China Petroleum Exploration ›› 2017, Vol. 22 ›› Issue (4): 61-72.DOI: 10.3969/j.issn.1672-7703.2017.04.006

• PETROLEUM GEOLOGY • Previous Articles     Next Articles

Prospect and breakthrough point of oil and gas exploration in Baoding sag,Jizhong depression

Han Chunyuan1, Shi Yulei1, Liu Jing1, Gao Zhenghong1, Zhao Wenlong1, Luo Luyao2   

  1. 1 PetroChina Huabei Oilfield Company;
    2 Geophysics and Oil Resource Institute, Yangtze University
  • Received:2016-04-07 Revised:2017-04-25 Online:2017-07-15 Published:2017-07-14

Abstract: Based on seismic, drilling and chemical analysis data, and studies on basin development background and structural and depositional characteristics, the source rock and resource potential in the Paleogene Kongdian Formation and the fourth member of the Shahejie Formation (Sha 4 Member) in the Baoding sag, the Jizhong depression, were analyzed synthetically using logging evaluation and basin simulation techniques, and the prospect and favorable targets of oil and gas exploration were predicted. The study shows that the Baoding sag is a dustpanlike faulted depression which is faulted on the west and overlaid on the east, under the control of the fault belt on the east of the Taihang Mountain, and it has similar basin-forming background and tectonic-sedimentary evolution process as the sags on the west of the Jizhong depression, such as the Langgu sag, the Xushui sag and the Shijiazhuang sag. During the deposition of the Paleogene Kongdian Formation and Sha 4 Member, the northern part of the Baoding sag connected to the Dianbei subsag of the Baxian sag and the Xushui sag in the same confluence lake basin, where two sets of brackish semi-deep and deep lacustrine source rocks were developed, i.e. the fourth member of the Shahejie Formation-the first member of the Kongdian Formation (Sha 4-Kong 1), and the second member of the Kongdian Formation-the third member of the Kongdian Formation (Kong 2-Kong 3). The distribution area of high quality source rocks with TOC of more than 2% is 1470 km2 and 910 km2, respectively, and the thickness is 10-140 m in the subsags. The estimated oil resources and gas resources are (1.27-2.03)×108t and (270.24-333.29)×108m3 respectively in the Baoding sag, which mainly accumulate in the buried hill and the Kongdian Formation. The sag has good prospect of oil and gas exploration. In the sag, the drape anticline in the "uplift-in-sag" Qingyuan buried hill provides good accumulation conditions, which can develop into buried hill reservoirs with "new source rocks and old reservoir beds" and structural reservoirs in Kong 1 Member as favorable exploration breakthrough points.

Key words: resource potential, exploration breakthrough point, Paleogene, Baoding sag, Jizhong depression

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