涠西南油田结垢机理及除垢工艺研究

发布时间：2018-05-29 19:42

本文选题：硫酸钡 + 结垢机理　；参考：《西南石油大学》2015年硕士论文

【摘要】：涠西南WZ油田已开发各油藏主力储层以中孔、中低渗透储层为主。储层物性较差,存在较强的敏感性、无机结垢现象突出,在钻井、完井、采油及修井过程中易于受到损害,致使许多井达不到配产要求,严重制约了油田高效开发。但由于结垢伤害和污染机理不明确,目前还没有有效的治理措施。为了有效解决WZ油田低效井治理的问题,延长油田稳产期,同时也为其它油田开发积累一定的经验和技术。本文以理论分析、室内实验、数学模拟为主要研究手段,系统深入涠西南WZ油田生产作业过程中结垢机理、结垢程度、范围,除垢机理与除垢工艺技术研究,取得的主要认识如下：。 (1)根据涠西南WZ油田实际的生产作业情况,充分利用X衍射、SEM定点扫描、能谱分析以及室内动态驱替等现代先进实验分析手段,深入分析了WZ油田的结垢类型、结垢机理。结果表明,WZ油田注采作业过程中均易结垢,且以硫酸钡垢为主,并伴随有一定的碳酸钙垢。修井作业过程中,修井液漏失速度快,结垢程度更为严重。 (2)针对修井液漏失流动特征,充分考虑成垢离子间的反应以及物质间的对流与扩散,建立了修井作业过程中硫酸钡结垢伤害数学模型。结合室内实验获得了模型所需基础参数,可实现对硫酸钡垢伤害程度、伤害范围有效预测。采用饱和指数法以及ScaleChem软件对油田碳酸钙结垢趋势进行了预测。结果表明,硫酸钡结垢主要发生在距井筒半径1.2米范围内；在储层条件下,地层水与海水混合碳酸钙结垢趋势明显。 (3)针对WZ油田结垢特征,充分考虑除垢剂的特点,采用溶蚀除垢法与粒径分析相结合的方法,筛选了一种具有螯合及分散双重作用的高效硫酸钡除垢剂。并采用室内动态实验评价了除垢剂-酸液体系综合除垢效果。结果表明,除垢剂-酸液体系协同作用,具有良好除垢效果。 (4)根据前期的室内实验和模拟结果,设计了一套针对涠西南WZ油田除垢工艺,并选取WZ-J2井进行了现场试验,解堵作业后,油井产量有了显著提升,验证了配方与工序的可靠性。本论文完成的研究内容以及取得的研究成果,为有效治理WZ油田的无机结垢伤害,恢复提高单井产能,提供了有力的技术支持。也为解决类似油田的复产提供了可借鉴的技术思路。
[Abstract]:The main reservoirs developed in WSW WZ oilfield are medium porosity and low permeability reservoirs. Reservoir physical properties are poor, there are strong sensitivity, inorganic scaling phenomenon is prominent, in drilling, completion, oil recovery and workover process is easy to be damaged, resulting in many wells can not meet the requirements of production, which seriously restricts the efficient development of oil fields. However, due to the unclear mechanism of fouling and pollution, there are no effective control measures. In order to effectively solve the problem of low efficiency well treatment in WZ oilfield, prolong the stable production period of oil field, and accumulate certain experience and technology for other oilfield development at the same time. In this paper, theoretical analysis, laboratory experiments and mathematical simulation are used as the main research methods to study the scaling mechanism, scaling degree, range, scale removal mechanism and scale removal technology of WZ oil field in Wei Southwest China. The main knowledge gained is as follows:. 1) according to the actual production situation of WSW WZ oilfield, the scaling types and scaling mechanism of WZ oilfield are analyzed by using modern advanced experimental analysis methods such as X-ray diffraction SEM fixed spot scanning, energy spectrum analysis and indoor dynamic displacement. The results show that barium sulfate scale is the main scaling during injection and production operation, accompanied by calcium carbonate scale. During workover operation, the fluid leakage rate is fast and the scaling degree is more serious. (2) considering the leakage flow characteristics of workover fluid and considering the reaction between scaling ions and the convection and diffusion between materials, a mathematical model of barium sulfate scaling damage during workover operation is established. The basic parameters of the model are obtained by the laboratory experiments. The damage degree and damage range of barium sulfate scale can be predicted effectively. The saturation index method and ScaleChem software are used to predict the scaling trend of calcium carbonate in oil field. The results show that barium sulfate scaling mainly occurs within 1.2 meters from wellbore radius, and the formation water and seawater mixed calcium carbonate scaling trend is obvious under reservoir conditions. According to the scaling characteristics of WZ oilfield, a high efficiency barium sulfate scale remover with double functions of chelating and dispersing was selected by using the method of corrosion and scale removal combined with particle size analysis, taking full account of the characteristics of scale remover. The scale removal effect of scale removal agent-acid system was evaluated by laboratory dynamic experiments. The results showed that the synergistic effect of scale remover and acid solution system had good scale removal effect. (4) according to the laboratory experiment and simulation results, a set of scale removal technology for WSW WZ oilfield is designed, and the field test is carried out by selecting WZ-J2 well. After plugging removal, the oil well production has been remarkably improved, and the reliability of formula and working procedure has been verified. The research contents and results obtained in this paper provide powerful technical support for the effective control of inorganic scaling damage in WZ oilfield and the recovery and improvement of single well productivity. It can also be used for reference to solve the problem of recurrence of similar oilfields. Technical thinking
【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】：TE358.5

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