油层注聚后测井曲线异常及水淹层解释校正

Well logging curve anomaly and watered-out oil layer interpretation correcting method after polymer flooding

针对注聚区块新钻井水淹层解释异常的问题,通过注聚前后的测井曲线资料对比和取心井资料分析,研究了注聚后储层特征和测井响应的变化规律,发现深三侧向等电阻率曲线值没有因水淹影响而降低,反而升高;自然电位曲线幅度值减小。测井曲线异常变化对测井解释的影响主要表现为水淹程度偏低,综合注聚前后储层特征变化和聚驱油层岩石电性特征研究,归结出聚合物在孔隙中的滞留是引起测井响应变化的主要原因。研究建立了测井响应异常的判别公式、测井响应复原图版和水淹层解释校正方法,使注聚后水淹层解释精度达到了85%,较原方法提高了20个百分点。研究成果在喇嘛甸油田得到推广应用,为聚驱效果评价、聚驱后剩余油研究与挖潜提供了可靠依据。

In views of the problem of watered-out layer interpretation anomaly for newly-drilled well in the block of polymer flooding, through comparing of well logging data between before and after polymer flooding and even the analysis of cored well data, the paper studies the changing laws of reservoir characteristics and well logging response after polymer flooding, and then discovers that the value of resistance curve of deep three-lateral logging is not reduced by water flooding but increased on the contrary; amplitude values of spontaneous potential logs lower down a bit. The influence of well logging anomaly on logging interpretation displays as follows ： the degree of water flooding is rather lower. By integrating with reservoir characteristics changes before and after polymer flooding and the studies of rock electricity features of polymer flooded oil layer, the principal reason causing well logging response change is the remained polymer in pores. Through the above studies, the identifying formula of logging response anomaly, resetting map plate of well logging response and watered-out layer interpretation correcting method have been established, so the interpretation accuracy after polymer flooding has reached 85% , increasing 20% than before. The research results have been popularized in Lamadian Oilfield and furthermore have provided reliable evidence for polymer flooding effects, residual oil study after polymer flooding and the oil tapping.