Oil & Gas Geology ›› 2019, Vol. 40 ›› Issue (3): 571-582.doi: 10.11743/ogg20190312

• Petroleum Geology • Previous Articles     Next Articles

Experimental procedures of well-site geological evaluation for shale oil and related technological progress

Jiang Qigui1,2,3,4, Li Maowen1,2,3,4, Qian Menhui1,2,3,4, Bao Yunjie1,2,3,4, Liu Peng1,2,3,4, Tao Guoliang1,2,3,4, Ma Xiaoxiao1, Li Zhiming1,2,3,4, Cao Tingting1,2,3,4, Wu Shiqiang5   

  1. 1. Wuxi Research Institute of Petroleum Geology, Petroleum Exploration and Production Research Institute, SINOPEC, Wuxi, Jiangsu 214126, China;
    2. State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Effective Development, Wuxi, Jiangsu 214126, China;
    3. State Energy Center for Shale Oil Research and Development, Beijing 100083, China;
    4. Key Laboratory of Petroleum Accumulation Mechanisms, SINOPEC, Wuxi, Jiangsu 214126, China;
    5. Research Institute of Exploration and Development, Jianghan Oilfield Branch Company, SINOPEC, Wuhan, Hubei 430223, China
  • Received:2019-01-03 Revised:2019-03-26 Online:2019-06-28 Published:2019-04-26

Abstract: In the drilling and completion process of a shale oil exploration well,it is necessary to evaluate the oil-bearing property and movability of shale oil in time.However,the existing well-site evaluation techniques are developed primarily for conventional sandstone reservoirs,thus cannot meet the requirements of shale heterogeneity description.Therefore,it is in urgent need to establish a specific experimental procedure for shale oil drilling.In accordance with the requirements of rapid well-site geological evaluation and the technical limitations of available instrumentations,we proposed item selection,sampling,sample preservation and technical workflow for on-site experiment.Furthermore,this workflow was tested and applied in several well-site operations.A magnetohydrodynamic variable density rock bulk volume testing device was developed to solve the problem that it is hard to rapidly measure physical properties due to the difficulty to sample plungers for shales prone to loose and deform.In addition,a technique was invented to analyze the physical properties of shales with no fixed geometry.In order to minimize the evaporative loss of light hydrocarbons and to make Rock-Eval pyrolysis analysis data more reliable,shale samples were ground in liquid nitrogen freezing instruments.Analytical programs for well-site and lab tests were optimized and synergized to ensure more efficient workflow.These new methods were applied successfully to the Qianjiang Formation in Jianghan Basin,Shahejie Formation in Jiyang Depression and Chang 7 in Ordos Basin,laying a sound foundation for fast geological evaluation of continental shale oil exploration.Meanwhile,what should be pointed out is that the current well-site experimental technology is still far from perfect for China's shale oil exploration,for instance,a lack of related specifications and criteria.What we should do further is to improve the existing well-site experimental and applied technologies,develop normative methodology and technology systems,and build a rapid geological evaluation platform for shale oil exploration.

Key words: Rock-Eval pyrolysis, experimental workflow, testing technique, well-site experiment, rapid geological evaluation, shale oil

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