川中地区龙王庙组油气差异聚集演化特征及其对气藏形成的影响

Differential hydrocarbon accumulation and its influence on the formation of gas reservoirs in the Longwangmiao Formation, central Sichuan Basin

林潼 谭聪 王铜山 李秋芬 冯明友 黄世伟 董景海

LIN Tong TAN Cong WANG Tongshan LI Qiufen FENG Mingyou HUANG Shiwei DONG Jinghai

中国石油勘探开发研究院, 北京 100083 西南石油大学 地球科学与技术学院, 成都 610500 大庆油田有限责任公司 勘探事业部, 黑龙江 大庆 163453

PetroChina Research Institute of Petroleum Exploration & Development, Beijing 100083, China College of Geoscience and Technology, Southwest Petroleum University, Chengdu, Sichuan 610500, China Exploration Department of Daqing Oilfield Co. Ltd., Daqing, Heilongjiang 163453, China

针对四川盆地川中地区安岳大气田龙王庙组气藏在不同构造位置上存在的显著特征差异，对整个川中构造带开展详细的气藏解剖与分析，明确了川中地区龙王庙组气藏存在着压力系统的差异、气水界面的不统一、储层沥青含量平面分布的不均以及烃类充注时间的不一致。通过对岩石矿物成岩次序厘定、包裹体拉曼成分分析、捕获温度测定、区域构造演化过程恢复，开展液态烃和气态烃的充注演化过程对比分析。结果显示：(1)川中地区存在三个明显的气藏压力系统，含气带与含水带间隔分布，从北向南气藏压力平均值逐渐降低，三个压力系统具有独立的气水界面；(2)不同含气系统中烃类的初始充注温度并不一致，早期液态烃充注的温度西高东低，具有从西向东差异聚集的演化过程；液态烃裂解时气态烃充注温度东、西构造高，中部温度略低。在气藏压力带划分和气水界面值确定的基础上，预测了不同含气系统有效气藏分布范围。

The Longwangmiao gas reservoirs have significant differences in various structural positions in the Anyue gas field of the Sichuan Basin including diversities of pressure system, gas-water interface, bitumen content and charging time. By determining the diagenetic sequence of rocks and minerals, analyzing inclusion components by Raman spectrum, calculating capture temperature, and restoring regional tectonic evolution process, comparative analyses of the charging evolution process of liquid and gas hydrocarbon were carried out. Results show that (1) Three distinct pressure systems exist in gas reservoirs in the central Sichuan Basin. Gas-bearing zones and water-bearing zones separately distributed. The average pressures of gas reservoirs decrease gradually from north to south, and the three pressure systems have independent gas-water interfaces. (2) The initial charging temperatures of hydrocarbons varied in different gas bearing systems.The temperature during liquid hydrocarbon charging was higher in the west and lower in the east, and the accumulation evolution process was different from west to east. The charging temperature during liquid hydrocarbon cracking of gaseous hydrocarbon was higher in the east and west, and slightly lower in the middle. Based on the division of pressure zones of the Longwangmiao gas reservoir and the determination of gas-water boundary value, the distribution range of effective gas reservoirs was predicted for different gas-bearing systems, which provided guidance for further exploration and deployment.

国家油气科技重大专项 2017ZX05008006-001;中国石油天然气股份有限公司前瞻性与基础性重大科技项目 2021DJ0605

https://doi.org/10.11781/sysydz202204655