酒西盆地油气形成与勘探方向新认识（一）——基本石油地质条件及生油潜力

酒西盆地已有半个多世纪的勘探历程，发现了6个油田，探明石油储量约1×10

New Opinions on Oil andGas Generation and Exploration in Jiuxi Basin (

Jiuxi basin has been explored for more than half a century. Six oil fields have been discovered and 1×108t OOIP has been proven in the basin. However, the petroleum exploration in the basin keeps low level up to now. Based on the new seismic data obviously different from the past,the Qingxi depression of Jiuxi basin may be divided into three tectonic units: two sags (Qingnan sag and Hongnan sag) and one uplift (Qingxi low uplift) which is sandwiched between the two sags. The Lower Cretaceous source rock in the depression mainly formed in semi-deep to deep lacustrine environment with a small area and large thickness (more than 2500m thick in both Qingnan and Hongnan sags). The main source rock is distributed in Chijinpu，Xiagou and Zhonggou Formations with organic carbon content from 1% to 2%, hydrocarbon generating potential (S1+S2) from 6mg/g to 8mg/g and chloroform bitumen “A” and total hydrocarbon content being 1.5‰ and 0.9‰, respectively. Organic matter is mainly composed of type II and type I kerogene containing rich perhydrous macerals and with high hydrocarbon potential. Being near the Hongnan sag, Qingxi low uplift is tectonically favorable for petroleum migration and accumulation,and should be the main exploration target in Jiuxi basin.