Research On Drilling Fluid Evaluation And Reservoir Protection Technology Improvement In Gulong Block

Since the end of 1980s we paid attention to reservoir protection.Though the basic causes of formation damage are known,given a reservoir,we must analyze the idiographic reasons of it due to the variety of geology and formation condition.In this paper,we have made systematically appraisal to Daqing Gulong area reservoir sensitivity and the extent of damage according to standard test procedure,the result is as following:Velocity sensitivity(medium),water sensitivity(weak medium),the damage of water-lock(strong),Other related damage(week).Based on sensitivity analysis,a systematic study on formation damage mechanism is carried out,which indicates that the main reason causing DaQing gulong area formation damage is the liquid phase damage,and the solid phase damage is very little.After generalized analysis the primary cause of damage reservoir by drilling fluid,we propose improvement program of the two drilling fluids(Amphoteric composite ion drilling fluid and Emulsion high polymer drilling fluid)which can control the formation damage,and then appraise formation damage control effect of the improvement drilling fluid.