Well Logging Assessment of Natural Gas Hydrate Reservoirs and Relevant Influential Factors
详细信息
- 责任者：Ning Fulong (Faculty of Engineering ; China University of Geosciences ; Wuhan 430074 ; China) ; Liu Li
- 刊名：Acta Petrolei Sinica
- 出版年：2013
- 卷期：34(3)
- 关键词：储集层 ; reservoirs ; 地球物理测井 ; geophysical logging
- 页码：p.591-606
- 图表：illus., 1 table, 94 refs.
- 分类号：1600
- issnNo：ISSN0253-2697
- isbnNo：CN11-2128/TE
摘要
The accurate identification and quantitative assessment of natural gas hydrate reservoirs are thought to be a base for development and utilization of gas hydrates and study of environmental impact.Besides seismic prospecting and core drilling,geophysical well logging is one of the most effective method of identification and evaluation to understand the nature of hydrate reservoirs.Resistivity and acoustic logging as the earliest applied geophysical methods in the identification of hydrate reservoirs are still ways for hydrate well logging due to their relatively good accuracy and reliability and therefore derive some new well logging methods such as ring resistivity,directional resistivity,multiple acoustic logging,etc.Other logging methods including borehole imaging,density,electromagnetic wave,nuclear magnetic resonance,etc.are also used together with resistivity and sonic logging to make an integrated interpretation and evaluation of hydrate reservoirs.With development of the past decades,well logging method of hydrate systems has finished a process from using single logging to adopting wireline and advanced logging-while-drilling tools to evaluate the petrophysical nature of gas hydrate reservoirs under complex geological conditions,and a preliminary theory and technology system based on conventional petrophysical models has been established.This system is generally suitable for homogeneous hydrate reservoirs,but not for heterogeneous argillaceous hydrate reservoirs(e.g.fracture,thin layer,interbed,shale-rich sediment,etc.).In addition,some external factors,such as wellbore washout and invasion of drilling fluid will also affect results of well logging.The present paper reviews the latest research progress in different well logging methods,and suggests that in the near future,new petrophysical models for identification and evaluation of complicated heterogeneous hydrate reservoirs as well as calibration methods for compensating defect caused by wellbore washout and invasion of drilling fluid in well logging will be set up or adopted to enhance accuracy of well logging in identification and evaluation of hydrate reservoirs.