Petroleum Electromagnetic Prospecting Advances and Case Studies in China

Abstract

Remarkable progress has been made in electromagnetic (EM) techniques as applied to the petroleum industry in instruments, data acquisition, and processing and interpretation in China. Included here is equipment, such as high-power Controlled Source EM (CSEM) acquisition systems, acquisition methods, such as the three dimensional small-bin Continuous Electromagnetic Array acquisition method, Time and Frequency Domain Controlled Source Electromagnetic, Borehole-to-surface Electromagnetic technique and marine magnetotelluric method. Data processing methods, such as fast three dimensional inversion using nonlinear conjugate gradients, and data interpretation methods, like Induced Polarization and Resistivity anomalies for hydrocarbon detection, are also included. These new techniques have been applied in petroleum survey and many cases are in complicated areas. They have successfully served the investigation of deep igneous rock reservoirs, and prediction of potential hydrocarbon targets. The cases indicate that electromagnetic techniques can help seismic survey to effectively detect hydrocarbon reservoir and remarkably improve drilling successes.

EM telemetry assessment for horizontal drilling in part of the Tarim basin through numerical simulation

“…We used a horizontal well having a combined conductivity of 10 6 S/m (casing effect is neglected), and air layer with conductivity of 10 5 Ωm. Subsurface resistivity model was built using resistivity log data (Rxo and Rt) from part of Tarim basin and previous surface to surface studies (He et al, 2010, Tian et al, 2017. 2D and 3D simulations for borehole source with dipole moment of 40 Am, at true vertical depth (TVD) of 6500 m and 5400 m and horizontal distance of 2500 m and 1000 m, for 2D and 3D models, respectively were carried out (Figure 1).…”

First Borehole to Surface Electromagnetic Survey in KSA: Reservoir Mapping and Monitoring at a New Scale

“…The BSEM method was first employed in Russia at the beginning of the millennium and has been extensively improved in the recent years in China, obtaining positive results (He et al, 2005(He et al, & 2010. In BSEM, the transmitting electrode is located in a wellbore and the receiver arrays are constituted by hundreds of electrodes, placed at the surface, buried a few feet under the ground (Figure 1 and Figure 2).…”

Field test of monitoring gas reservoir development using time-lapse continuous electromagnetic profile method

“…Recently, EM methods have been widely used for oil exploration (Dong et al, 2008;He et al, 2010aHe et al, , 2010b. It is well known that EM methods are more sensitive to the variation of underground fluids (such as oil and gas) than are seismic methods, so many experts in oil-field development and production hope to use time-lapse EM methods to delineate and monitor the residual oil and gas scope.…”

“…One EM method, MT, is effective in the exploration of sedimentary basins (Vozoff, 1972). After its development and improvement for decades, MT has already played an important role in oil-gas detection (He et al, 2010a). However, MT methods have several disadvantages.…”