川中龙女寺构造栖霞组薄储层预测地质模型

Thin Reservoir Prediction and Exploration Area Selection of Qixia Formation in Longnvsi Structure, Central Sichuan Basin

刘宏 王双琴 谭磊 唐松 陈聪

LIUHong WANGShuangqin TANLei TANGSong CHENCong

西南石油大学天然气地质四川省重点实验室, 四川 成都 610500 中国石油碳酸盐岩储层重点实验室西南石油大学研究分室, 四川 成都 610500 西南石油大学地球科学与技术学院, 四川 成都 610500 中国石油西南油气田公司川中油气矿, 四川 遂宁 629000 中国石油西南油气田公司勘探开发研究院, 四川 成都 610041

Provincial Key Laboratory of Natural Gas Geology, Southwest Petroleum University, Chengdu, Sichuan 610500, China Research Division of Southwest Petroleum University, Key Laboratory of Carbonate Reservoirs, CNPC, Chengdu, Sichuan 610500, China School of Geosciences and Technology, Southwest Petroleum University, Chengdu, Sichuan 610500, China Chuanzhong Oil and Gas Mine, Southwest Oil & Gas Field Company, PetroChina, Suining, Sichuan 629000, China Exploration and Development Research Institute, Southwest Oil & Gas Field Company, PetroChina, Chengdu, Sichuan 610041, China

近年来，川中地区多口井在栖霞组钻获高产工业气流，展现出该层系巨大的勘探潜力，但较之川西北台缘带，位于台内的龙女寺地区栖霞组碳酸盐岩滩体规模小，储层厚度薄，远低于地震纵向分辨率，一直未取得较好的储层预测效果，严重制约着广大台内地区的油气勘探开发。为此，针对台内地区薄储层预测难点，综合利用岩芯、薄片、测井及地震等资料，以地质地球物理紧密结合的思路，对川中龙女寺地区栖霞组储层控制因素及预测地质模型进行研究，研究结果表明，该区域栖霞组储层主要为滩相白云岩储层，储集岩以晶粒云岩、云质灰岩为主，主要储集空间为晶间（溶）孔、溶洞，可见少量裂缝。控制栖霞组相对优质储层形成的主要因素为栖霞期古地貌位置、沉积微相及断裂发育情况，据此建立了“栖霞期古地貌高地+滩核和滩缘微相区+断裂发育区”的龙女寺栖霞组薄储层预测地质模型，并在此基础之上优选出储层发育有利区，为栖霞组台内地区油气勘探部署优选有利区带提供理论支撑。

In recent years, a number of wells in central Sichuan have drilled high-yield industrial airflow in Qixia Formation, showing the great exploration potential of the strata. However, compared with the northwestern margin of Sichuan, the carbonate beach body of Qixia Formation in Longnvsi Area is smaller in scale and thinner in reservoir thickness, which is far lower than the seismic longitudinal resolution, and has not achieved good reservoir prediction effect, which seriously restricts the oil and gas exploration and development in the vast area of the platform. Therefore, in view of the difficulty in thin reservoir prediction in the platform, the reservoir control factors and prediction geological model of Qixia Formation in Longnvsi Area of central Sichuan are studied by comprehensively utilizing core and thin section, combined with logging and seismic data, and the idea of close combination of geology and geophysics. The results show that the reservoir of Qixia Formation in this area is mainly beach dolomite reservoir, and the reservoir rocks are mainly grain dolomite and dolomitic limestone. The main reservoir space is intergranular (dissolved) pores and caves, and a small amount of cracks are visible. The main factors controlling the formation of relatively high-quality reservoirs in Qixia Formation are the position of paleogeomorphology, sedimentary microfacies and fracture development in Qixia Period. Based on this, a thin reservoir prediction geological model of Longnvsi Qixia Formation in “Qixia Period paleogeomorphology highland+ shoal core and Shoal margin microfacies+fracture development area” is established, and on this basis, the favorable areas for reservoir development are optimized. The research results provide important support for the optimization of favorable zones for oil and gas exploration deployment in the platform of Qixia Formation.

10.11885/j.issn.1674-5086.2021.09.26.01