Cyrille Levesque

Practical Implications of Nonlinear Inversion For Cross-well Electromagnetic Data Collected In Cased-wells

This paper first summarizes the theory of providing resistivity images from cross-well electromagnetic (EM) measurements in metal cased holes. Metallic casing significantly attenuates EM signals. As a result, low frequencies are required to acquire useful EM signals in cased holes, which reduces the resolution within the inversion images. Comparison of casing materials shows that chromium steel casing attenuates the EM signals much less than carbon steel casing. Although cross-well EM technology can be successfully applied in open/fiberglassto-open/fiberglass and open-to-metal cased wells irrespective of the type of the casing, for casing-to-casing scenarios, cross-well technology at this point is limited to chromium-to-chromium scenarios.

Experience with Crosswell Electromagnetics (EM) for Waterflood Management in Oman

Beginning in 2003 Petroleum Development Oman (PDO) began testing the crosswell electromagnetic method for waterflood monitoring in Oman. The tomographic method, which determines interwell resistivity from inductive EM signals, is well suited for tracking injected water volumes, especially when this fluid is a low resistivity, high salinity brine.

A Modeling Comparison of Two Crosswell EM Systems For Water Flood Monitoring In Horizontal Wells

The crosswell electromagnetic (EM) method is intended to map resistivity distribution between wells. In this paper we simulate this method for monitoring the progress of a thin water injection plume between two open horizontal wells. First, we simulate response of a magnetic-magnetic EM system due to the lateral extent of a thin uniform 2D plume. After that, the same experiment is repeated for an electric-electric crosswell system. The inversion results for an uniform 2D plume using the electric-electric configuration are shown. In the last part, modeling the example for a 3D nonuniform fluid flow field is presented.