【作者】 朱红旺；

【导师】 赵立强；

【作者基本信息】 西南石油大学 ， 油气田开发工程， 2013， 博士

【摘要】 本文以鄯善油田为研究对象,通过分析影响制约单井注入能力的主要原因；剖析伤害机理,确定伤害范围；建立酸化井层选择模型；建立裂缝性油藏酸化模型；提出高效增注工作液体系,最终形成配套增注工艺技术。具体完成工作如下：(1)通过系统分析注水井注入压力升高,欠注严重的原因,提出地质构造、井间连通性、储层物性、钻完井伤害、转注井伤害、注入条件变化是导致注水井投注初期注入压力高的主要原因；而注入水水质、粘土伤害、投注与增注措施伤害等综合因素的影响导致注水井投注后压力升高；(2)采用模糊物元分析方法,通过综合考虑渗透率、有效孔隙度、表皮系数、注水层厚度、连通性、实注系数、吸水指数减小幅度7种评价指标,建立了专门针对注水井酸化的井层选择模型。其中连通性、吸水指数减小幅度是以往类似模型尚未考虑的。并通过对鄯善油田10口注水井的实例计算,验证了本模型的有效性,得出结论与实际相符,可为酸化方案优化提供理论依据；(3)通过大量实验研究了盐酸、氢氟酸与砂岩矿物反应机理,并结合提高解堵效果及减小酸化二次伤害的出发点,提出一种新型砂岩酸化酸液体系—FTC酸体系。酸度特性试验、溶蚀试验、缓蚀性评价试验、驱替实验、微观孔隙结构评价试验等表明该体系具有良好的缓速、缓蚀、抑垢等特点,是一种性能优良的低伤害、深穿透酸液体系；(4)选用较易由流动实验取得并能反映地层水和地层实际情况的经验参数,基于微粒捕集机理,根据经典渗滤模型(对流方程),结合岩心实验数据,对模型进行半解析求解,模拟了油田注水伤害程度和伤害半径；(5)通过获取储层裂缝分布数据,生成和储层裂缝在统计意义上等效的离散裂缝网络,引入渗透率张量原理将裂缝性致密砂岩储层转化为均质各向异性储层,结合“两酸三矿物”酸岩反应模型,建立了天然网络裂缝储层酸化综合模型；(6)针对储层地质特点及技术实施条件,提出泡沫分流酸化工艺和化学微粒分流酸化工艺,并研制了与之配套的泡沫酸液及注水井酸化化学分流剂,室内性能评价结果表明,两种分流酸化技术分流效果好、对地层无伤害、现场实施方便；(7)考虑储层参数及液体室内试验结果,基于模拟计算,为现场施工提供了理论依据充分、实用性强的施工参数确定方法和一般范围,研究成果指导现场酸化施工4井次,酸化后均取得良好的降压增注效果,酸化成功率均达到100%。本论文所取得的系列研究成果为鄯善油田注水井实现解堵增注提供了理论支撑与技术保障,对酸化技术在注水井中的应用提供了一定的理论依据和研究思路,进一步丰富和完善了裂缝性油藏砂岩酸化相关模拟研究,弥补了目前国内外注水井酸化理论与技术研究中存在的不足。更多还原

【Abstract】 Shanshan oilfield is taken as the research object in this paper. The main reasons of low injection rate are analyzed; The damage mechanism and damage range of injection well are determined; A selection model of wells and layers in injection well acidizing and an acidizing model of fractured reservoir are established; An efficient acid system is proposed. Eventually, a set of efficient injection stimulation technology is come into being. Specific work is as follows:(1) By systematically analyzing the reasons of the high injection pressure and low injection rate in injection wells, it is proposed that the geological structure, connectivity, reservoir properties, drilling and completion damage and the change of injection condition are the main reasons that lead to high injection pressure in the early injection stage. While the injecting water’s quality, clay damage and the damage caused by stimulation or other factors lead to the increasing pressure after injection;(2) Using the fuzzy matter element evaluation method and by considering permeability, the effective porosity, skin factor, layer’s thickness, connectivity, real injection coefficient and injectivity index reduction, a model to select acidizing layers specially for injection wells is set up. Besides, the connectivity and injectivity index reduction haven’t yet been considered in the previous similar models. By calculating ten injection wells in Shanshan oilfield as an example, this model is verified valid and the conclusion is consistent with the actual situation, which can provide the theoretical basis for acidizing optimization;(3) The reaction mechanism of hydrochloric acid, hydrofluoric acid and sandstone mineral is studied by numerous experiments. Aimed at effectively improving the plug removal effect and reducing the acidification secondary damage, a new acid system--FTC acid system for sandstone acidizing is proposed. The acidity characteristics test, dissolution test, corrosion inhibition evaluation test, displacement test and microscopic pore structure evaluation test show that the acid has good retarder, corrosion inhibition and anti-scaling characteristics, which is an excellent acid system with low damage and deep penetrating.(4) Based on the empirical parameters, which can reflect the actual situation of the formation water and the formation, particulate trap mechanism, and classical percolation model (convection equation), the damage degree and radius after injection in the oilfield is simulated combined with the experimental data of cores. The model is solved by semi-analytical approach.(5) By obtaining reservoir fracture distribution data, equivalent discrete fracture networks and permeability tensor, the fractured tight sandstone reservoir is transferred into homogeneous anisotropic reservoir. Then acidizing simulation in natural network fracture reservoir is realized based on the mature model of two acids and three minerals.(6) In order to achieve the acid distribution and facilitate the safe and effective implementation, the foam diversion and chemical particles diversion acidizing technology is proposed. And the diverting agent with good shunt effect, no damage to stratum and on-site implementation is developed.(7) According to the reservoir parameters, laboratory test results and the simulation result, the determination method of practical construction parameter and the general scope are provided. The research findings have guided field acidizing treatments four times, which achieves a good acidizing effect and with the successful rate of100%.In this paper, the series of research results provide theoretical basis and technical support for plug removal and injection stimulation in injection well of Shanshan oilfield. Furthermore, it provides certain theoretical basis and research approaches on acidizing technology in injection wells, which enriches and improves the related acidizing simulation study in the fractured sandstone reservoir. Also, the deficiencies of the current research on the theory and technology of injection well acidizing at home and abroad are made up.更多还原