Response characteristics of gas hydrate well-logging in Muli area
LIN Zhen-Zhou1, 2, LIU Dong-Ming2, PAN He-Ping1, LI Yang2, GAO Wen-Li2, QIU Li-Quan2, ZHANG Xiao-Wei3
1.Institute of Geophysics and Geomatics,China University of Geosciences (Wuhan),Wuhan 430074,China; 2.Institute of Geophysical and Geochemical Exploration,CAGS,Langfang 065000,China; 3.Dongfang College,Beijing University of Chinese Medicine,Langfang 065000,China
Abstract:The presence of gas hydrate and the lithology of reservoirs in Muli area are significantly different from those in the sea area or polar permafrost zone.For analyzing the logging response characteristics of the hydrate reservoir in the study area,the hydrate storage layer identification method is of great significance for hydrate exploration in this area.In this paper,the characteristics of well logging and the causes of hydrate logging were discussed by using conventional logging and ultrasonic imaging logging data, and the characteristics of reservoir logging parameters were calculated.The hydrate recognition was carried out in the study area.Some conclusions have been reached:(1) The apparent resistivity and natural gamma ray are sensitive to the pore hydrate, and the apparent resistivity and the longitudinal wave velocity are sensitive to the fissure hydrate.(2) The thick hydrate of the geological catalog could be identified,with the identification of some suspected hydrate reservoirs,but a small amount of drilling thin layer of hydrate failed to identify the analysis of the reasons for the low hydrate content,resulting in non-obvious logging response characteristics;(3)10 wells in the study identified hydrate and suspected hydrate anomalies,in which the cumulative thickness of the pore-type reservoir was 89m,and the cumulative thickness of the fractured reservoir was 151.6m.Therefore, the fractured hydrate reservoir is the main research area.In summary,the geophysical logging method has a good response to the hydrate reservoir,and can be effectively applied to the reservoir identification of all the boreholes in the study area.
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