塔里木盆地奥陶系碳酸盐岩大型缝洞集合体定量描述

Quantitative characterization of Ordovician carbonate fracture-cavity aggregate in Tarim Basin

大型缝洞集合体的定量描述是在中低丰度缝洞型碳酸盐岩储层中实现少井高效开发的重要手段。缝洞型碳酸盐岩储层复杂、多期的地质成因及其内部强烈的非均质性,使得常规建模手段难以直接应用于该类储层。以塔里木盆地哈拉哈塘油田典型区块为例,结合地质体特征和地震相分析,运用聚类分析方法,实现了大型缝洞集合体的几何结构建模;针对缝洞型碳酸盐岩储层测井资料少、内部结构复杂和非均质性强的特点,将地质统计学地震反演技术应用于储层岩相和孔隙度建模中,建立了哈拉哈塘油田缝洞集合体静态模型,实现了对其的定量地震描述;进一步利用单井与井组内动态数据,修正大型缝洞集合体模型的规模、边界和连通性,完成了对大型缝洞集合体的动静态精细刻画。研究成果指导了基于大型缝洞集合体的井位部署及开发。

Quantitative characterization of large fracture-cavity aggregate is the key method for efficient development of medium-low abundance fracture-cavity reservoir with fewer wells. Carbonate fracture-cavity reservoir is characterized by complex structure, multi-stage geologic origin and strong heterogeneity, which makes it difficult to develop by conventional modeling means. Taking typical block in Halahatang Oilfield in Ordos Basin as an example, combined with geologic features and seismic facies analysis, this paper used cluster analysis method to carry out geometric modeling of large fracture-cavity aggregate. Considering the lack of well logging data, complicated inner texture and strong heterogeneity of carbonate fracture-cavity reservoir, we applied geostatistical inversion technology to the reservoir lithofacies and porosity modeling, established static model of fracture-cavity aggregate for Halahatang Oilfield, and carried out the quantitative characterization. Furthermore, modified the size, boundary and connectivity of the large fracture-cavity aggregate model by dynamic data from single well and multiple wells, and completed the fine characterization. The study result can guide the drilling site design and development.