Well logging evaluation of fine-grained hydrate-bearing sediment reservoirs: Considering the effect of clay content

作     者：Lin-Qi Zhu Jin Sun Xue-Qing Zhou Qing-Ping Li Qi Fan Song-Lin Wu Shi-Guo Wu 

作者机构：Laboratory of Marine Geophysics and Georesources of Hainan ProvinceInstitute of Deep-sea Science and EngineeringChinese Academy of SciencesSanya572000HainanChina Laboratory for Marine GeologyQingdao National Laboratory for Marine Science and TechnologyQingdao266061ShandongChina Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)ZhuhaiGuangdong519000China State Key Laboratory of Natural Gas HydratesBeijing100028China China National Offshore Oil Corporation Research Institute Co.Ltd.Beijing100028China 

出 版 物：《Petroleum Science》 (石油科学（英文版）)

年 卷 期：2023年第20卷第2期

页      面：879-892页

核心收录：

学科分类：0820[工学-石油与天然气工程] 08[工学] 082002[工学-油气田开发工程] 

基　　金：funded by the Laboratory for Marine Geology,Qingdao National Laboratory for Marine Science and Technology(No.MGQNLM-KF202004) Hainan Provincial Natural Science Foundation of China(Nos.422RC746 and 421QN281) the National Natural Science Foundation of China(No.42106213) the China Postdoctoral Science Foundation(Nos.2021M690161 and 2021T140691) the Postdoctorate Funded Project in Hainan Province 

主　　题：Gas hydrate Well logging Porosity Saturation Shale distribution form 

摘      要：Hydrate reservoirs are different from the host reservoirs of all other fossil energy sources because the characteristics of hydrate reservoirs are generally controlled by deep-sea fine-grained sedimentation. In such reservoirs, the reliability of the classical logging evaluation models established for diagenetic reservoirs is questionable. This study used well W8 in the Qiongdongnan Basin to explore the clay content, porosity, saturation, and hydrate-enriched layer identification of a logging-based hydrate reservoir, and it was found that considering the effect of the clay content on the log response is necessary in the logging evaluation of hydrate reservoirs. In the evaluation of clay content, a method based on the optimization inversion method can obtain a more reliable clay content than other methods. Fine-grained sediment reservoirs have a high clay content, and the effect of clay on log responses must be considered when calculating porosity. In addition, combining density logging and neutron porosity logging data can obtain the best porosity calculation results, and the porosity calculation method based on sonic logging predicted that the porosity of the studied reservoir was low. It was very effective to identify hydrate layers based on resistivity, but the clay distribution and pore structure will also affect the relationship between resistivity, porosity and saturation, and it was suggested that the factors effecting the resistivity of different layers should be considered in the saturation evaluation and that a suitable model should be selected. This study also considered the lack of clarity of the relationships among the lithology, physical properties, hydrate-bearing occurrence properties, and log response properties of hydrate reservoirs and the lack of specialized petrophysical models. This research can directly help to improve hydrate logging evaluation.