渭北油田长3油藏高产井地质与地震有利模式及应用

Geology and geophysical beneficial model of high yielding wells and its application in Chang 3 reservoir, Weibei Oilfield

渭北油田延长组长3油藏属浅层超低渗油藏,地层压力低且单井产量递减快,难以实现规模有效开发。为进一步明确局部高产特征,预测可开发"甜点"区,利用已知井的沉积微相、储层评价、三维地震和生产资料,重点对比分析了研究区高、中、低产井的地质和地震特征及差异。研究结果表明:高产井的地质特征为辫状河三角洲水下分流河道沉积,油层厚度大,物性及含油性好、与邻井连通性好;三维地震反射结构为连续中弱波峰振幅反射。以此对长3油藏有利储层展布及砂体连通性进行预测,在此基础上,形成了长3油藏高产井地质与地震有利模式,有效地预测了局部高产有利区带,为开发先导试验区井位优化部署,以及外围优质储量的落实提供了技术支撑。

Chang 3 reservoir of Yanchang Formation, Weibei Oilfield, is a typical shallow and ultra-low permeability reservoir with low formation pressure and rapid decline rate, which is difficult to achieve effective development on large-scale. To ascertain the characteristics of local high yielding wells and predict more favorable area, the sedimentation, reservoir evaluation, 3D seismic and production data are used to analyze the different geology and geophysical characteristics of Chang 3 reservoir. The results show that its geological characteristics are of subaqueous distributary channel with thick oil layers, high permeability, high oil saturation and great reservoir connectivity; its 3D seismic characteristic is continuous and medium tenacity amplitude reflection configuration. Based on these, Chang 3 beneficial reservoir and sand body connectivity are predicted efficiently. The high yielding beneficial model for Chang3 reservoir is established by geology and 3D seismic technology, which can efficiently predict Chang 3 high yielding area. This not only optimizes development well design in the pilot test area, but also provides technical support for high quality reserves confirmation.