东海低渗储层非均质性评价技术研究及应用

Research and Application of Heterogeneity Evaluation Technology for Low Permeability Reservoirs in the East China Sea

夏瑜 高红艳 秦德文 刘创新 单理军

XIA Yu GAO Hongyan Qin Dewen Liu Chuangxin Shan Lijun

中海石油（中国）有限公司上海分公司，上海　200030

Shanghai Branch of CNOOC(China) Ltd., Shanghai 200030, China

东海油气田近几年实施了十余井次的压裂改造，但总体上效果不好，仅少量井压后获得商业产能，分析原因认为与储层的非均质性认识不清有关。针对研究区储层埋藏深、砂体横向变化快、非均质性强等难点，提出了一套适合本区地质非均质性评价的方法：首先在AVO岩性敏感属性分析的基础上，创新建立分频滤波技术，预测有利砂体的分布区域，刻画砂体的平面横向展布特征；其次基于微观孔隙结构评价低渗储层渗透率，结合成像测井资料评价储层纵向的非均质性，优选出均质性较好的层段。该方法提高了储层的空间分辨率，能更准确预测砂体的展布特征，有效评价储层非均质性。研究表明该技术在某井应用效果较好，水平段实现了100%的砂岩钻遇率，为井轨迹优化及压裂方案设计提供了重要依据。

In recent years, more than ten times of well fracturing treatment have been implemented in the Oil and Gas Fields of East China Sea. However, the overall effect is not well with only a few wells obtaining commercial productivity after fracturing. Analysis shows that it is related to unclear understanding of reservoir heterogeneity. Aiming at the difficulties of deep reservoir burial, rapid lateral change of sand bodies, and strong heterogeneity in the study area, a suitable method for the evaluation of geological heterogeneity in this area is proposed. Firstly, based on the analysis of AVO lithology sensitivity attributes, innovative frequency-division filtering technology is used to predict the distribution area of favorable sand bodies and characterize the horizontal distribution of sand bodies. Secondly, evaluation of permeability of low permeability reservoir is based on micro pore structure analysis, combining imaging logging data to evaluate vertical heterogeneity. Consequently, well interval design with good homogeneity can be optimized. This method can improve the spatial resolution of reservoir and predict the sand body distribution characteristics more accurately, which can effectively evaluate reservoir heterogeneity. The research shows that the technology has a good application effect in a well, and the horizontal section achieves 100% sandstone drilling rate, which provides an important basis for well trajectory optimization and fracturing scheme design.

“十三五”国家科技重大专项“东海深层低渗-致密天然气勘探开发技术”（2016ZX05027-003）

https://doi.org/10.3969/j.issn.1008-2336.2020.04.007