Geological Evaluation And Countermeasure Of The Salt Cavern Of Underground Gas Storage In China

Salt deposits in China is characterized by thin bedded salt layer with thick insoluable interbeds,while in the United States and Europe thick salt layers with rare insolubale interbeds are dominated.The Geological condition of construct the salt cavern gas storage in China is worse than abroad.This thesis aims to analyse the construction of the West-East Jintan gas storage.Based on the exploration,collecting and analyzing data,field geological mapping,core observation,and the interpretation of the logging data,we study the structural geology and the salt deposits sedimentology of the research area.We propose the salt cavern gas storage site selection and evaluation methods,and solutions in the evaluation of the China-style bedded salt deposit.Finally,we analyse two salt mines,P and Y,using the methods proposed by the thesis.1.On the status of development of global gas storage salt cavern,geological characteristics of the salt basins,we found that the salt cavern gas storage can be divided into the salt dome and the bedded salt deposit style.The type of gas storage in salt domes North America,Europe,is represented by the huge salt thickness,high-grade rock salt and less interbeded layer,while the bedded salt layer is typical in our country,with moderate thick salt,medium-grade salt,and high water-insoluble impurities.The complex geological conditions in China is challenging for the geological evaluation.2.Based on the 3D seismic interpretation,we analyse the core sample,well loggings,the solution testing of the salt,and the integrity test of the capping rock and the interbedded rock.The structural and the sedimentary framework of the Jintan area is understood.3.By analysising of the Jintan experience,we designed the geological evaluation criteria for the China-style bedded salt deposit to construct the salt cavern storage by rating the candidate target using multiple indexes.4.For the disadvantages mentioned above in the China-style bedded salt layer,we carry out the techniques of interbed integrity test method,evaluation of the content of the insobules,and the pressure optimization in the opration,to evaluate the thin bedded salt and thick interbeds case in China.5.Two candidate target of the salt cavern storage,P and Y,are analyzed in this paper,using the hundred points scores rating method proposed by the thesis.The P salt mine scores 87 points,and the Y salt mine scores 80 points.The disadvantages and the proposed solution is mentioned in the paper.