Mechanical Analysis And Strength Check Of Rod String During The Oil Test Operation

Oil and gas Wells rod string includes the drill string, casing, tubing and sucker rod string,etc. Mechanical analysis on the rod string can guide the construction, and reduce the oiltesting operation risk.For a start, this paper introduces the purposes, tools, and operating procedures in generalformation test, high oil and gas Wells with high temperature and high pressure formation test,conventional completion, acidizing fracturing, drilling bridge plug and gas lift as the basisfor string mechanics analysis. Next, the basic dynamics equations of the rod string in oil andgas wells was established, including the geometric equations, the equilibrium equation and theconstitutive equation. Then, it is established that the mathematical model of mechanicalanalysis about the column stability in inclined shaft and the differential equations of stringtension-torque analysis in directional well, with giving the continuous and boundaryconditions. And then, the mathematical model and the strength check method of differenttypes of tubing string tension-torque analysis are established respectively during the theprocess of down into, sealing, startup，testing，shut-in，backcycling, unsealing and lifting. Andit also established the theory of mechanics analysis and strength check on the gas oil teststring, fracture acidizing string, drainage pipe string and casing string.In the end, the above research results were used to analyze the basic data of seven wells.