惠民凹陷营子街地区深层致密砂岩储层含油性预测

惠民凹陷营子街地区致密砂岩储层埋深大,岩性、物性横向变化快,油水关系复杂,应用传统的叠后油气检测方法进行含油性识别的精度低,可靠性差。针对研究区致密砂岩储层特征,提出了储层含油性叠前综合预测方法。即根据研究区实际地质情况,优选岩石骨架混合方法,建立合理的岩石物理模型,估算井的横波速度;通过岩石物理分析,筛选出对该区致密砂岩油藏敏感的弹性参数组合(纵横波速度比和纵波阻抗),并确定区分油水层的门槛值;综合利用研究区高精度三维地震资料叠前CIP道集、层位解释数据及井资料等进行叠前弹性阻抗反演,得到敏感弹性参数融合数据体,结合油水层门槛值对研究区致密砂岩储层进行含油性预测。上述方法预测结果与实钻结果吻合率达到87%,预测有利含油面积16 km²,后钻评价井验证了预测结果的正确性和可靠性。

The burial depth of tight sandstone reservoir is large in the Yingzijie area of Huiming Sag.Lateral variation of lithology and physical property is sharp and oil-water relation is complicate.Therefore,the oil-bearing detecting based on the ordinary poststack hydrocarbon detection method in this area is of low accuracy and poor reliability.In this paper,we propose a comprehensive prestack method to detect the oil-bearing properties of tight reservoir in this area.According to the actual geological conditions in the study area,we build rational petrophysics model and estimate S-wave velocity of wells by optimized rock matrix hybrid approach.Based on the petrophysics analysis,the elastic parameters that are sensitive to tight sandstone reservoir are selected as the ratio of P-wave velocity to S-wave velocity and the P-wave impedance.The thresholds that is to distinguish oil-water layers is determined.Comprehensive utilization of CIP gathers from 3D high-precion prestack seismic data,horizon interpretation data and well data,prestack elastic impedance inversion is conducted and as a result integrated data volume of elastic parameters sensitive to tight sandstone reservoir is derived.We predict the oil-bearing properties of tight reservoir in the study area by integrating the thresholds of oil and water layer.The matching rate of predition results to the real drilling reaches 87% and potential tight sandstone reservoir can range up to 16 km2 .The posteriori drilling results prove this prediction result is accurate and effective relatively.