Research On Optimization Design Of Casing String Under Complex Conditions

In the exploration and development of deep well, much accident. in drilling. Due towell structure is complex, the casing multi-level, downhole working condition has moreuncertainty, casing failure accidents have occurred from time to time, difficult and greateconomic losses to the production of the gas well. Based on the analysis of ultra deep wellcasing failure forms and mechanism, research on casing design should consider theinfluence factors, to improve the design and evaluation of deep well casing.Through the research of three axis strength of casing string design method, accordingto the collapse strength of casing, and then through the tensile and compressive strengthwithin to check the strength of casing, the casing is selected to meet the requirements of the.If the tensile or compressive strength within does not meet the safety requirements, it needsto choose the casing strength design.In the optimization design using three axis should be special design strength of casingstring in the process of design and development of casing drilling environment, designresults meet the casing actual stress, meet the demand of oil and gas wells casing strength.Special design is generally in the conventional design is completed, the local design in aspecial section of the well, and then return to the whole wellbore strength check, in order toobtain the most reasonable design results.