Earth Science Frontiers ›› 2022, Vol. 29 ›› Issue (6): 175-187.DOI: 10.13745/j.esf.sf.2022.8.18

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Formation mechanism of the Bozi-Dabei trillion cubic natural gas field, Kuqa foreland thrust belt

YANG Xuewen1(), WANG Qinghua1, LI Yong1, LÜ Xiuxiang2,3, XIE Huiwen1, WU Chao1, WANG Cuili1, WANG Xiang1, MO Tao1, WANG Rui2,3   

  1. 1. PetroChina Tarim Oilfield Company, Korla 841000, China
    2. School of Geosciences,China University of Petroleum (Beijing), Beijing 102249, China
    3. State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum (Beijing), Beijing 102249, China
  • Received:2022-07-07 Revised:2022-07-26 Online:2022-11-25 Published:2022-10-20

Abstract:

The ultra-deep layer of the Bozi-Dabei area, Kelasu structural belt, Kuqa foreland basin is a crucial oil and gas exploration area in the Tarim Oilfield with the estimated natural gas resource exceeding one trillion cubic meters. Based on cores, cast sheets, analytical assays, well logging and production data, the oil and gas sources, reservoirs and caprocks in the Bozi-Dabei area are analyzed, and subsequently the oil/gas transport and charging characteristics are systematically studied, the hydrocarbon accumulation conditions and process are analyzed, and the formation mechanism of the giant Bozi-Dabei natural gas field is clarified. The general characteristics of oil/gas accumulation are early oil accumulation, late gas accumulation, overpressure charging, vertical transport, and efficient accumulation. And the “early-stage shallow burial, late-stage rapid deep burial” regiment enables the source rocks to generate hydrocarbon continuously, while the good reservoir-cap configuration and vertical transport via faults provide the pre-conditions for oil/gas migration and accumulation. Mature to over-mature source rocks, planar-arranged and vertical-stacked traps, high-quality reservoir facies belts, and huge thick gypsum-salt caprocks are effectively superimposed in the Bozi-Dabei area to form the large high-abundance, ultra-high-pressure natural gas reservoirs.

Key words: Kuqa foreland basin, foreland thrust belt, Kelasu structural belt, high pressure, oil and gas accumulation model

CLC Number: