Casing Cement Sheath Stress Analysis Based Control Theory

Currently, according to the actual oil field oil field development project status andrequirements, this paper analyzes the cement ring injuries necessity of research aredescribed. Meanwhile, the proposed approach based on control theory to explain theinjection pressure, stress, casing cement the relationship between the force and controltheory is applied to water stress formation and casing cement the force analysis, cementingbasic theory and cement casing damage study provides a new method. In this paper, basedon the FSI control theory with the method of transfer function analysis of water under highpressure casing-cement-the formation of the force as a research and taken first on theanalysis of the mechanical properties of cement, including cement carrying capacity anddeformation capacity, since cement is the most powerful protection sleeve most immediatebarrier, thus establishing different load cases casing-cement carrying capacity,anti-collapse strength related mechanical model, and analyzed, drawn cement ring radialstress and tangential stress and pressure inside the casing and formation pressurerelationships, and the elastic modulus of the cement sheath on casing pressure test theeffects of these formations are determined to provide a reference injection pressure. Andaccording to cementing ring suffer from a double casing and formation pressure, analyzescement sheath destruction limit. Finally the introduction of the transfer function method, thevarious forces will be more intuitive to use simplified control functions expressed, directlyor indirectly, to control the formation of relationships and the use of inverse Laplacetransform by a change back to the original function as a function, and use the obtainedfunctions performed data analysis, which is based on control theory paper cementmechanics research methods. Thesis has been made on the basis of information, combinedwith the finite element ANSYS software functionality, numerical simulation, the simulationresults and data transfer function method were compared and found very close. The resultsnot only in the theoretical study has to reference, but also to improve oil production, qualityassurance wells also have some guidance.