注蒸汽井温度场分布和套管热应力分析

【作者】 冯少波；

【导师】 李黔；

【作者基本信息】 西南石油学院 ， 油气井工程， 2002， 硕士

【摘要】 稠油热采技术早在20世纪初就开始了工业性试验、随后稠油热采技术得到了很大的发展。稠油热采主要形式是蒸汽吞吐和蒸汽驱，但是蒸汽的注入使得套管产生热应力，套管损坏非常严重，很大程度上制约着注蒸汽开采稠油技术。 本文应用热传递基本理论，通过井筒内能量守恒、动量守恒和质量守恒定理建立了注蒸汽井注入阶段井筒-地层温度场模型，同时建立焖井阶段的套管温度变化模型。在注入阶段井筒热传递的计算中，引入了时间步函数，使得结果更符合实际情况。 在得到井筒-地层温度场模型后，应用热应力基本理论建立了套管热应力计算模型。同时编制了计算软件对现场注蒸汽的实际情况进行模拟，研究了套管温度和热应力的分布规律，并且计算结果与现场实测值非常接近，这说明了本模型客观地反映了注蒸汽的真实情况。本模型可用于现场注蒸汽井动态预测和模拟，以及对蒸汽注入参数进行优选，同时可对套管热应力进行计算分析。 在文章的最后部分，建立了提拉过程中套管在井筒中受力平衡的关系式，推导出提拉过程中提拉预应力的分布模型。该模型在前人研究的基础上考虑了摩阻力对井口提拉载荷的影响。并得出了采用提拉预应力固井方法后注蒸汽所产生的热应力分布规律。更多还原

【Abstract】 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.更多还原