四川盆地北缘上二叠统大隆组烃源岩评价

EVALUATION ON DALONG FORMATION SOURCE ROCK IN THE NORTH SICHUAN BASIN

付小东 秦建中 腾格尔 王小芳

Fu Xiaodon Qin Jianzhong Tenger Wang xiaofang

中国石油化工股份有限公司, 石油勘探开发研究院, 无锡石油地质研究所, 江苏, 无锡, 214151 2. 中国石油, 杭州地质研究院, 杭州, 310023

Wuxi Research Institute of Petroleum Geology, SINOPEC, Wuxi, Jiangsu 214151, China 2. Hangzhou Institute of Petroleum Geology, PetroChina, Hangzhou, Zhejiang 310023, China

四川盆地北缘上二叠统大隆组泥质、硅质岩有机质丰度高、有机质类型较好,是一套局部发育的海相优质烃源岩。大隆组在不同剖面有机质成熟度变化较大,盆地内河坝1井处已达过成熟阶段,而盆地边缘广元、万源地区则处于低成熟—中等成熟阶段。大隆组烃源岩各剖面累计生烃强度大多小于20×108m3。川东北地区大隆组烃源岩与长兴—飞仙关组礁滩相储层有利的时空配置,可使大隆组来源的天然气更有效地在礁滩相优质储层中聚集成藏,对普光等大中型气田有较大贡献;相对于其它海相层系烃源岩,大隆组主生烃期更晚,有利于天然气后期保存。广元、万源等大隆组仍处于低—中等成熟阶段地区是否存在源自大隆组的残余油藏值得关注。

The argillaceous and siliceous rocks in the Dalong Formation of Upper Permian in the north Sichuan Basin are excellent marine source rocks with high organic matter abundance and good organic matter type. The maturity of Dalong Formation changes greatly,which reach over-mature stage in Well Heba1 section while still in low-middle mature satge in Guangyuan and Wanyan areas localed in edge of the basin. The hydrocarbon-generation intensity of Dalong Formation source rocks is mainly lower than 20×108 m3/km2. There is a good time-space matching relationship between the source rock in Dalong Formation and the excellent reef and shoal facies reservoirs in Changxing-Feixianuan Formations,which result in the oil and gas origined form Dalong Formation accumulated in the excellent reservior more efficiently and make great contribution to the large and medium-sized gas fields such as Puguang. Related to the marine source rocks in other geological periods, main hydrocarbon-generation periods of Dalong Formation source rocks is later and that is beneficial to the preservation of gas reservoir. Is there any residual oil pool in Guangyuan and Wanyuan areas where Dalong Formation is still in low-middle maturity, which is worth of particular attention.

国家重点基础研究发展计划(973计划)“中国海相碳酸盐岩层系生烃条件与生烃史分析”(2005CB422102);石油化工联合基金“地质环境及生物演化与海相优质烃源岩形成”(40839910)共同资助

https://doi.org/10.11781/sysydz201006566