The Technology Of Repairing Wells That Have Damaged Oil String In Daqing Oil Field By Sidetracking Uncased Hole

According to the difficulties in repairing wells that have damaged oil string in daqing oil field by the technology of sidetracking uncased hole,the technology of getting oil string in low reservoir,the well profile design,the technology of avoiding touching,the relationship between rock and bite,calculated software, the technology of well cementation are studied. The depth of getting oil string which was 250～450m is made out in the technology of getting oil string in low reservoir research.The type of the well bore profile which is angle build-hold angle-decreasing hole angle is designed. Parameter of well segment is calculated by using maximize hole angle mean. The contrail of well is calculated by using curvity radius mean.The mechanism of the wall of well's stability in sidetrack drilling is sdudied,the liquid used in repairing wells is choosed. So the difficulties of the wall of well's stability in sidetrack drilling was resolved. And the constuction work is carried out successfully. Some software are developed ,such as the well profile design software,the calculating contrail of the well software,the describing interrelativity of each well software. The technology of well cementation suited to the sonstruction work for sidetracking well is developed.The percent of the coincidence rate is 99.36%, the percent of the high grade rate is 74.36%.This technology is applied on lacation successfully,422 wells was constructed in 2002~2004,the successful ratio is 98%,the ratio of wells that have heavy repair is improved from 72.8% to 84.6%. The number of wells sidetracked increased year by year,the cycle time becomes more and more shorter,the proficiency degree of the technology becomes more and more advanced.The application of the technology brings economic benefit and society benefit.