Study On Harmful Composition Analysis And Reduction Technology Of Drilling Fluid In Shengli Oilfield

With the exploration and development of Shengli Oilfield,the types and quantities of drilling fluid additives have increased rapidly.A variety of chemical treatment agents have increased the cost of subsequent environmental protection while ensuring the safety of underground wells.Due to the lack of qualitative and quantitative analysis methods for toxic and harmful components,the environmental risks caused by non-evaluation treatments have brought difficulties for the subsequent development of low-toxic,low-injury environmentally friendly drilling fluids.At the same time,there is no theoretical basis for the harmless treatment of abandoned drilling fluid,which is likely to cause adverse consequences such as environmental disputes and economic losses.With the country's emphasis on environmental protection and the increasingly stringent legislation and standards in relevant directions,it is necessary to carry out qualitative and quantitative analysis of the toxicity of drilling fluid additives,traceability monitoring of drilling fluids,Developing a new type of high-efficiency drilling fluid with low toxicity and low damage,and study the harmless treatment of drilling fluid waste.Firstly,the toxic and harmful components of common drilling fluid treatment agents were tested,and the environmentally friendly drilling fluid formula suitable for use in the Shengli oilfield was developed.At the same time,the high-efficiency flocculant for solid-liquid separation of drilling fluid was developed in response to the requirement of“sludge not falling”in Shengli Oilfield and the requirements of rapid reduction of drilling fluid waste.Through source control,process control,and end processing,environmental control is finally achieved throughout the drilling process.Through the research,it is found that the source of ensuring the environmental protection of the drilling fluid is the drilling fluid treatment agent.For the treatment agent with high environmental protection risk,the environmental performance test should be carried out before use,and the dosage should be strictly controlled during use,the environmental performance of the produced solid-liquid phase waste should be monitored at any time;The calcium chloride environmentally friendly drilling fluid system has good rheological properties at normal temperature and 120~°C,such as low fluid loss and good inhibition,The environmental performance test results meet the requirements of relevant national indicators,non-toxic,and low environmental damage.IT is Applicable to the depth of well below 3000 meters and below120~°C in Shengli Oilfield.The high-efficiency flocculant for solid-liquid separation of QA and JL-1 drilling fluid can accelerate the destabilization of waste and the flocculation and sedimentation of solid phase,so as to realize the rapid separation of solid and liquid phases.After treatment,the water content of cuttings can be controlled below 70%,meeting the transportation requirements,and the single well saves water by more than 40%.The calcium chloride drilling fluid system and the flocculation agent for solid-liquid separation of drilling fluids have good field test and application effect in many wells in Shengli Oilfield.The drilling system has been“reduced”and“not landed”,effectively promoting the environmental protection of drilling fluid while drilling,so that the harmful substances are treated in a closed loop,realizing the resource utilization of waste.