气井油管气渗引起的环空带压值预测模型研究

发布时间：2018-03-03 00:00

本文选题：气井　切入点：非API扣型　出处：《东北石油大学》2017年硕士论文　论文类型：学位论文

【摘要】：本文针对气井油管气渗现象,重点关注气井所使用的非API扣型油管的气渗特性,并明确了公扣密封接触面及扭矩台肩侧向密封面的所形成的微小泄漏通道是气体逃逸的潜在通道。通过将粗糙表面数值化,并首先在不同工况下对非API扣型油管接箍进行总体有限元数值模拟,确定公扣密封接触面和扭矩台肩侧向密封接触面的接触面积及密封面处的接触应力大小;根据接触面积及接触应力值进行局部有限元求解,并基于局部有限元求解结果将最大法向应力处自仿射放大,重复局部有限元求解过程,直至得到泄漏通道连通时的放大倍数,并基于渝渗理论建立了泄漏率预测计算方法。根据气井的实际工况,基于临界放大倍数对泄漏率进行求解。本文对油管泄漏率的研究主要是基于采气区块大量发生的环空带压现象,因此其最根本的研究目的便是环空带压诊断。基于气井采气管柱气渗泄漏率计算模型,建立了气渗引起的环空带压值预测模型。同时考虑到泄漏率本身处于动态变化,因此对泄漏率计算模型进行了修正,并提出了基于不同时间间隔的动态环空带压模型,进而为环空带压诊断提供了理论依据。同时基于室内气密封能力测试及实际采气井验证了所建立模型的正确性。
[Abstract]:In this paper, the gas permeability characteristics of non-#en0# tubing used in gas wells are focused on the gas permeability phenomenon of gas well tubing. The tiny leakage channel formed by the contact surface of the common buckle seal and the lateral seal surface of the torque table shoulder is a potential channel for gas escape. At first, the general finite element numerical simulation of non-#en0# tubing coupling is carried out under different working conditions to determine the contact area and the contact stress of the contact surface between the common buckle seal surface and the torque table shoulder lateral seal surface. According to the contact area and contact stress value, the local finite element method is used to solve the problem. Based on the local finite element solution results, the maximum normal stress is amplified by self-affine amplification, and the local finite element solution process is repeated until the amplification multiple of the leakage channel is obtained. Based on the theory of Yu-permeability, the calculation method of leakage rate is established. According to the actual condition of gas well, In this paper, the leakage rate of tubing is mainly based on the phenomenon of annular zone pressure occurring in gas production blocks. Therefore, the most fundamental purpose of its research is to diagnose the annular zone pressure. Based on the calculation model of gas-permeability leakage rate of gas well gas production string, the prediction model of annular zone pressure caused by gas permeability is established. At the same time, considering the dynamic change of leakage rate itself, Therefore, the leakage rate calculation model is modified, and the dynamic annulus band pressure model based on different time intervals is proposed. It also provides a theoretical basis for the diagnosis of annular zone pressure, and validates the correctness of the model based on the test of indoor gas seal ability and the actual gas production well.
【学位授予单位】：东北石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TE38

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