Application Research of Crosshole Electromagnetic Tomography

Abstract

[Abstract] The main technological objective of crosshole EM tomography is to realize direct electrical measurements between wells and acquire 2D or 3D resistivity images reflecting hydrocarbon and water distribution between wells. A co-operation and joint study between The Shengli Oilfield and EMI for the application method of the crosshole EM system has been on-going since 1997. The co-operation is comprised of the following components: further examination the performance of the tools used for EM tomography, explicit improvement direction, analysis of the adaptability and feasibility to reservoir research through large-scale systematic field tests on large well separation; acceleration of the development of a processing and interpretation method as well as the software used for this method based on systematic field data; the continuation of systematic tests in steel-cased boreholes, and exploration of the resistivity imaging method in the condition of steel-casing. In November 1998, and June and July 1999, large-scale industrial field tests with 10 measurements in 3 pairs of wells were successfully conducted in the low resistivity profile in the Shengli Oilfield. First,the formation was typical of low resistivity profiles, the background resistivity being only 1.5-2.0 Ωm. The attenuation of the EM energy in the formation is very serious. Second, the field tests were conducted systematically, passing through one and two steel-casings. The desired goals were achieved in the three tests. Not only was the performance of the tools proven to be stable and reliable, but also complete crosshole EM data with good repeatability and accuracy was acquired between the wells with the separation of 434 m from open-hole to openhole and 150m from open-hole to casing-hole for the first time ever. The resistivity images derived from the data inversion shows good geological results in the analysis of hydrocarbon distribution and reservoir recovery states between wells.

The Problem and Countermeasures of Environmental Pollution in Food Industrializing Process

“…2.1 Soil and water loss: in many places, in order to solve the problem that the large percentage of mountain and slope and meet the needs of large-scale cultivation, the "terracing" was used as the main method of the farmland construction [7] .But because of non-scientific cultivation, the original soil was destructed and the good soil turned into rare soil. In addition, the vegetation environment changed, soil eroded and new soil and water loss appeared.…”

Application of 2.5D cross-hole electromagnetic inversion in Gudao Oil Field, East China

“…In 1997, Shengli oil field in East China, in cooperation with the EMI Company, carried out a large scale pilot test of cross-hole EM measurement. The objective of the test was to examine the feasibility of applying the cross-hole EM measurements to locate high residual oil concentration zones which have relatively high resistivity (Zeng et al, 2001).…”