Reservoir Evaluation and Development ›› 2021, Vol. 11 ›› Issue (2): 248-255.doi: 10.13809/j.cnki.cn32-1825/te.2021.02.016

• Comprehensive Research • Previous Articles     Next Articles

Sedimentary characteristics of sandy beach-bar in faulted-lacustrine-basin, Ef3 in west slope of Qintong Sag

ZHAO Shijie1(),FU Qiang1(),LUO Weifeng2,HUANG Jianling1,TENG Ji1   

  1. 1. State Key Laboratory of Marine Geology, Tongji University, Shanghai 200092, China
    2. Research Institute of Exploration and Development, Sinopec East China Oil and Gas Company, Nanjing, Jiangsu 210011, China
  • Received:2019-11-04 Online:2021-04-26 Published:2021-04-30
  • Contact: FU Qiang E-mail:zhaoshijie9267@163.com;fuqiang@tongji.edu.cn

Abstract:

Taking the sandy beach-bar deposit in the 3rd member of Funing formation(Ef3) in the west slope zone of Qintong sag as the research object, based on core, logging and various analysis test data, the sedimentary characteristics and sedimentary dynamic conditions of the sandy beach-bar are analyzed comprehensively, the genetic types of sandy beach-bar have been divided and the main controlling factors under spatiotemporal conditions have been summarized. The research suggests that the sandy beach-bar deposits can be further divided into beach sand and bar sand, and they have great differences in lithology, color, thickness, particle size and sedimentary structure. According to the analysis of the sedimentary dynamic conditions for the formation of sandy beach-bar, the sedimentary genetic types of sandy beach-bar in the western slope belt can be divided into two types: ①the redeposited sandy beach-bar in front or side margin of far source delta, ②near-shore sandy beach-bar controlled by near-source alluvial fan. The former is found in each sand group of Ef3, and most widely distributed in Ef34 sand group. The latter is only found in Ef34 sand group, which is restricted to the southeast coast of the west slope and developed in belts. The study of sedimentary characteristics of sandy beach-bar in continental faulted lacustrine basin is of theoretical significance for the exploration and development of lithologic oil and gas reservoirs in thin interbedded lacustrine facies.

Key words: sandy beach-bar, sedimentary characteristics, sedimentary dynamics, 3rd member of Funing formation(Ef3), west slope zone, Qintong sag

CLC Number: 

  • TE121