Several established non-commercial inversion codes exist, but they typically require advanced knowledge to use effectively. Although field surveys using these methods are relatively straightforward, ERT and IP data require the application of inverse methods prior to any interpretation. This newly developed software is currently in use for real-time reservoir navigation and post-well analysis.Electrical resistivity tomography (ERT) and induced polarization (IP) methods are now widely used in many interdisciplinary projects. Applications of the developed software will be shown on a series of synthetic examples and field data from the North Sea and Gulf of Mexico (GOM). This capability enables interpretation of real-time resistivity data, including azimuthal and extra-deep measurements.Ī graphical user interface (GUI) was developed to provide an interactive environment for each stage of the resistivity data interpretation process: preview of input resistivity logs, initial preprocessing and filtering of raw data, creation of initial guess, running inversion and viewing inversion results, and quality-control indicators. The algorithm has good performance and excellent convergence because of its enhanced capability of avoiding local minima. The inversion algorithm is based on the method of the most-probable parameter combination. The following model parameters are determined in real time: horizontal and vertical resistivities and thickness of each layer, formation dip, and azimuth. The core of the newly developed software is an inversion algorithm based on transversely isotropic layered Earth with an arbitrary number of layers. However, real-time interpretation software is very often based on simplified resistivity models that can be inadequate and lead to incorrect geosteering decisions.

These tools are generally used for reservoir navigation and real-time formation evaluation. Modern logging-while-drilling (LWD) extra-deep and azimuthal resistivity tools acquire multicomponent, multispacing, and multifrequency data that provide sufficient information for resolving the surrounding formation parameters. On the basis of these results, a decision to change the direction of drilling could be made. For proper well placement, it is necessary to calculate in real-time the parameters of the formation we are drilling in and the parameters of formations we are approaching. In petroleum exploration, reservoir navigation is used for reaching a productive reservoir and placing the borehole optimally inside the reservoir to maximize production.

Resistivity interpretation software