基于温度压力影响的井底压力计算方法研究

发布时间：2018-11-22 07:25

【摘要】：随着人们对油气资源需求量的逐渐增多,勘探开发目标已向深部地层快速发展,深井／超深井钻井数量逐年飙升。然而,在深井／超深井钻井过程中井下复杂事故多发频发,尤其在深部地层中经常出现钻井液性能失控、井漏、漏喷同层和气侵等情况。据有关研究表明,井底压力计算或预测不准确是导致上述井下复杂事故的主要原因。为此,本文基于井筒温度场和压力场,以考虑温度压力影响的钻井液流变性和密度实验为基础,推导出了考虑温度压力影响的井底压力计算模型。本文主要开展了以下研究工作： (1)根据热力学定理和能量守恒原理,推导出了钻井液循环期间钻柱内和环空温度场模型,并编写了相关计算程序。结合川西地区某区块A井钻井施工参数,计算得出了钻柱内和环空钻井液温度随井深的分布规律。 (2)针对聚磺水基钻井液体系开展了考虑温度压力影响的钻井液流变性实验,采用回归分析法得出该钻井液体系符合赫-巴流变模式。应用多元非线性回归方法得出了温度压力影响下的钻井液流变参数模型,为环空循环压耗准确计算提供了理论基础。 (3)根据赫-巴流体同心环空层流波动压力理论,建立了赫-巴流体同心环空层流循环压耗新模型,并编写了相关计算程序。通过实例计算,得到了考虑温度压力影响的环空循环压降是随井深增加而减小的动态变化规律。 (4)基于环空循环压耗新模型,对钻井液流变性、泵排量、环空内外径比率和钻进速度进行了环空循环压耗单因素影响分析,结果显示钻井液流变性、泵排量和环空内外径比率会对循环压耗产生明显影响,而钻进速度对循环压耗几乎无影响。 (5)根据温度压力影响下的钻井液密度实验结果,采用多元非线性回归方法得出了温度压力影响下的钻井液密度预测新模型。结合研究成果,采用C语言编写了考虑温度压力影响的井底压力计算机程序。通过本文的研究,形成了一套考虑温度压力影响的深井／超深井井底压力计算方法,为安全、快速、高效和经济钻井创造了条件,这对深部油气资源勘探开发具有重要的指导意义和现实意义。
[Abstract]:With the increasing demand for oil and gas resources, the target of exploration and development has developed rapidly into deep formation, and the drilling quantity of deep well / ultra deep well has soared year by year. However, during deep / ultra-deep well drilling, complex downhole accidents occur frequently, especially in deep formation where the drilling fluid performance is out of control, well leakage, leakage layer and gas invasion occur. According to relevant studies, the inaccuracy of bottom hole pressure calculation or prediction is the main cause of these complex downhole accidents. Therefore, based on the wellbore temperature field and pressure field, based on the rheological and density experiments of drilling fluid considering the influence of temperature and pressure, a calculation model of bottom hole pressure considering the influence of temperature and pressure is derived. The main work of this paper is as follows: (1) according to the thermodynamic theorem and the principle of energy conservation, the temperature field model of drilling string and annulus during drilling fluid cycle is derived, and the relevant calculation program is compiled. Based on the drilling parameters of well A in a certain block in western Sichuan, the distribution of drilling fluid temperature with well depth in drill string and annulus is calculated. (2) experiments on rheological properties of polysulfonated water-based drilling fluid system were carried out considering the effect of temperature and pressure. Regression analysis method was used to obtain that the drilling fluid system was in accordance with Herba rheological model. The rheological parameter model of drilling fluid under the influence of temperature and pressure is obtained by using multivariate nonlinear regression method, which provides a theoretical basis for accurate calculation of circulation pressure consumption in annulus. (3) based on the theory of wave pressure in the concentric annulus of Herba fluid, a new pressure consumption model of the annular laminar flow in the concentric annulus of Herba fluid is established, and a related calculation program is compiled. Through practical calculation, the cyclic pressure drop considering the influence of temperature and pressure is found to be a dynamic variation law that decreases with the increase of well depth. (4) based on the new annular circulation pressure consumption model, the single factor influence analysis of drilling fluid rheology, pump displacement, annulus internal diameter ratio and drilling speed is carried out. The results show that the rheology of drilling fluid is different. The pump displacement and the ratio of inner and outer diameter of the annulus have obvious influence on the circulating pressure consumption, while the drilling speed has little effect on the circulation pressure consumption. (5) according to the experimental results of drilling fluid density under the influence of temperature and pressure, a new model of drilling fluid density prediction under the influence of temperature and pressure is obtained by using multivariate nonlinear regression method. Combined with the research results, the computer program of bottom hole pressure considering the influence of temperature and pressure is compiled by C language. Through the research in this paper, a set of deep / ultra-deep well bottom pressure calculation method considering the influence of temperature and pressure is developed, which creates conditions for safe, fast, efficient and economical drilling. This is of great significance to the exploration and development of deep oil and gas resources.
【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE21

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