川东北地区高压气井溢流机理研究

发布时间：2018-02-25 20:07

本文关键词： 川东北裂缝性储层溢流机理高压气井井控　出处：《西南石油大学》2015年硕士论文　论文类型：学位论文

【摘要】：能源消费结构调整加速天然气资源的勘探与开发,川东北地区作为四川天然气资源重点探区之一,也是“川气东送”工程资源接替的重要阵地,加快川东北地区天然气资源的勘探与开发意义重大。由于川东北地区陆相高压裂缝性储层地质条件复杂,钻井过程中常常钻遇储层裂缝,容易导致突发性溢流,出现溢流情况后井控难度大,可能造成巨大的经济损失和人员伤亡。因此迫切需要对该地区溢流机理展开深入研究。本文在充分调研国内外多相流理论研究与井控理论研究进展的基础上,结合川东北地区陆相高压裂缝性储层特点,对溢流的侵入、发生、发展及地面控制等过程展开系统的理论与实验研究,主要开展了以下几部分研究工作： (1)广泛调研和总结了多相流理论研究、井控理论研究及裂缝性储层气侵溢流研究的进展。在此基础上,深入分析了川东北地区高压气井钻井过程中容易遭遇突发性溢流、处理难度大等特殊井控问题,据此提出了本文的研究方向及思路。 (2)开展了川东北地区地质特征分析。从川东北地区地质构造、储层条件和岩心特征等方面分析了川东北地区陆相高压裂缝性储层面临的复杂地质条件,发现该地区主要溢流层段为自流井组和须家河组,井深为4500-5500m,且表现为溢漏同存,钻井现场典型溢流井特征为后续井筒溢流侵入模型与压力分布规律模型的建立提供了基础地质参数与工程参数。 (3)建立了井筒溢流动态侵入模型。在分析川东北地区陆相高压裂缝性储层溢流条件和溢漏规律的基础上,利用气体渗流理论建立了溢流发生时的侵入量计算模型,并利用川东北地区典型溢流井进行了实例计算,揭示了溢流的侵入及发生机理。 (4)开展了井筒压力分布规律研究。根据前述建立的溢流侵入量计算模型,基于漂移流模型和气液两相流理论,建立了溢流井筒气液两相流数学模型,并借助计算机编程,采用有限差分法求解该模型,认识地层气体侵入井筒后从重力置换溢流向欠平衡溢流转换并不断发展变化的过程。 (5)开展了井筒气体运移规律实验与仿真研究。根据相似理论设计并搭建了气侵溢流实验系统台架,真实观测气体侵入井筒后的运移规律及井底压力变化情况,发现井筒流型变化主要受初始气侵速度的影响,井底压力在气体侵入瞬间激增；同时进行了数值模拟对比验证,实验与仿真结果吻合。 (6)开展了川东北地区陆相高压裂缝性储层压井工艺研究。通过前述对溢流发生及发展后井筒特征变化的认识,分析了正循环法、反循环法和置换法等常规堵漏压井工艺技术,并结合川东北地区陆相高压裂缝性储层溢漏特点和压井工艺影响因素展开了堵漏压井方法适应性评价,建立了适合川东北地区陆相高压裂缝性储层的堵漏压井方法选择流程。综上所述,本文的研究工作为川东北地区陆相储层钻井现场溢流认识与压井施工的科学选择提供了可靠依据,并对实现我国四川盆地川东北地区天然气资源的安全、平稳、高效开发产生重要意义。
[Abstract]:The energy consumption structure regulates the exploration and development of natural gas resources . The northeast area of Sichuan is one of the key exploration areas of Sichuan natural gas resources . It is also an important position for the replacement of gas resources in the northeast of Sichuan , and it is very important to accelerate the exploration and development of natural gas resources in Northeast Sichuan . Based on the research of the theory of multiphase flow theory and well control theory at home and abroad , the theory and experimental study of the system of invasion , occurrence , development and ground control of overflow are studied in this paper . ( 1 ) The research of multiphase flow theory , well control theory and the research of gas invasion and overflow of fractured reservoir are researched and summarized . On the basis of this , the problems of sudden overflow and difficulty in the well control of high pressure gas wells in Northeast Sichuan are analyzed in depth , and the research direction and thinking of this paper are put forward . ( 2 ) The analysis of the geological characteristics of the Northeast China is carried out . The complex geological conditions faced by the continental high - pressure fractured reservoirs in the northeast of Sichuan were analyzed from the aspects of geological structure , reservoir condition and core characteristics . It was found that the main overflow layer in the region was artesian well group and Xujia river group . The well depth was 4500 - 500m , and the typical overflow well in the drilling site provided the basic geological parameters and engineering parameters for the establishment of the model of overflow invasion and pressure distribution of the subsequent wellbore . ( 3 ) The dynamic intrusion model of well bore is established . Based on the analysis of overflow condition and overflow rule of continental high - pressure fracture reservoir in northeast China , the intrusion amount calculation model is established by using gas percolation theory , and the example calculation is carried out by using typical overflow wells in northeast of Sichuan , and the invasion and mechanism of overflow are revealed . ( 4 ) The distribution law of wellbore pressure is studied . According to the above - mentioned model of overflow calculation , the mathematical model of gas - liquid two - phase flow in overflow wellbore is established based on drift - flow model and gas - liquid two - phase flow theory , and the model is solved by means of finite difference method . ( 5 ) The experiment and simulation of gas migration in wellbore were carried out . According to the similarity theory , the experiment system of gas invasion and overflow was designed and constructed . The results show that the change of wellbore flow pattern is mainly affected by the initial gas invasion velocity , and the pressure of the well bottom is increased at the moment of gas invasion . Meanwhile , the numerical simulation comparison is carried out , and the experiment is consistent with the simulation results . ( 6 ) The research on the pressure well process of the continental high - pressure fracture reservoir in the northeast of Sichuan province is carried out . Through the above - mentioned understanding of the characteristics change of the well bore after the overflow and the development , the normal circulation method , the reverse circulation method and the displacement method are analyzed , and the adaptive evaluation of the plugging pressure well method is carried out according to the overflow characteristics of the continental high - pressure fracture reservoir in the northeast of Sichuan and the influence factors of the pressure well process , and the selection flow of the plugging - plugging and kill - well method suitable for the continental high - pressure fracture reservoir in the northeast of Sichuan is established . In conclusion , the research work of this paper provides a reliable basis for the field overflow recognition and the scientific choice of pressure well construction in the continental reservoir drilling in the northeast of Sichuan , and it is safe and stable to realize the natural gas resources in the northeast area of Sichuan Basin , China . high - efficiency development is of great significance .

【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】：TE28

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