湖相泥页岩基质储层直井压裂选层方法研究——以松辽盆地三肇凹陷松页油3井为例

湖相泥页岩基质储层是中国页岩油赋存的主要载体,相对于夹层型和裂缝型储层更难被压裂改造和实现工业开发,因而压裂层位的选择至关重要. 本文以松辽盆地三肇凹陷松页油3井为例,建立了一套湖相泥页岩基质储层直井压裂选层方法. 通过录井、测井解释优选出青山口组一段中的I类页岩油层,对I类页岩油层的电性、物性、含油气性、烃源岩性、脆性、可压性6项指标进行综合分析,基于上述6项指标,利用层次分析法对所有I类页岩油层进行综合排序,确定了27、25和23号层为最有利页岩油层. 松页油3井针对上述页岩油层进行了压裂试油,实现了三肇凹陷页岩油工业油流突破,证实选层方法可行有效,可推广应用于湖相基质型页岩油的甜点层优选和水平井部署.

FRACTURING LAYER SELECTION FOR VERTICAL WELL IN LACUSTRINE SHALE MATRIX RESERVOIR: A Case Study of SYY3 Well in Sanzhao Sag of Songliao Basin

The lacustrine shale matrix reservoir is the main carrier for shale oil in China, but it is more difficult for fracturing reformation and industrial development compared with interlayered and fractured reservoirs. Therefore, the selection of fracturing layers is of vital importance. Taking the SYY3 well in Sanzhao sag of Songliao Basin as an example, the paper establishes a set of fracturing layer selection method for vertical wells in lacustrine shale matrix reservoir. First, the Type I shale oil reservoir in the 1st member of Qingshankou Formation in SYY3 well is optimized by well logging and interpretation data. Then 6 indicators including electrical property, physical property, oil-gas possibility, source rock lithology, brittleness and fracability of Type I shale oil reservoir are comprehensively analyzed. Finally, the comprehensive ranking of Type I shale oil reservoir is conducted by analytic hierarchy process based on the above 6 indicators, and Nos. 27, 25 and 23 layers are determined as the most favorable shale oil reservoirs. Fracturing and oil testing of the above shale oil reservoirs are performed in SYY3 well, which has achieved a breakthrough in the industrial oil flow of shale oil in Sanzhao sag. It is proved that the method is feasible and effective, and can be applied to the optimization of sweet spot layer and horizontal well deployment of lacustrine matrix shale oil.