Oil & Gas Geology ›› 2011, Vol. 32 ›› Issue (6): 815-822,838.doi: 10.11743/ogg20110602

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Petroleum exploration prospect of the Jurassic tight reservoirs in central Sichuan Basin

Liao Qunshan1,2, Hu Hua3, Lin Jianping4, Liu Zhongliang1, Mu Xianzhong1   

  1. 1. Beijing University of Technology, Beijing 100124, China;
    2. CNPC Advisory Center, Beijing 100724, China;
    3. Exploration Business Division, CNPC Southwest Oil/Gas field, Chengdu, Sichuan 61004, China;
    4. Petroleum Resource Plant of Central Part of Sichuan, CNPC Southwest Oil/Gas field, Suining, Sichuan 629001, China
  • Received:2011-10-01 Online:2011-12-28 Published:2012-02-08

Abstract:

From viewpoint of continuous petroleum accumulation and comparison with Bakken Formation in Willsiton Basin(USA),the paper discussed petroleum exploration prospect of the Jurassic tight reservoirs in central Sichuan Basin.The Jurassic reservoirs in Sichuan Basin are typical tight ones with an average porosity of 1-3.7%,average permeability of 0.35×10-3-0.53×10-3 μm and median pore throat radius of 0.05-0.24 mm.The Jurassic reservoirs contacte closely with source rocks both laterally and vertically in central Sichuan Basin.The hydrocarbons accumulates within source rocks or in reservoirs close to the source rocks.The major reservoirs are continuously distributed in the slope area and sags,have no distinct trap boundaries,and are not controlled by local structures.Multiple reservoirs superimposed vertically and connected laterally,forming a large hydrocarbon-bearing areal extent.Most oil-bearing blocks have an abnormal overpressure system,no water in the reservoir and no uniform oil/water contact.The Jurassic oil accumulation in central Sichuan Basin is a typical continuous one basically similar to the Bakken Formation.In recent years,the Bakken tight oil have been deve- loped in large scale with horizontal well and multi-stage fracturing techniques thanks to the relatively high oil price.In contrast,exploration and development of the Jurassic tight reservoirs in central Sichuan Basin have no breakthrough due to the constraints of understanding,investment and technology.Improving geological understanding,strengthening research of key technologies such as horizontal drilling and multi-stage fracturing and increasing single well production are critical to the successful exploration and development of the Jurassic tight re- servoir in central part of Sichuan Basin.

Key words: multi-stage fracturing, horizontal well, continuous petroleum accumulation, exploration prospect, tight reservoir, Jurassic, Sichuan Basin

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