井震结合砂体构型表征及其对剩余油的控制研究:以冀东油田明化镇组NmⅢ12-1小层为例

Characterization of Sand Body Architecture by Well and Seismic Data and Remaining Oil Distribution: A Case Study in the NmⅢ12-1 Area,Minghuazhen Formation,Jidong Oilfield

冀东油田明化镇组NmⅢ12-1小层井网分布不均,但地震资料品质较好。为此,对该小层进行井震结合砂体构型表征,建立曲流河砂体构型边界的正演概念模型。利用地震沿层切片属性、反演等地震资料及测井砂体特征有效提高单一河道边界及点砂坝砂体识别精度。采用'模式拟合'对点砂坝及其内部构型进行表征,利用水平井及动态资料验证构型解剖的合理性。在此基础上,建立三维储层构型模型并进行数值模拟,预测剩余油,提出曲流河砂体控制剩余油分布。开发中后期的油藏,正向微构造、储层构型和井网是剩余油分布的主控因素。构型控制的剩余油多集中在点砂坝的中上部;废弃河道及点砂坝内侧积层对渗流产生一定的遮挡,在废弃河道附近及侧积层间的侧积体常富集剩余油。研究对油田开发方案的调整具有重要意义。

Well pattern distribution is not uniform in the NmⅢ12-1 area(Minghuazhen Formation)of the Jidong oilfield,but the quality of seismic data is good.Therefore,integration of well and seismic data method was adopted to study the sand body architecture,and conceptual models of architecture boundaries were established.The accuracy of single channel boundary and point bar sand body identification were effectively improved by combining seismic and well log data.The point bar and its internal configuration were characterized by the'mode-fitting'method,and the horizontal well and dynamic data were used to verify the results.Consequently,3 D reservoir models were established to predict the remaining oil distribution.In the middle and later stages of oilfield development,the remaining oil distribution is mainly affected by the micro-structures,reservoir architecture and well network.The positive micro-structures(e.g.micro-fault nose structure and micro-anticline),is the main site with relatively rich remaining oil.Point bar sand bodies generally have positive rhythm.Under the gravity influence,the lower part of the reservoir is substantially flooded,thus the remaining oil is concentrated mainly in the upper part.Since the abandoned channel and laterally-accreted shale beds often have certain shielding effect on the fluid flow,there are commonly plenty of remaining oil.