井—地电法在黄土塬油藏评价中的应用

Application of Surface-Borehole Electrical Approach to Reservoir Evaluation in Loess Tableland Area

鄂尔多斯盆地中生界陆相地层变化快,油藏类型以特低渗岩性油藏为主,隐蔽性强,受复杂的黄土塬地貌影响,评价手段相对单一。针对黄土塬地表高低起伏大、黄土层电导率低等困难,采取了地表高程静校正、静态位移校正、不规则测网布线、增大激发强度等4项措施,对井—地电法技术进行了改进。将其应用在油藏规模预测中,表现出较好的适应性,预测范围由原来的9km2增加到25～36km2,同时预测结果可靠,具有一定的推广前景。

Influenced by the complicated geomorphology of the loess tableland area,the approach for evaluating the reservoir of the area is relatively simplistic because the Mesozoic terrestrial formation of Ordos Basin changes rapidly and reservoir types are mainly lithological reservoirs featuring in extra-low permeability and great difficulty to be discovered.In view of the problems of tough surface relief of the area and low conductivity of loess,four solutions are taken to improve the surface-borehole electrical approach,that is,the surface elevations static correction,the static displacement correction,the irregular network routing,and the increment of excitation intensity.The new approach is applied to predict the size of reservoirs and good results are obtained.The prediction range increases to 25～36 km2 from 9 km2.What's more,the prediction result is reliable and has broad prospect for popularization.