A SUMMARIZATION OF PROGRESS IN EXPERIMENT AND STUDY OF RESERVOIR DAMAGE CAUSED BY DRILLING

The reservoir damage caused by the drilling of oil and gas wells will greatly reduce the productivity of oil and gas wells.The study of reservoir damage caused by drilling includes indoor experiment and reseach and site evaluation and reseach.The purpose of the indoor reseach is to understand the mechanism causing reservoir damage and,based on this,to take the suitable reservoir protection measures,such as taking a clear aim to select the drilling fluid favourable to reservoir protection and evaluating the drilling fluid.In this paper,the progress in study of reservoir damage (including the mechanism of reservoir damage,development of simulation device,study of protection technique and formulating the standard,etc.)is summarized and the actual situation of the experiment and research of reservoir damage caused by drilling and the existing problems are summed up and analyzed,obtaining several conclusions as follows:(1)In respect to the mechanism study of oil reservoir damage,the main mechanism of reservoir damage has been basically understood and the study has entered the stage “from qualitative study to quantitative one”;(2)The indoor simulation device is developing toward simulating high temperature and high pressure reservoir condition,dynamic contamination of rock sample,automatization and multifunction;(3)The standardization of the indoor evaluation method and simulation device is poor,which seriously affects the accuracy of the research results;(4)As compared to the degree of oil reservoir damage study,gas reservoir damage study is still in initial stage and all methods are qualitative,and there are no suitable evaluating device,methods and standard.