The Paleokarst Reservoirs of Oil/Gas Fields in China

CHEN Xue-shi; YIWan-xia; LU Wen-zhong

There widely exists paleokarst reservoir associated with regional unconformitiesduring the oil and gas exploration in China. Based on the analysis of the paleokarst reservoirs in Ordovician gas field in Ordos basin, Ordovician oil/gas field in Tarim basin and Sinian gas field in Sichuan basin, the authors have found that the paleokarst reservoirs in China are common in the following characteristics: (1) The paleokarst zone can be explicitly divided into three subzones in vertical, i.e. the surface remnant karst zone, the vertical vadose zone and the horizontal phreatic zone.(2) The reservoir space is remnant dissolved pores, vugs and fissures. The most favorable reservoir for oil and gas accumulation is the fissure-dissolved vug reservoir. (3)The distribution of paleokarst reservoirs is controlled by paleokarst morphologyand fault fissures. The most favorable place for reservoir development is on karst slopes and in fault belts.(4) Dissolution during deep burial coincides with the maturation of source rocks, hydrocarbon evolution and migration.Porosity enhancement related to the burial organic dissolution takes place just prior to the arrival of hydrocarbons in reservoirs, so it is of economic concern. (5) Karstification and burial organic dissolution are the most important diagenesis for the paleokarst reservoir development. The formeris a prerequesite factor, while the latteris adominant factorin the reservoir construction.The paleokarst reservoiris a new domain for the deep exploration of oil and gas in China.

Hangzhou Institute of Petroleum Geology, CNPC,Hangzhou 310023

Received Date: 2003-03-03

Rev Recd Date: 2003-07-02

Publish Date: 2004-06-10

Key words:

Abstract: There widely exists paleokarst reservoir associated with regional unconformitiesduring the oil and gas exploration in China. Based on the analysis of the paleokarst reservoirs in Ordovician gas field in Ordos basin, Ordovician oil/gas field in Tarim basin and Sinian gas field in Sichuan basin, the authors have found that the paleokarst reservoirs in China are common in the following characteristics: (1) The paleokarst zone can be explicitly divided into three subzones in vertical, i.e. the surface remnant karst zone, the vertical vadose zone and the horizontal phreatic zone.(2) The reservoir space is remnant dissolved pores, vugs and fissures. The most favorable reservoir for oil and gas accumulation is the fissure-dissolved vug reservoir. (3)The distribution of paleokarst reservoirs is controlled by paleokarst morphologyand fault fissures. The most favorable place for reservoir development is on karst slopes and in fault belts.(4) Dissolution during deep burial coincides with the maturation of source rocks, hydrocarbon evolution and migration.Porosity enhancement related to the burial organic dissolution takes place just prior to the arrival of hydrocarbons in reservoirs, so it is of economic concern. (5) Karstification and burial organic dissolution are the most important diagenesis for the paleokarst reservoir development. The formeris a prerequesite factor, while the latteris adominant factorin the reservoir construction.The paleokarst reservoiris a new domain for the deep exploration of oil and gas in China.

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Reference (9)

[1]	侯方浩,方少仙,董兆雄,等. 鄂尔多斯盆地中奥陶统马家沟组沉积环境与岩相发育特征. 沉积学报,2003,21(1): 106～112[Hou Fanghao, Fang Shaoxian, Dong Zhaoxiong, et al. The developmental characters of sedimentary environments and lithofacies of middle Ordovician Majiagou Formation in Ordos Basin. Acta Sedimentologica Sinica, 2003, 21(1): 106～112]
[2]	马振芳,付锁堂,陈安宁. 鄂尔多斯盆地奥陶系古风化壳气藏分布规律. 海相油气地质, 2000,5(1～2):98～102 [Ma Zhenfang, Fu Suotang, Chen Anning. Distribution regularities of Ordovician weathering-crust gas reservoirs in Ordos basin. Marine Origin Petroleum Geology, 2000, 5(1～2):98～102]
[3]	徐世琦,邓洪斌,洪海涛. 长庆气田奥陶系岩溶古地貌对气藏的控制作用. 天然气勘探与开发, 2001, 24(4): 1～5 [Xu Shiqi, Deng Hongbin, Hong Haitao. The paleokarst morphology control on the Ordovician gas reservoir, Ordos basin. Natural Gas Exploration Development, 2001, 24(4): 1～5]
[4]	阎相宾,韩振华,李永宏. 塔河油田奥陶系碳酸盐岩储层几点新认识. 海相油气地质, 2001, 6(4): 8～14 [Yan Xiangbin, Han Zhenhua, Li Yonghong. Some cognition on characteristics of Ordovician carbonate reservoir in Tahe oil fields. Marine Origin Petroleum Geology, 2001, 6(4): 8～14]
[5]	王兴志,黄继祥,侯方浩,等. 四川资阳地区及邻区灯影组古岩溶特征与储集空间. 矿物岩石, 1996, 16(2): 47～54 [Wang Xinzhi, Huang Jixiang, Hou Fanghao, et al. The relations between paleokarst and reservoir porosity in Dengying Formation,Sinian of Ziyang and neiboring area, Sichuan. Journal of Mineralogy and Petrology, 1996, 16(2): 47～54]
[6]	宋文海. 乐山-龙女寺古隆起大中型气田成藏条件研究. 天然气工业, 1996,16(增):13～26 [Song Wenhai. Research on reservoir-formed conditions of large-medium gas fields of Leshan-Longnusi paleohigh[J]. Natural Gas Industry, 1996, 16(Suppl.): 13～26]
[7]	徐世琦,张光荣. 四川盆地资阳地区震旦系气藏储层分布与控制因素. 天然气勘探与开发, 1999, 22(3):1～5 [Xu Shiqi, Zhang Guangrong. Factors affecting the reservoir distribution in Sinian gas field in Ziyang area, Sichuan. Natural Gas Exploration and Development, 1999,22(3):1～5]
[8]	王一刚,文应初,刘志坚. 川东石炭系碳酸盐岩储层孔隙演化中的古岩溶和埋藏溶解作用. 天然气工业, 1996, 16(6): 18～22 [Wang Yigang, Wen Yingchu, Liu Zhijian. Paleokarst and burial corrasion in pore evolution of Carboniferous rock reservoirs of Carboniferous in East Sichuan. Natural Gas Industry, 1996, 16(6): 18～22]
[9]	Charles Kerans. Karst-controlled reservoir heterogeneity in Ellenburger Group carbonates of West Texas. AAPG Bulletin, 1988, 72(10): 1160～1183

The Paleokarst Reservoirs of Oil/Gas Fields in China

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