Research And Application Of Compound-Polyol Brine Drilling Fluid

The formation conditon in Daqing oilfield is complex,higher requirements of the drilling fluid.Amphoteric compound ion drilling fluid is often used in Daqing oil field.Survey within 2500 meters north of songliao basin of Daqing oil field at present in the shallow Wells,Wells,or the amphoteric compound ion development well use drilling fluids are shortcomings or defects,especially for drilling fluid system is weak,hole enlargement ratio is large,lead to irregular borehole,to produce a great impact on the well logging and well cementing;Strong water sensitivity and strong stress mud shale stability is always a difficult problem to drilling fluid technology,the oil-base drilling fluid in usual used to overcome,but the environmental protection in recent years more and more get the attention of people,application of oil-base drilling fluid tightly restricted.Since the late 90s started the research and development,therefore,polyol water-based drilling fluid.The system not only has the excellent properties of oil-based drilling fluid,and there exists no problem of environmental pollution and interference geological logging.According to the pressing needs of the market and development situation at home and abroad,after full argument,we identified combines organic salt and alcohol products supporting treatment agent and compound alcohol use and development research direction of the brine drilling fluid.Through lots of experiments and demonstration the synthetic compound alcohol products,successfully used with organic salt and compound polyol brine drilling fluid system is developed.Through the use of on the spot show that the system has played a organic salt system and alcohol products advantages and make up for the deficiencies of each other.Are analyzed in this paper the types and reasons of the borehole instability,partition piece of borehole instability is studied in chemical factors,on the basis of compound alcohol salt water system is studied,and the field application shows that compound polyol brine drilling fluid has strong inhibitory and reservoir protection effect.