Mechanical Analysis And Optimization Design Of The Deeply Fracturing Packer

As oilfield be in the middle and later periods of exploitation, the oil layer’s watercapacity is rising, the contradiction between oil layers has been aggravated, the pressuredifference between water layer and oil layer is increasing; the oil Wells of new developmenthave been deepened, geological environment is becoming more and more poor. In the face ofcomplex the environment of oil Wells and the increasing demand of oil and gas, fracturingtechnology has been widely applied in oilfield’s production. But as a result of hightemperature and high pressure of the deep fracturing well, the problem of packer’s safeoperation and sealing reliability must be solved at present. Therefore, it is necessarymechanics analysis and structure optimization design of the packer to carry out.Considering material nonlinear, geometry nonlinear and double contact nonlinear of thecompressed packer rubber, the paper builds up the deformation equation of the multistagehardness and height rubber combination by the micro element method and the loadincremental method. The contact pressure and compressed length of the rubber are calculatedin each deformation step, and coMPared with the theoretical results and the results of finiteelement, their average error is less than5%. It provides a theoretical support for designing andmechanical analysis of the deeply fracturing packer.The paper analyzes the stress state of packer’s load-bearing component and calculatesstress of them and their dangerous cross-section with the material mechanics and the finiteelement method software, and evaluates their stress intensity on the basis of the classificationstandard in JB4732. The rubber’s three parameters (height, thickness, chamfering) isoptimized with software ANSYS, for getting its optimal structure size under different sealingpressure. It is more reasonable to use rubber structure of hard ends and soft middle than somestructures of reducing rubber shoulders "extrude". The simulated downhole experimentconfirmed the optimized packer sealing and bearing strength. It provides strong support fordesign and application of packer used in oilfield fracturing operation.