H油田水平井分段注入压力及工艺研究

发布时间：2019-07-02 17:25

【摘要】：早期开发的H地区大型碳酸盐岩油田快速上产后还要求有较长时间的稳产期,目前衰竭式开发年自然递减率居高不下,衰竭式开发已经无法满足稳产的要求,水平注水井具有注入压力低和注入井段长等优点,能够有效补充地层的能量,驱替油层的原油,对提高油藏的采收率,保证油田的稳产和高产具有重要作用[1]。水平井的注水技术是崭新而且有潜力油田开发技术,油田开发过程中,水平井的注水技术具有非常大的优势,可增加注水量,提高波及体积和驱油效率,还可增加油藏的压力,改善油藏的开发效果。水平井的注水工程技术研究,是攻克大规模碳酸盐注水开发技术工程的技术保障。但是,段地层的非均质性较严重,沿水平井的井筒渗透率差异较大,高渗透的区域,渗流阻力小,而往往过早发生水淹;低渗透区域,具有渗流阻力大,注水较困难,油层的动用程度差,严重影响水平井的注水开发效果。要根本解决油层的连通性差、非均质的问题,则要分段注水。本文针对H油田注水储层深(Nahr Umr储层3600米、Mishrif储层3000米)、注入量较大(5000~10000stb)、层厚(平均厚度200~300米)、注水和采油井型井网较复杂(定向井注,水平井、定向井、及双分支井采)及水源匮乏的特点,为增加H油藏的开发效果,提高采收率,开展H注海配套工艺研究;针对长井段水平井在现场已经确定完井方式的条件下,本文开展水平井分段注水工艺研究。1.通过研究注入水与油藏和流体的配伍性,并依据石油天然气行业内标准,对H油田进行主要水源类型和水质指标的统计。并通过岩心流动实验总结不同的地层条件需要不同的水质标准。2.由于注海水与常规注水的注水水源水质的不同,分析总结了注海水要进行海水预处理的方法和项目。3.保护油水井套管关键因素是合理注水压力,本文分析发现管损和水嘴压力损失是注水压力损失主要因素。并通过合理注水压力公式分别计算了注入速率分别为8000bbl/d和6000bbl/d条件下,62mm,75.9mm,100.5mm三种规格的管柱合理注水压力。4.由于Mishrif碳酸盐岩油藏具有埋藏深、厚度大、非均质性强、单井注入量高、周围受影响油井多及井距、井型多样性的特点。所以,把示踪剂投放到注水井中,通过跟踪监测能够获得注入水在油藏中的存在、运动方向、渗流速度、平面及纵向联通对应关系及波及参数、孔道分布、评价水驱效果等地层物性和注水动态参数。通过综合对比分析与论证评价,初步推荐Mishrif油藏先导性实验井M279、M306及M325井首选示踪剂3种示踪剂。并通过示踪剂在淡水中的实验和在海水中的实验,可以发现推荐采用的三种无机盐类水溶化学示踪剂彼此兼容。5.根据水平井的注水特点,将水平井的注水,从井口到地层分为三段,依据各段流动特点,建立各段产量和压差之间关系模型,采用节点分析的原理,归纳出注入压力计算方法。依据理论公式:注水压力=注水井井底压力-液注产生的压力+总摩阻,编制了水平井分段注水注水压力计算的计算机模型。
[Abstract]:The early development of large-scale carbonate oil fields in the H area also requires a long period of stable and stable production, and the natural decline rate of the failure-type development has been high, and the failure-type development has been unable to meet the requirements of stable and stable production. The horizontal water injection well has the advantages of low injection pressure and long injection well section, can effectively supplement the energy of the formation and drive the crude oil of the oil layer, and has an important effect on improving the oil recovery of the oil reservoir and ensuring the stable and high yield of the oil field[1]. The water injection technology of horizontal well is brand-new and has the potential oil field development technology. In the process of oil field development, the water injection technology of horizontal well has a very large advantage, can increase the water injection quantity, improve the sweep volume and the oil displacement efficiency, and can also increase the pressure of the oil reservoir and improve the development effect of the oil reservoir. The research of water injection technology in horizontal well is a technical guarantee to overcome the development of large-scale carbonate water injection technology. However, the heterogeneity of the section formation is serious, the permeability of the wellbore along the horizontal well is large, the high-permeability region, the seepage resistance is small, and the flooding is often premature; the low-permeability region has the advantages of large seepage resistance, difficult water injection and poor utilization degree of the oil layer, And the water injection development effect of the horizontal well is seriously affected. In order to solve the problem of poor connectivity and heterogeneity of the oil layer at all, the water injection is to be segmented. In this paper, the characteristics of the depth of the water injection reservoir in the H field (the Nahr Umr reservoir,3600 m, Mishruf reservoir, 3000m), the injection volume (5000-10000stb), the layer thickness (average thickness of 200-300 m), the water injection and the well pattern of the oil well are more complex (directional well injection, horizontal well, directional well, and double-branch well production) and the water shortage. In order to increase the development effect of H-reservoir, to improve the recovery ratio and to carry out the research on the matching process of H-injection sea, the horizontal well section water-filling technology is studied in this paper for the condition that the well completion method has been determined in the horizontal well of the long-well section. The compatibility of the injected water with the reservoir and the fluid is studied, and the main water source type and the water quality index of the H oil field are counted according to the standard in the petroleum and natural gas industry. And different water quality standards are required for different formation conditions through core flow experiments. Due to the difference of the water quality of the water injected by the seawater and the conventional water injection, the method and the item for seawater pretreatment are summarized and summarized. The key factor of protecting oil well casing is the reasonable water injection pressure. In this paper, it is found that pipe loss and pressure loss of water nozzle are the main factors of water injection pressure loss. And the reasonable water injection pressure of the pipe column with the injection rate of 8000 bbl/ d and 6000 bbl/ d under the condition of 8000 bbl/ d and 6000 bbl/ d, respectively, is calculated by the reasonable water injection pressure formula. The Mishruf carbonate reservoir has the characteristics of deep burial depth, large thickness, strong heterogeneity, high injection quantity of single well, multiple well-and-well distance and well-type diversity of the surrounding affected oil well. Therefore, the tracer is put into the water injection well, the existence of the injected water in the oil reservoir, the direction of motion, the flow velocity, the relation between the plane and the longitudinal communication, the influence parameters, the distribution of the pore, the evaluation of the water drive effect, and the like, and the dynamic parameters of the water injection can be obtained through the follow-up monitoring. Through the comprehensive comparison and analysis and demonstration evaluation, the first pilot wells M279, M306 and M325 in the Mishruf reservoir are recommended to be the preferred tracer for the tracer. And the experiment of the tracer in the fresh water and the experiment in the seawater can find that the recommended three inorganic salt water-soluble chemical tracers are compatible with each other. According to the water injection characteristics of the horizontal well, the water injection of the horizontal well is divided into three sections from the wellhead to the formation, the relation model between the yield and the pressure difference of each section is established according to the flow characteristics of each section, and the calculation method of the injection pressure is summarized by using the principle of the node analysis. According to the theoretical formula, the water injection pressure is the pressure + total friction generated by the bottom hole pressure-liquid injection of the water injection well, and the computer model for calculating the water injection pressure in the horizontal well is developed.
【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】：TE357.6

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