Research On The Casing Repair Technology And Application In The Lengjia Oilfield

With the continuous extension of time,continuous adjustment of oilfield development plan,continue to implement various measures,resulting in casing working environment is becoming increasingly serious,casing damage will inevitably produce a variety of casing damage of oil and water wells,which can not be normal production,resulting in heavy losses of aspects to oil field.Casing damage in a variety of forms,but the main deformation,leakage,necking,fracture.The problem of casing damage of oil and water wells is a complex problem,which relates to the geological mechanics,fluid mechanics,material mechanics and other disciplines.Liaohe Oilfield cold home block is nineteen seventies found,deep heavy oil,80 years of'proven the extra-heavy oil conglomerate oil.The geological condition is very complex,with the oil well production time prolonged,the damage degree of Lengjia oilfield downhole casing.Because the oil exploitation is the main form of steam stimulation and steam flooding,and thermal recovery wells casing than ordinary oil well under more stress complex,its uniqueness lies in high temperature problems caused by steam injection.Steam injection so that the casing thermal stress,residual steam cycle may also generate cyclic stress,resulting in casing damage.According to statistics the cold block casing failure has 175,accounting for 12.56%of the total number of wells.Through the statistics of oil well casing in the packer to reservoir near the damage of casing damage wells accounted for total number 64.42%,damaged form accounted for 46.42%of the total wells casing,dislocation accounted for 23.31%of the total wells,casing thread joints leakage and tripping accounted for 16.35%of the total wells casing damage of casing deformation.Loss of Lengjia oilfield set becomes more and more serious,the operation and maintenance workload increased substantially,make oil invested large amounts of funds to control casing,the casing damage of oil and water wells become more and more serious phenomenon,serious damage to the injection-production balance,restricts the further adjustment of injection-production structure.Lengjia oilfield casing damage is mainly bending,shrinkage,breaking three forms,so the mechanism analysis and research situation domestic and coat loss,Lengjia oilfield casing damage were analyzed,to find out the influencing factors.Put forward the "prevention first,combining prevention with control" policy and "governance of casing damage wells must be preferred economic,effective,reasonable well repairing scheme,optimization of portfoliomanagement process to ensure that,in order to achieve the best economic benefit of" scheme,summarizes the main measures of Lengjia oilfield in the prevention and treatment of casing damage wells of in recent years,put forward valuable suggestions for the future development of Lengjia oilfield with high efficiency,worthy of other oil reference.