Oil & Gas Geology ›› 2022, Vol. 43 ›› Issue (1): 92-104.doi: 10.11743/ogg20220108

• Petroleum Geology • Previous Articles     Next Articles

Controls on formation and development of large-sized high-quality dolomite reservoirs in the Tarim and Sichuan Basins

Zhanfeng Qiao1,2,3(), Shaonan Zhang1, Anjiang Shen2,3, Min She2,3, Lili Huang2,3, Wenzheng Li2,3, Guanming Shao2,3, Chuanrui Dai2   

  1. 1.State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu, Sichuan 610500, China
    2.Hangzhou Research Institute of Geology, PetroChina, Hangzhou, Zhejiang 310023, China
    3.Key Laboratory of Carbonate Reservoirs, CNPC, Hangzhou, Zhejiang 310023, China
  • Received:2020-03-30 Revised:2021-05-06 Online:2022-02-01 Published:2022-01-28

Abstract:

Following a comparative analysis of the main mechanisms and periods of dolomitization and dissolution in typical dolomite reservoirs in Tarim and Sichuan Basins,we identified the factors controlling the development of large-sized high-quality dolomite reservoirs: penecontemporaneous dolomitization is crucial to the scale of the reservoirs and dissolution modification is necessary for the quality of the reservoirs,thus the coupling of dolomitization with dissolution is the prerequisite for the development of large and high-quality dolomite reservoirs.Three geological processes that facilitate the development of the reservoirs were also brought forward: the (pene-) contemporaneous dolomitization associated with dissolution that mainly formed high-energy mound/reef-shoal and tidal-flat reservoirs against the backdrop of sea level fall; the adoptive burial dolomitization that mostly created reservoirs through shallow dolomitization of preexisting reservoirs,with quality and scale conditioned by the facies and dissolution intensity of preexisting reservoirs; and the epigenetic modification by dissolution that formed reservoirs after a hydrothermal or meteoric karstification of preexisting dolomite reservoirs,with quality and size controlled by facies,faults and unconformities as well as the development of the preexisting dolomite reservoirs.The above understandings may shed light on the prediction of large-sized deep high-quality dolomite reservoirs.

Key words: dolomite reservoir, dolomitization, burial dolomitization, deep dolomite, Tarim Basin, Sichuan Basin

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