Steam Injection Well Temperature Distribution And Casing For Thermal Stress Analysis

The industrial tests of the technique of exploiting heavy oil start at early the 20th century, after that the technique of exploiting heavy oil have rapid development. The exploit of heavy oil mainly through steam huff and puff and steam drive. But the casing will produce large heat stress for the injection of steam, and can make heavy casing failure. Therefore in large degree restrict the development of steam injection technique.Applying the basic theory of heat transfer, this paper have established the well bore and formation temperature field model of steam injection step, and have established the casing temperature change model of the steam soak step. In the calculation of well bore heat transfer of the steam injection step, this paper introduce the time step function and make the result accord with the fact much more.After getting well bore and formation temperature field model, this paper using the basic theory of heat stress establish the model of casing heat stress. At the same time the calculating software can simulate the fact of steam injection, and this paper have researched the rule of casing temperature and heat stress. The results of calculating are very close to the measured value, and this can prove that this model accord with the fact of steam injection. This model can use to predict and simulate the steam injection, and prefer the steam inject parameter, furthermore this model can calculate and analysis the heat stress of casing.In the end of this paper, the relationship of casing under force balance in the process of drawing casing is established, and the prestressing force distribute model is deducted. This model haveconsidered the effect of friction to well head drawing force, especially curved portion must take friction into account. And then this model can get the heat stress distribute rule induced by steam injection after drawing casing.