The fracturing job was one of the effective way to improve hydrocarbon reservoir' s permeability and raise oil and gas well' s production. In the fracturing operation, the formation and fracturing fluid temperature were coming linear or non-linear changes with the well depth. The fracturing fluid pressure was also coming non-linear changes with the well depth. The flow fracturing fluid, the static fluid outside the tubular and the fracturing string was selected as objects. The coupling analysis model of the physical field with the temperature field, flow field and stress field was set up. The 1 000 m model result of the fracturing string was obtained by adopting ANSYS software.The wellhead temperature about the fracturing string and fluid was 20 ℃. The inner wall temperature was 36.99 ℃. Its outer wall temperature was 50.55 ℃. The fracturing string temperature was 35.47 ℃ in the bottom of the well. The string model with 1 000 m was also selected as research objects. The result in the multi-physic and stress field is obtained. The fractional error in the well of head and bottom is respective 3.73％ and 5.97％. Wherefore,it has little impact by using stress field to evaluate the casing strength. Bur it has a certain impact on the axial stress and the hoop stress.%压裂作业是改进油气层渗透率、提高油气井产量的有效途径之一.压裂管柱在压裂施工中,地层温度及压裂液温度随井深发生线性或非线性变化,压裂液压力也随井深发生非线性变化.本文选取管内流动的压裂液、管外环空静止井液和压裂管柱为研究对象,建立了温度场、流场和应力场耦合分析的多物理场模型.利用ANSYS软件,计算得到1 000 m压裂管柱以及压裂液在井口处的温度均为20℃,管柱内外壁在井底处的温度分别为36.99℃、50.55℃,压裂液在井底处温度达到35.47℃.仍选取1 000 m压裂管柱模型,计算得出管柱在多物理场和应力场中,井口和井底处的等效应力相对误差分别为3.73%、5.97%.可见,采用应力场对压裂管柱强度评价影响不大,但对管柱的轴向应力、环向应力有一定的影响.
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