Title: Geological and geochemical analyses on accumulation conditions of shale oil and gas in Jurassic strata of the north margin of the Qaidam Basin
Abstract: In order to discuss shale oil and gas accumulation conditions and predict favorable prospect areas and exploration layers within the Lower-Middle Jurassic strata in the north margin of the Qaidam Basin, the thickness, organic geochemical characteristics, physical properties, oil and gas content of shale from the Huxishan Formation(J1h) and the Dameigou Formation(J2d) were studied systematically. The result showed that the thickness of organic-rich shale of J1 h and J2 d are large, and their TOC values are generally greater than 1.5%. The kerogen types of organic matters are mainly type Ⅱ and type Ⅲ. The maturity of organic matters varies from immature stage to over-mature stage. Brittle mineral content is approximately 50%, porosity mainly from 1% to 8%. Shales from J1 h and J2 d show strong adsorption capacity to gas, and abnormal total hydrocarbon were observed in many wells in gas logging of J1 h and J2 d shale layer. It indicates that J1 h and J2 d are essential for the formation of shale oil and gas reservoir. The Middle-Upper Group of J1 h is the favorable layer for shale oil and gas, and the favorable prospect area should be mainly located in the Lenhu No.4-5 tectonic belt. The 5th Member of J2 d is favorable layer for shale gas while the 7th Member is favorable layer for shale oil. The favorable prospect areas are mainly located in the Suganhu Depression, the Yuka Fault Depression, the Hongshan Fault Depression, the Ounan Sag, the eastern part and the southern part of the Delingha Fault Depression.
Publication Year: 2014
Publication Date: 2014-01-01
Language: en
Type: article
Access and Citation
Cited By Count: 1
AI Researcher Chatbot
Get quick answers to your questions about the article from our AI researcher chatbot