Cause analysis and preventive measures of casing failure in Wenmi Oilfield

Through decades of development, the number of casing failure wells in Wenmi Oilfield has increased year by year, due to the interaction of various factors. According to the statistics of the casing failure wells over the years, the number of casing failure wells increases, as the water injection pressure and the formation pressure increase. In this paper, five factors are analyzed, i.e., the block where casing failure occurs, the time when casing failure occurs, the well patters of casing failure, the deformation properties of casing failure, and the downhole operation. Analysis shows that the major causes of the casing failure in the oilfield include the downhole operation including perforation and acid fracturing, the waterflooding and the faults exist in the oilfield. The minor causes include the corrosion, the gas injection, and the quality of steels. Measures for preventing casing failure are also proposed, offering a reference for the control of casing failure in oilfields.