The Control Effect of Gypsum-salt Rocks on Formation and Distribution of Overpressure: A case of Shizigou area, Qaidam Basin
doi: 10.14027/j.cnki.cjxb.2016.03.014
- Received Date: 2015-06-19
- Rev Recd Date: 2015-09-29
- Publish Date: 2016-06-10
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Key words:
- gypsum-salt rock /
- overpressure /
- Qaidam Basin /
- petroleum exploration
Abstract: Overpressure influence and control of oil and gas reservoir distribution, there is obvious relationship between overpressure distribution and development of gypsum-salt rocks. Study on the development of gypsum-salt rocks in Shizigou area, analysis of regularity of distribution of formation pressure with actual and computational data to the area, for discussing the relationship between gypsum-salt rocks and formation pressure. Gypsum-salt rocks have four sedimentary sequences in the vertical, they were inversely proportional relationship with sandstone, and were proportional relationship with mudstone in the lateral. The formation pressure has the feature of segmentation in the vertical: Ordinary pressure section, pressure coefficient range in 0.9~1.2, it's in up-salt zone; Boost pressure section, pressure coefficient range in 1.3~1.8, it's in inter-salt zone; Excess pressure section, pressure coefficient above 1.8, it's in pre-salt zone. The undeveloped area of gypsum-salt rocks have no this kind of segmentation. Pressure range covered the development range of gypsum-salt rocks. Overpressure decreased as gypsum-salt rocks thickness thinning. Gypsum-salt rocks have obvious control effect for overpressure distribution. Dewatering, compactness, plasticity, flowability, and high thermal conductivity of gypsum-salt rocks are the root cause of formation of overpressure.
Citation: | ZHANG JinNing, ZHANG JinGong, YANG QianZheng, WU ChunYan, CUI Qiang, WANG Ye, GUO Ling. The Control Effect of Gypsum-salt Rocks on Formation and Distribution of Overpressure: A case of Shizigou area, Qaidam Basin[J]. Acta Sedimentologica Sinica, 2016, 34(3): 563-570. doi: 10.14027/j.cnki.cjxb.2016.03.014 |