注水泥流动摩阻的准确计算方法研究与现场应用

发布时间：2018-01-22 05:07

本文关键词： 固井质量温度小间隙摩阻系数计算方法　出处：《西南石油大学》2016年硕士论文　论文类型：学位论文

【摘要】：固井工程作为钻井工程中至关重要的一环,直接关系到油气井的产能和寿命,而注水泥又是整个固井工程中的重中之重。注水泥是一次性工程,也是我们看不到的隐蔽工程,一旦出现问题,不仅很难补救,造成的经济损失也是不可估量的。注水泥过程中,水泥浆流动摩阻受流态、环空间隙大小、温度以及局部阻力等因素的影响,以致其计算结果误差较大,当误差太大时,就会影响到注水泥固井的质量。因此,本文主要以提高水泥浆流动摩阻计算准确性为目的,对流变模式,流态判别方法,温度影响,局部阻力影响等几个方面进行研究；并编写了注水泥流动摩阻计算的软件。本文分析流态判别的方法,发现常用的雷诺数判别法对牛顿流体判别相对准确,对塑性和假塑性流体的判别有着较大的误差。而Z值判别法是基于分层雷诺数的判别方法来计算的,它能对每一层流体进行计算,即使存在偏心环空也可以应用。利用计算不同温度下的流变参数,提出了按循环温度分段的方法,建立了考虑不同温度下流变性的环空计算模型。分析环空尺寸的不同对流动摩阻计算的影响,发现环空尺寸的不同影响着临界流速、水泥浆流变性、摩阻系数等参数,提出了小间隙的流态判别标准及修正雷诺数的计算公式。论文考虑了套管接头产生局部阻力对注水泥流动摩阻的影响,发现当井越深的时候套管接头产生的局部阻力影响就会越大。从而建立了针对渐扩渐缩型和突扩突缩型两种套管接头产生局部阻力的计算模型。最后,论文根据建立的理论模型参与编写了注水泥流动摩阻计算的软件,对不同地区进行现场施工应用。通过多口井的数据计算其误差的大小,并确定本文计算方法的准确性。从而使固井注水泥设计更加的合理,施工更加安全。
[Abstract]:Cementing engineering, as an important part of drilling engineering, is directly related to the productivity and life of oil and gas wells, and cementing is the most important part of the whole cementing engineering. Cement injection is a one-off project. Once there is a problem, it is not only difficult to remedy, but also the economic loss is inestimable. In the process of cement injection, the flow resistance of cement slurry flow, the size of annulus clearance. Because of the influence of temperature and local resistance, the error of calculation result is big, when the error is too big, it will affect the cementing quality of cement injection. In order to improve the accuracy of flow friction calculation of cement slurry, the rheological model, flow pattern discrimination method, temperature effect and local resistance are studied in this paper. In this paper, the method of judging flow state is analyzed, and it is found that the commonly used discriminant method of Reynolds number is relatively accurate for the identification of Newtonian fluid. There is a great error in the identification of plastic and pseudoplastic fluids, and the Z value discriminant method is based on the discriminant method of stratified Reynolds number, which can be used to calculate every layer of fluid. Even if the eccentric annulus exists, it can be applied. By calculating the rheological parameters at different temperatures, the method of dividing the cycle temperature into sections is put forward. A calculation model of annulus considering rheology at different temperatures is established. The influence of annulus size on the calculation of flow friction is analyzed. It is found that different annulus size affects critical flow velocity and cement slurry rheology. Parameters such as friction coefficient, the criterion for judging flow state of small gap and the formula for calculating modified Reynolds number are put forward. The influence of local resistance produced by sleeve joint on flow friction of cement injection is considered in this paper. It is found that the local resistance of casing joint will increase when the well is deeper, and the calculation model of local resistance is established for the two types of casing joint: gradual expansion and sudden expansion and contraction. According to the established theoretical model, the paper compiled the software to calculate the frictional resistance of cement injection flow, and applied it to the field construction in different areas, and calculated the error through the data of many wells. The accuracy of the calculation method is determined so that the cementing cement design is more reasonable and the construction is more safe.
【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TE256

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