The Whole Space Resistivity Method To Detect Finite Element Simulation Of The Reservoir Boundary

This paper taked an layered media model as background model and used finite element method as numerical simulation method, in application of the whole space resisitivity method to put the source in the space of underground and receives in the whole space. Then the electric field distribution has been analyzed which of the point current source in the layered media model which exist of oil reservoir. Finally the anomalous characteristic has been gained which of electric field distribution with the oil reservoir body in the different situation. This provide the reliable theoretical basis to explore the oil reservoir boundary by means of resisitivity method.Firstly, the paper introduces the concepts of the whole space resisitivity method and the whole space apparent resistivity. After the deduction of formula, the whole space apparent resistivity caculate formula has been gained.Secondly, through the calculation of the finite element method, the anomalous characteristic of electric field distribution and the regularity of the oil reservoir body in the layered media. On the result of the calculation, the apparent resistivity anomalous characteristic curve has been gained which of the oil reservoir body in the main section, varied depth planar, vertical profile and horizontal section in different position, in the case of the point current source's different position of the oil reservoir body (above or beneath) and the different distance to the oil reservoir body. At the same time when the oil reservoir body has the different thickness and has the different resisitivity, the apparent resistivity anomalous characteristic curve has been gained which in the main section, vertical profile and horizontal section in different position.Finally, analysis the different anomalous characteristic curve, the regulation has been gained which of the anomaly effects caused by the variety of the position of the point source and the oil reservoir body. The anomaly that the point source above the oil reservoir body is more apparent than that under the oil reservoir body. At the same time, it's normal anomaly of high resistivity of the oil reservoir body in the oil reservoir body's under space, and it's negative anomaly in the oil reservoir body's up space. The anomaly is weak when the resistivity ratio of oil reservoir and background is 2, and the bigger the ratio is the more apparent the anomaly is. When the point source' position is confined in the oil reservoir, the anomaly's range is larger,so the anomaly is apparent accordingly. While, it will not symmetrize when it is kept distances from the centre for instance, the anomaly is vary weak when the point source keeps 200m away from the edge of the oil reservoir. Above all provides basis to identify the oil reservoir's rang of distribution by means of the whole space resisitivity method.