Oil & Gas Geology ›› 2019, Vol. 40 ›› Issue (4): 900-916.doi: 10.11743/ogg20190418

Previous Articles     Next Articles

Oil-sources rock correlation of Bayingebi Formation in Hari sag, Yingen-Ejinaqi Basin

Chen Zhijun1, Ma Fangxia1, Xiao Gang2, Zhang Yong2, Gao Yiwen1, Wang Xiaoduo1, Han Changchun1   

  1. 1. Reseach Institute of Yanchang petroleum(group) CO., LTD., Xi'an, Shaanxi 710075, China;
    2. No.2 Logging Company of CNPC Bohai Drilling Engineering Company Limited., Renqiu, Hebei 062552, China
  • Received:2018-07-19 Revised:2019-03-20 Online:2019-08-28 Published:2019-06-01

Abstract: In recent years, some achievements have been made in oil & gas exploration in Hari sag, Yingen-Ejinaqi basin, but the exploration here is very difficult due to its complex geological conditions.Especially, with the deepening of exploration, previous research results of oil & gas sources can not meet the needs of fine exploration research.Based on the test and analysis data of crude oil, oil sand and source rock samples, Bayingebi Formation is subdivided into three segments(K1b1, K1b2 and K1b3 from bottom to top), then the fine oil source analysis is carried out, and the distribution prediction and characteristics evaluation of the main source rocks are carried out in order to clarify the source of oil and the characteristics of the main source rocks.The results show that carbon isotopes have a good indication for oil sources in the study area, the crude oil in main oil-producing segments of K1b1 and K1b2 mainly comes from K1b1 and K1b2 source rocks, respectively.Biomarkers such as acyclic alkanes, steroids, terpenes and aromatics also indicate the same conclusion.In particular, aromatic compounds have achieved good application results in this study.The maximum thickness of effective source rocks in K1b1 is 151 m, and K1b2 is 222 m, the two sets of main source rocks both with a large thickness in the study area.As for geochemistry characteristic of source rock in K1b1, TOC averages at 0.89%, δ13C of kerogen ranges from -29.1‰ to -24.5‰, Ro from 0.60% to 2.01%, the source rocks are characterized by medium-good organic mater abundance, Type Ⅱ1-Ⅱ2 and maturity-high maturity.For source rocks in K1b2, TOC averages at 1.18%, δ13C of kerogen ranges from -30.3‰ to -23.8‰, Ro from 0.60% to 2.17%, the source rocks are good-excellent organic mater abundance, Type Ⅱ1-Ⅱ2 and maturity-high maturity source rock.With high abundance of organic matter, and in the thermal evolution stage of the peak period of hydrocarbon generation, the two sets of main source rock both have a good hydrocarbon generation potential, and can provide a good hydrocarbon basis for oil & gas accumulation.

Key words: biomarker, oil-source correlation, main source rock for hydrocarbon supply, distribution characteristics, hydrocarbon generation characteristics, Bayingebi Formation, Hari sag, Yingen-Ejinaqi basin

CLC Number: