淡水湖相页岩小层精细划分及地球化学特征——以四川盆地侏罗系大安寨段为例

Stratigraphic division and geochemical characteristics of freshwater lacustrine shale: a case study of Jurassic Da'anzhai Section, Sichuan Basin

王玮 黄东 易海永 赵容容 岑永静 李育聪

WANG Wei HUANG Dong YI Haiyong ZHAO Rongrong CEN Yongjing LI Yucong

1. 油气藏地质及开发工程国家重点实验室(成都理工大学), 成都 610059; 2. 中国石油 西南油气田公司 勘探开发研究院, 成都 610400; 3. 中国石油 西南油气田公司 油气资源处, 成都 610400

1. State Key Laboratory of Oil and Gas Reservoir Geology and Development Engineering, Chengdu University of Technology, Chengdu, Sichuan 610059, China; 2. Exploration and Development Institute, PetroChina Southwest Oil and Gas Field Company, Chengdu, Sichuan 610400, China; 3. Oil Resources Office, PetroChina Southwest Oil and Gas Company, Chengdu, Sichuan 610400, China

通过岩性、电性、旋回特征以及页岩地球化学数据分析，对四川盆地侏罗系自流井组大安寨段湖相页岩进行了小层精细划分和资源潜力评价。大安寨段页岩自下而上划分为3个小层，其中大一三c小层主要发育滨—浅湖相块状泥页岩，横向变化大，有机质类型主要为偏腐殖型的Ⅱ2型干酪根，平均有机碳含量在1%左右，平均S1含量为0.8 mg/g；大一三b小层主要发育半深湖相页岩夹薄层介壳灰岩条带，厚度分布稳定，有机质类型主要为偏腐泥型的Ⅱ1型干酪根，平均有机碳含量大于1.5%，平均S1含量为1.18 mg/g；大一三a小层主要发育浅湖相页岩夹中—薄层介壳灰岩，有机质类型主要为偏腐泥型的Ⅱ2型干酪根，平均有机碳含量为1%～1.5%，平均S1含量为1.21 mg/g。结合地质特征、资金、技术条件以及勘探成效，认为川中北部公山庙地区的大一三a和大一三b小层，可以作为湖相页岩油气先导试验区的工作对象。

The fine division and resource potential evaluation of lacustrine shale in the Da'anzhai Section of the Jurassic Ziliujing Formation in the Sichuan Basin were made based on lithologic, electrical, cyclic characteristic and shale geochemical data. The Da'anzhai Section was divided into three sub-sections, Da 1, Da 1 3 and Da 3, from top to bottom. The Da 1 3 sub-section was further divided into three sub-layers, Da 1 3 a, Da 1 3 b and Da 1 3 c, from top to bottom. The Da 1 3 c sub-layer mainly developed shore-shallow lake block shale, with large lateral changes. The organic matter is mainly the humic type Ⅱ2 kerogen. The average organic carbon content is about 1%, and the average Rock-Eval S1 content is 0.8 mg HC/g rock. The Da 1 3 b sub-layer mainly developed semi-deep lacustrine shale with thin layers of dielectric limestone, showing a stable thickness. The organic matter is mainly type II1 kerogen with partial gel type. The average organic carbon content is more than 1.5%, and the average S1 content is 1.18 mg/g. The Da 1 3 a sub-layer mainly developed shallow lacustrine shale with normal and thin dielectric limestone. The organic matter is mainly type II2 kerogen with partial gel type. The average organic carbon content is 1% to 1.5%, and the average S1 content is 1.21 mg/g. Based on current geological characteristics, funds, technical conditions and exploration results, it was proposed to open up a pilot test area of lacustrine shale oil and gas in the Gongshan Temple area in central and northern Sichuan Province, and concentrate on the Da 1 3 a and Da 1 3 b sub-layers.

“十三五”国家科技重大专项“四川盆地致密油资源潜力、甜点区预测与关键技术应用”（2016ZX05046006-008）资助。

https://doi.org/10.11781/sysydz201905724