Method Of Fluid Identification For Complex Mud Invasion Reservoir

Focused on the research of Jurassic Yanan Formation of Ordos Basin,Fluid Identification about this Formation has researched.Then,a reservoir fluid identification is developed to identify reservoir fluid when the Complex Mud Invasion exists.Firstly,based on the logs,drilling,testing and other information of more than 200 wells,griping the necessary data,such as invasion days,formation water salinity,response characteristic and type.And challenges which complex mud invasion of reservoir brings to logging evaluation have been analyzed.Secondly,based on invasion theory and dynamic response of resistivity logging,a mud invasion simulation method has been build to simulate the fresh water mud invasion of different saturation,physical property and formation water salinity effect on formation resistivity profile changes.Complex invasion is clearly the main puzzle for log interpretation in Jurassic Yanan Formation.In summary,through combining the analysis results with the logs,the ‘three steps' method are proposed in this study to evaluate reservoir fluid properties.And applied to the actual data validation,the method basically solves this puzzle identification for oil and water of Jurassic Yanan Formation.