Serving the petroleum industry worldwide ... a leader in formation testing, rheology, MWD telemetry and electromagnetics.
Computational electromagnetics for log analysis and MWD tool design ...
Real world logging problems are beset with difficulties. Formations are multilayered, anisotropic, containing boreholes with conductive mud. To make matters worse, electromagnetic logging tools, oriented at dip, induce charges at interfaces; coil diameters may be comparable to layer thicknesses, rendering dipole assumptions questionable; oblique transmitters and receivers, which may wrap around metal mandrels, are typically eccentric in the hole; and finally, frequencies may range from induction to dielectric.
What do your attenuation and phase delay measurements really mean?
If you're familiar with service company models, you'll realize that few of the above effects are accurately modeled in industry simulators. And if you're running the latest triaxial induction tools, you need the best models available to assess the economic potential of your reservoir.
What you don't want are different models developed by different researchers, coded by different programmers, working at different companies ... and all claiming PROPRIETARY when you raise legitimate questions.
StrataMagnetic Software, LLC has developed just the simulator you need, to handle all of the effects noted above. And we're not talking about supercomputing ... our state-of-the-art e/m approach runs in seconds on personal computers, solving Maxwell's equations in their most general form. This capability is augmented by integrated three-dimensonal color graphics, which automatically display everything you've always wanted to know about E and B, or equivalently, A and V.
And importantly, we're completely open about our technology. Our simulator, validated with numerous test calculations, has been licensed to international companies for tool design and well log interpretation.
What did we do? And how?
At StrataMagnetic Software, LLC, we're open about the methods we use and why, so we'll start by telling you the complete story right now ...
We assume exact coil diameters, ranging from inches to dozens of feet, making the model useful in environmental surface logging as well. An oblique transmitter is represented by eight equidistant current source points on a variable finite difference mesh. Non-zero coil diameters, as indicated below, also allow numerous modeling options.
The computing domain for the general complex Helmholtz equation system may contain a drill collar; the transmitter and receiver coils may traverse distinct layers, and the tool itself may be eccentered with invasion.
If you're wondering which Maxwell formulation we've solved, here it is ... no approximations, no unrealistic assumptions, the real thing. And if you're modeling nonlinear constitutive equations, the approach lends itself naturally to their solution - an interative relaxation method is used and nonlinearity is not a concern.
Here's an example of interfacial charge induced by a tool at dip.
And an example of the electric field (above) obtained for different combinations of real world complexities.
Here's a really difficult one ... layered media with high contrast resistivity.
We've effortlessly computed the axial magnetic field for a range of interesting problems, a capability useful in NMR design. Electric and magnetic field post-processing are standard in our approach and three-dimensional color plots are created automatically.
New computational technology, addressing an old problem ...
We're fast because our "intelligent" point relaxation solvers take advantage of inherent physical dissipation, high in a dimensionless sense for most petroleum reservoirs, to accelerate numerical convergence.
Our numerical model, first published a decade ago in China's Well Logging Technology journal, and subsequently licensed to several international companies, has gotten better ... much better.
We'll share our findings with you right now ...
You can read the Abstract and paper above, but if you can't ... we have a more complete report, illustrated with three-dimensional color graphics, containing the full boundary value problem formulation, detailed solution strategies, finite difference operators for properties (and derivatives) with discontinuities, numerous case studies, and so on, written entirely in English.
This definitive study on electromagnetic modeling in modern logging applications is yours for $99 USD, plus $16 USD shipping and handling (total of $115 USD). Order directly from E&P Press at epPublishers@aol.com.
Can't wait to simulate? Why not incorporate our source code in your company system? Purchase our complete modeling system right now ... call or write the developer for details today.
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