaxial Induction Logging in 1D Layered Anisotropic Medium

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Zhijuan Zhang ◽  
Ning Yuan ◽  
Richard Liu
Keyword(s):  
Real Time ◽  
High Performance ◽  
Data Interpretation ◽  
Forward Modeling ◽  
Computer Hardware ◽  
Time Inversion ◽  
Data Inversion ◽  
Induction Logging ◽  
Anisotropic Formation ◽  
Logging Tool

Efficient and accurate forward modeling of logging tool responses is essential for data inversion in the log data interpretation in both real time and postprocessing. With the aggressive advancement of various high-performance computing techniques and computer hardware technology, it is possible to significantly improve the efficiency of the forward modeling. In this paper, we apply OpenMP to parallelize the simulation of triaxial induction logging tools in 1D multilayered anisotropic formation. The parallel process is explained in detail and numerical examples are presented to demonstrate the effect of the parallel programming. Comparison of the original code and the parallel code shows that the latter is much faster without loss of accuracy, which is very promising for future real-time inversion.

A semianalytic solution to the response of a triaxial induction logging tool in a layered biaxial anisotropic formation

Geophysics ◽  
2016 ◽  
Vol 81 (1) ◽  
pp. D71-D82 ◽  
Author(s):  
Zhili He ◽  
Kai Huang ◽  
Richard C. Liu ◽  
Chen Guo ◽  
Zhao Jin ◽  
...  
Keyword(s):  
Layered Media ◽  
Published Data ◽  
Field Equations ◽  
Data Inversion ◽  
Tool Axis ◽  
Induction Logging ◽  
Anisotropic Formation ◽  
Transverse Isotropic ◽  
Transverse Electromagnetic ◽  
Logging Tool

We have developed a forward-modeling method to compute the response of a triaxial induction logging tool in a layered biaxial anisotropic dipping formation without borehole and invasion zones. The purpose of this development is to provide a fast-forward computation algorithm to handle cracks in transverse isotropic (TI) formations in oil exploration, which is a mathematically challenging problem for log data inversion. We solve for the spectral-domain transverse electromagnetic (EM) field equations, propagation matrix, and reflection matrix in a biaxial anisotropic planarly layered media. The EM fields in the space domain are obtained by a 2D inverse Fourier transform. We derive formulations of the EM fields generated by three orthogonal transmitting coils in a fully anisotropic layered media. The proposed formulations are based on arbitrary relative dipping and azimuthal and tool angles; thus, we obtain the full coupling matrix connecting source excitations and magnetic fields anywhere along the tool axis. Computation results using this method in the response of triaxial induction tools in several cases were compared with published data in TI formations and biaxial layered formations. Our results agreed very well with the published data.

Enhancing the operating range of the multicomponent induction logging tool

2003 ◽  
Author(s):  
Berthold F. Kriegshäuser ◽  
André Santos ◽  
Liming Yu
Keyword(s):  
Operating Range ◽  
Induction Logging ◽  
Logging Tool

Transient response of an induction logging tool in a borehole

Geophysics ◽  
1981 ◽  
Vol 46 (9) ◽  
pp. 1291-1300 ◽  
Author(s):  
W. C. Chew ◽  
S. Gianzero ◽  
K. J. Kaplin
Keyword(s):  
Transient Response ◽  
Simple Algorithm ◽  
Induction Logging ◽  
Vertical Magnetic Dipole ◽  
Long Time ◽  
Double Fourier Transform ◽  
The Difference ◽  
Direct Numerical Integration ◽  
Homogeneous Formation ◽  
Logging Tool

The long time transient response is developed for a point coil transmitter (vertical magnetic dipole) located in a wellbore surrounded by a homogeneous formation. A simple algorithm is derived for the apparent conductivity signal based on the difference between the voltage nulls in a pair of receiver coils which are displaced vertically from the transmitter along the axis of the wellbore. A justification of these results is provided by means of a direct numerical integration (double Fourier transform) and also two separate approximate approaches.

A weak-anisotropy approximation to multicomponent induction responses in cross-bedded formations

Geophysics ◽  
2006 ◽  
Vol 71 (4) ◽  
pp. F61-F66 ◽  
Author(s):  
Tsili Wang
Keyword(s):  
Apparent Resistivity ◽  
Transversely Isotropic ◽  
Anisotropy Ratio ◽  
Weak Anisotropy ◽  
Bedding Planes ◽  
Geometric Average ◽  
Induction Logging ◽  
Anisotropic Formation ◽  
The Cross

The multicomponent induction logging response to a cross-bedded formation has been modeled under a weak-anisotropy approximation. With the approximation, a cross-bedded formation can be modeled as a transversely isotropic (TI) medium. The validity of the approximation has been tested for the main (coplanar and coaxial) components of the induction response. The conditions for the weak-anisotropy approximation to be valid depend on the component of the response. For the coplanar components, the approximation is valid for an anisotropy ratio up to 2 if the relative dipping angle between the cross-bedded formation and the borehole axis is below [Formula: see text]. For the coaxial component, the approximation reduces to a previously established result that the apparent resistivity for such a component is the geometric average of the resistivities, parallel and perpendicular to the bedding planes of an anisotropic formation, respectively, if the borehole is ignored. Hence, the approximation holds for the coaxial component regardless of the anisotropy ratio.

An approximate 3D computational method for real-time computation of induction logging responses

Geophysics ◽  
2014 ◽  
Vol 79 (3) ◽  
pp. E137-E148 ◽  
Author(s):  
Silvian Bensdorp ◽  
Steen A. Petersen ◽  
Peter M. van den Berg ◽  
Jacob T. Fokkema
Keyword(s):  
Integral Equation ◽  
Computational Method ◽  
Small Scale ◽  
Major Drawback ◽  
Heterogeneous Structures ◽  
Integral Equation Formulation ◽  
Induction Logging ◽  
Homogeneous Background ◽  
Logging Tool ◽  
Dominant Part

Over many years, induction logging systems have been used to create well formation logs. The major drawback for the utilization of these tools is the long simulation time for a single forward computation. We proposed an efficient computational method based on a contrast-type of integral-equation formulation, in which we applied an approximation for the 3D electromagnetic field. We assumed that the dominant contribution in the integral equation is obtained by the contribution around the singularity of Green’s kernel. It is expected that the approximation yields reliable results when the (homogeneous) background conductivity around the logging tool is close to the actual conductivity at the location of the tool. We have developed a data-driven method to determine this background conductivity from the dominant part of the measured coaxial magnetic fields, which are mainly influenced by the conductivity at the tool sensors. For a synthetic model, the results were compared to the ones of a rigorous solution of the integral equation and show a good simulation response to small-scale variations in the medium. Further, the method was used to simulate the response of a realistic reservoir model. Such a model is created by a geological modeling program. We concluded that our approximate method was able to improve the approximation results in highly heterogeneous structures compared to the Born approximation and provide an effective medium-gradient around the tool. Our method, based on the wavefield approximation, also estimates the error, and hence yields a warning when the method becomes unreliable.

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