连续气举采油设计方法研究

发布时间：2018-11-09 07:14

【摘要】：连续气举采油是气举采油方式的一种,这种人工举升方法的原理就是向油套环空中连续不断的注入高压气体,气体与井筒中的流体混合,致使井筒中混合物密度降低,从而导致井底流压降低,生产压差增大,将井筒中流体举升到地面的一种类似于自喷的举升方法。连续气举采油的适应范围很广,无论是流体性质、产量范围还是举升高度,连续气举都有着良好的适应性,具有以下技术特点：(1)产量适应范围广,在地面可实现产量调节；(2)运动部件少,寿命长,能实现三年不动管柱进行生产；(3)气举阀通过钢丝作业进行更换,检修方便；(4)相应的完井管柱可实现测试、压井和不压井作业；(5)适应环境能力强,不受砂、气、井斜以及恶劣的地表环境等因素的影响；(6)操作简单,生产容易实现集中化和自动化管理,运行成本低。一般,在进行连续气举采油前,需要进行气举设计。而气举设计离不开理论方法的指导,因此,对连续气举采油设计方法研究很有必要。而准确气举设计方法的研究需获得如下基本资料：井深、油、套管尺寸、油井生产条件、地面管线尺寸及长度或给定的井口油管压力,希望获得的产量、含水、注入气的相对密度、可提供的注气压力及气量、油井流入动态、油井温度、地面流动温度、地面原油密度、地层水密度、压井液密度、天然气的相对密度、地层静压、生产气油比和原油粘度等。上述各项资料中大多数将直接用于设计,个别项作为设计时参考使用。因此,气举设计方法是气举技术的关键内容,选择合适的设计方法,可使气举井以较佳的状态工作,实现气举井的产量最优化。本文研究了连续气举采油设计方法中最常用三种方法：可变流压梯度法、等注气压力降气举设计法和等关闭压力降气举设计法,并对这三种方法进行对比分析,然后用以等关闭压力降气举设计法为理论基础的PIPESIM来对Y油田的B地层进行气举方案设计。通过理论来指导实践,用实践来深化理论,使油井以最大产能生产。首先,对连续气举采油设计国内外现状进行调研；其次,研究最常用的三种气举设计方法,给出了这三种方法的设计过程以及适用条件等；然后,用等关闭压力降法对区块的油井进行气举设计。先对人工气举举升接替时机进行预测,在此基础上对注气压力进行优选以及对注气量进行预测,得出气举设计结果如布阀级数和布阀深度等。最后,进行气举优化配气,而气举动态曲线是优化配气的基础,对注气压力和井口压力进行敏感性分析,可以优化气举设计,最终提高产量和节约经济成本。
[Abstract]:Continuous gas lift oil production is one of the gas lift oil production methods. The principle of this artificial lifting method is to continuously inject high pressure gas into the oil ring air, and the gas is mixed with the fluid in the wellbore, resulting in the decrease of the density of the mixture in the wellbore. As a result, the bottom hole flow pressure is reduced, the production pressure difference is increased, and the fluid in the wellbore is lifted to the ground, which is similar to the self-blowout lifting method. Continuous gas lift oil recovery has a wide range of adaptation, whether fluid properties, production range or lift height, continuous gas lift has a good adaptability, with the following technical characteristics: (1) wide range of production adaptation, Yield regulation can be realized on the ground; (2) few moving parts and long life, which can realize the production of three years fixed pipe string; (3) the gas lift valve can be replaced by steel wire operation, and the maintenance is convenient; (4) the corresponding completion string can be used for testing, well killing and no well killing; (5) it has strong adaptability to the environment and is not affected by sand, gas, well inclination and bad surface environment. (6) it is easy to operate easily and realize centralized and automatic management, and the operation cost is low. In general, gas lift design is needed before continuous gas lift production. Gas lift design can not be separated from the guidance of theoretical methods, so it is necessary to study the design method of continuous gas lift oil production. And the research of accurate gas lift design method needs to obtain the following basic data: well depth, oil, casing size, production conditions, surface pipeline size and length or given wellhead tubing pressure, desired production rate, water cut, The relative density of the injected gas, the gas injection pressure and volume, the inflow performance of the oil well, the temperature of the well, the surface flow temperature, the density of crude oil on the ground, the density of formation water, the density of the fluid, the relative density of natural gas, the static pressure of the formation, The ratio of gas to oil and the viscosity of crude oil are produced. Most of the above information will be used directly for design, and individual items will be used as reference at design time. Therefore, the gas lift design method is the key content of the gas lift technology. Choosing the appropriate design method can make the gas lift well work in a better state and realize the optimization of the gas lift well output. In this paper, the three most commonly used design methods for continuous gas lift production are studied: variable flow pressure gradient method, equal injection pressure drop gas lift design method and equal off pressure drop gas lift design method, and the three methods are compared and analyzed. Then PIPESIM is used to design the gas lift scheme of B formation in Y oilfield based on the equal closing pressure drop gas lift design method. Through theory to guide practice, with practice to deepen the theory, so that oil wells to maximize production capacity. Firstly, the current situation of continuous gas lift oil recovery design at home and abroad is investigated. Secondly, the three most commonly used gas lift design methods are studied, and the design process and applicable conditions of these three methods are given. Then, the gas lift design of the oil well in the block is carried out by the equal closing pressure drop method. Based on the prediction of the replacement time of artificial gas lift, the optimal selection of gas injection pressure and the prediction of gas injection volume are carried out, and the gas lift design results such as valve distribution series and valve distribution depth are obtained. Finally, the gas lift optimization of gas distribution, and the gas lift dynamic curve is the basis of the optimization of gas distribution, gas injection pressure and wellhead pressure sensitivity analysis, can optimize the design of gas lift, and ultimately improve the output and save economic costs.
【学位授予单位】：长江大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE355.3

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