基于含砂率的相控地质统计学反演储层预测技术研究

Reservoir prediction technology research of facies-controlled geostatistical inversion based on sand content rate

陆相湖盆三角洲沉积储层横向变化快、纵向薄砂泥互层,储层预测难度大.针对该问题,本文以乌石油田群流沙港组二段中层序为背景,提出了一种基于含砂率的相控地质统计学反演储层预测技术.通过单井统计,建立含砂率与沉积微相的关系;再利用平面含砂率横向约束建立三维含砂率初始模型;进而运用贝叶斯理论将三维含砂率初始模型作为约束条件融入到地质统计学反演进程中,实现了三角洲沉积相控反演技术研究.结果表明,相比常规地质统计学反演,应用该技术得到的反演结果精度大幅提升,不仅纵向分辨率高,且对不同期次砂体的叠置关系及沉积相纵、横向演变规律展现效果更好,有效指导了油田勘探开发实施.

It is difficult to predict the reservoir because of the rapid lateral change and the vertical thin sand mud interbedding of the continental lake delta sedimentary reservoir.Aiming at the problem,this paper proposes a facies-controlled geostatistical inversion reservoir prediction technique based on sand content,taking the sequence of Liushagang formation in Wushi oilfield group as background.Firstly,the relationship between sand content and sedimentary microfacies is established through single well statistics;secondly,the three-dimensional initial model of sand content is established by using horizontal constraint of plane sand content;at last,the initial model of sand content is integrated into the process of geostatistical inversion by using Bayesian theory as the constraint condition,thus realizing the research of delta sedimentary faciescontrolled inversion technology.The results show that the accuracy of the inversion results by this technique is greatly improved compared with the conventional geostatistical inversion.It not only has a high vertical resolution,but also has a better effect on the superposition of sand bodies in different periods and the vertical and horizontal evolution of sedimentary facies,which effectively guides the implementation of oilfield exploration and development.