Xinjiang Petroleum Geology ›› 2022, Vol. 43 ›› Issue (5): 505-512.doi: 10.7657/XJPG20220501

• OIL AND GAS EXPLORATION •     Next Articles

Accumulation Conditions and Exploration Direction of Lower Jurassic Tight Sandstone Gas Reservoirs in Taibei Sag

CHEN Xuan1(), WANG Jufeng2, XIAO Dongsheng1, LIU Juntian1(), GOU Hongguang1, ZHANG Hua1, LIN Lin1, LI Hongwei1   

  1. 1. Research Institute of Exploration and Development, Tuha Oilfield Company, PetroChina, Hami, Xinjiang 839009, China
    2. Research Institute of Petroleum Exploration and Development, PetroChina, Beijing 100083, China
  • Received:2021-12-06 Revised:2022-01-21 Online:2022-10-01 Published:2022-09-22
  • Contact: LIU Juntian E-mail:cx168@petrochina.com.cn;ljtyjy@petrochina.com.cn

Abstract:

The Turpan-Hami basin has great potential of oil and gas resources in the Lower Jurassic strata, with a large quantity of remaining resources. The discovered oil and gas reservoirs are mainly distributed in the positive structural belts around the Shengbei and Qiudong subsags in the Taibei sag, and they are primarily structural reservoirs. Less researches on the oil and gas resources in the hinterland of the subsags have been performed. Based on the dissection of known reservoirs, a systematic study was carried out on the depositional system, source rock, reservoir rock and accumulation conditions of three major hydrocarbon-rich subsags in the Taibei sag. The results show that the coal-measure source rocks are widely developed in the Shuixigou group in the Taibei sag and are in broad contact with the braided river delta sandstones, which is conducive to the formation of near-source tight sandstone gas reservoirs. There are two types of tight sandstone gas reservoirs in the Lower Jurassic, namely, trap-type and continuous-type. The hinterlands of the subsags are favorable areas for the formation of continuous-type tight sandstone gas reservoirs. Therefore, the exploration should be switched from the source-edge positive structure to the hydrocarbon-rich subsag, and from the above-source conventional oil reservoirs to the in/near-source tight sandstone gas reservoirs. The hinterlands of the Shengbei and Qiudong subsags have the conditions to form large gas reservoirs, so they are favorable areas for exploring near-source tight sandstone gas reservoirs in the lower Jurassic.

Key words: Turpan-Hami basin, Taibei sag, tight sandstone gas reservoir, hydrocarbon-generating subsag, Lower Jurassic, hydrocarbon accumulation condition, exploration potential

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