Reservoir Contaminated Zone Identification And Evaluation Using Well Logs

The problem of reservoir harm will exist in all process of field prospecting and development,which declines reservoir deliverability and causes economic loss,so hydrocarbon reservoir’s protection work is more and more valued.The form and reason of reservoir harm is complex and changeable.There have a big difference of damage in different fields,and even different well in the same blocks.In the development of oil field,for more economic benefits,there should make strict and effective reservoir protection measures and remedy,study the reservoir damage problem,provide the guiding ideology on the theory and practice for the implementation of the subsequent drilling.On the base of abundant of conventional log data and half well logging data and well test data,analyzed mud invasion mechanism,established reservoir sensitivity anticipation pattern and evaluated reservoir degree of damage in the use of drill fluid invasion depth,permeability damage ratio,skin factor.On the base of abundant of log data、well logging data、well test data and core analysis,this paper has analyzed in reservoir sensitivity and established reservoir sensitivity evaluation pattern,and predicted the real well,achieved good evaluation results.Then on the base of text data,refer to conventional log approach and rule,by means of log response alternation caused by mud filtrate invasion,summed up log response feature of reservoir harm,in the way of regression analysis and neural net mathematical methods,has established log qualitative assessment and quantitative assessment of oil/gas reservoir extent of damage in the use of drill fluid invasion depth,permeability damage ratio,skin factor.Using conventional logging data to evaluate oil/gas reservoir extent of damage will reduce reservoir test cost.It will have an important significance in development of the field with economic benefit as the center.