Reservoir Evaluation and Development ›› 2022, Vol. 12 ›› Issue (1): 107-118.doi: 10.13809/j.cnki.cn32-1825/te.2022.01.009

• Shale Gas • Previous Articles     Next Articles

Sedimentary characteristics and favorable facies of Lower Cambrian Shale in the northern margin of Mount Daba: A case study of Maoba Outcrop in Ziyang

ZHANG Ye1,2(),YU Chuan1,2(),ZHANG Zhiping1,2,WEI Guodong3,ZHANG Hualian1,2   

  1. 1. National Joint Engineering Research Center for Shale Gas Exploration and Development, Chongqing Institute of Geology and Mineral Resources, Chongqing 401120, China
    2. Key Laboratory of Shale Gas Exploration, Ministry of Natural Resources, Chongqing Institute of Geology and Mineral Resources, Chongqing 401120, China
    3. School of Geoscience and Technology, Southwest Petroleum University, Chengdu, Sichuan 610500, China
  • Received:2021-03-22 Online:2022-02-26 Published:2022-03-24
  • Contact: YU Chuan E-mail:zhangye_sg@vip.163.com;yuchuan03041512@aliyun.com

Abstract:

The drilling of Lower Cambrian shale gas in the northern margin of Mount Daba shows good prospect. A set of dark shale strata are generally developed in the lower Cambrian in this area, but the stratigraphic heterogeneity is strong, and the sedimentary facies change obviously in the region. It is helpful for the further exploration and development to the study shale sedimentary characteristics of the Lower Cambrian in this area and analyze its influence on the differential enrichment of organic matter. On the basis of outcrop section in Maoba of Ziyang and experimental data, the researches are carried out from three aspects: the division and correlation of sedimentary facies, the analysis of sedimentary mode and the analysis of favorable sedimentary facies zones. The Lower Cambrian in the study area can be divided into four sedimentary subfacies: sub abyssal rifting trough basin facies, deep water shelf facies, shallow water shelf facies, and platform edge slope facies. Longitudinally, the water body changes from deep to shallow, and the contents of carbonaceous and siliceous gradually decrease, while the contents of clayey and carbonate gradually increase. The dark mud shale developed in the lower Cambrian Lujiaping Formation deep water shelf facies in Langao-Zhenping stratigraphic district has the larger thickness and higher content of total organic carbon and brittle minerals, which is a favorable sedimentary facies belt for the development of high-quality shale.

Key words: northern margin of Mount Daba, Lower Cambrian, sedimentary mode, shale gas, differential enrichment

CLC Number: 

  • TE122