强碱三元复合驱堵塞原因分析及解堵技术实验研究

发布时间：2018-01-29 12:02

  本文关键词： 大庆油田 强碱三元体系 储层适应性 解堵方法 注入工艺　出处：《东北石油大学》2015年硕士论文　论文类型：学位论文

【摘要】：大庆油田三元复合驱取得了良好“稳油降水”效果,目前已经进入工业化推广应用阶段。但在强碱三元复合驱实践中,由于储层参数不确定性和矿物组成复杂性,加之碱与储层矿物间的溶蚀作用,造成部分强碱三元体系注入井注入困难,给油田生产带来严重影响。为解决以上问题,本文以油藏工程、物理化学和高分子材料学为理论指导,以化学分析、仪器检测和物理模拟为技术手段,以杏树岗储层地质和流体为研究对象,开展了现有强碱三元体系与储层适应性评价和碱与储层岩石溶蚀作用及其对渗流特性影响研究。在此基础上,进行了注入井堵塞物组成分析、堵塞物对储层吸液能力影响和解堵方法研究。结果表明,强碱三元复合体系储层适应性受渗透率、非均质性、聚合物相对分子质量、聚合物浓度和剪切强度等因素影响。与杏六东部Ⅱ块油层相适应强碱三元复合体系聚合物参数:聚合物相对分子质量1200×104,浓度2000mg/L,或聚合物相对分子质量1900×104,浓度1500mg/L。随碱浓度增加、作用时间延长和“液:固”比增大,岩样与碱溶蚀作用程度增加。与单纯碱液相比较,“碱/表面活性剂”二元体系和“碱/表面活性剂/聚合物”三元体系对岩样溶蚀程度较弱,表明表面活性剂和聚合物可以减轻碱对岩样溶蚀作用。在碱与岩样溶蚀过程中,Ca2+和Mg2+浓度降低,表明有碳酸盐沉淀生成,这是造成孔隙过流断面减小和渗流阻力增加的重要原因。聚合物相对分子质量与油层孔喉配伍性差以及碱与地层矿物反应而出现结垢现象是造成注入困难的主要原因,解堵技术难度较大。注入井中存在堵塞物是造成注入困难的另一原因,因堵塞物主要滞留在近井地带,采用少量解堵剂就可以解除堵塞作用。优化注入井堵塞物解堵剂配方:氧化剂(0.4%ClO2)+复合酸(12%HCl+3%HF+1%CH3COOH+0.6%小阳离子季铵盐+0.5%KCl+0.5%YC-SY)。推荐现场注入顺序为:氧化剂→复合酸。
[Abstract]:The ASP flooding in Daqing Oilfield has achieved a good effect of "stabilizing oil and precipitation" and has entered the stage of industrialization and application at present, but in the practice of strong alkali ASP flooding. Due to the uncertainty of reservoir parameters and the complexity of mineral composition, coupled with the dissolution between alkali and reservoir minerals, it is difficult to inject some strong alkali ternary system injection wells. In order to solve the above problems, this paper takes reservoir engineering, physical chemistry and polymer materials as the theoretical guidance, chemical analysis, instrument detection and physical simulation as the technical means. Taking Xingshugang reservoir geology and fluid as the research object, the existing strong alkali ternary system and reservoir adaptability evaluation, alkali and reservoir rock dissolution and its influence on percolation characteristics are studied. The composition of plugging matter in injection well is analyzed and the influence of plugging material on reservoir fluid absorption ability and plugging method are studied. The results show that the reservoir adaptability of strong alkali ternary system is influenced by permeability and heterogeneity. The relative molecular weight of polymer, polymer concentration and shear strength are affected. The polymer parameter of polymer system is 1200 脳 10 ~ 4 relative molecular weight, which is suitable to the oil layer 鈪，

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