暂堵实现选择性堵水和酸化一体化技术研究与应用

【作者】 王雷；

【导师】 赵立强；

【作者基本信息】 西南石油学院 ， 油气田开发工程， 2005， 博士

【摘要】 本文针对渤海高孔高渗非均质砂岩油藏开发过程中存在的问题,即由于层间非均质性使油井层间矛盾加剧,高渗层出水严重,而相对低渗层在开发过程中受到污染,其间的油很少或几乎未被动用。采用单一的堵水和酸化作业均不能明显改善层间非均质矛盾,反而会使低渗层在堵水中受到伤害,而高渗层在酸化中渗透率进一步加大。由于在堵水过程中堵液会不可避免的进入非目的层并对其造成伤害,同时堵水过程中由于高渗层内大孔道的存在,堵液沿大孔道段突进,造成了堵液的大量损失。针对上述问题提出了一种暂堵实现选择性堵水和酸化一体化技术。论文完成的主要工作有: Ⅰ 针对这项技术对堵剂的性能要求,研制了一种成胶时间可控、注入性好、成胶强度大、耐酸性较强的堵剂体系,通过采用两种添加剂在地下一定温度条件下生成交联剂可以明显控制成胶时间,通过添加一种可以与溶液中H~+发生配位结合的配位剂,可以明显增强堵剂的抗酸性; Ⅱ 针对使用的堵剂体系建立了进入深度简化模型,对堵液笼统注入过程中在非目的层的进入程度和形成的伤害进行了研究,分析了层间渗透率级差、地层流体粘度比、以及堵液阻力系数和残余阻力系数对伤害程度的影响,并对能够减小非目的层伤害的选择性注入工艺进行了阐述,提出了适合堵酸一体化技术要求的暂堵技术; Ⅲ 针对高孔高渗非均质油藏特殊的储层条件以及本技术的特点,采用酸溶性悬浮颗粒体系作为堵水前的暂堵剂。暂堵剂主要起两个作用:首先利用高渗层的层内非均质性,暂堵剂进入到高渗层内后可以通过沉降作用降低高渗层内大孔道的孔隙度,并且可以在高渗层中的小孔道内形成堵塞,从而增加了后续注入堵剂的作用距离,提高了堵水的有效性;其次在相对低渗层端面快速形成暂堵带,从而减少堵剂进入相对低渗层的程度和堵液对非目的层造成的伤害。通过实验得到悬浮颗粒直径与非目的层平均孔隙直径之间可以形成最优桥堵的比值,在桥堵基础上利用更小的颗粒作为填充粒子,通过复合填充并在一定压力下可以在非目的层快速形成致密暂堵带,并且这种暂堵剂在酸化过程中可以绝大部分被去除; Ⅳ 根据储层特征和伤害特点优选出适合高孔高渗非均质砂岩储层的酸液体系以及与之相配套的添加剂体系,对于高孔高渗油藏酸化首选氟硼酸体系为主酸液体系,为了增强对堵塞物的有效溶解可考虑土酸和复合酸体系,通过岩心流动实验确定采用盐酸和氟硼酸复合酸液体系; Ⅴ 对暂堵堵水酸化工艺进行了研究,对堵剂和酸液的注入速度和注入强度的影响因素分别进行了分析,推荐了典型储层条件下堵液、酸液注入速度和注入强度范围。最后通过两口井的实例证明这种技术改善高孔高渗非均质油藏的开发效果是明显的,应进一步推广应用。更多还原

【Abstract】 During the development of high permeability and interlayer heterogeneous sandstone reservoir, serious heterogeneity leads into the increasing interlayer conflict.one hand the high permeability layer produces much water, on the other hand the relative low permeablity layer is contaminated during development and the inner oil is hardly produced. According to the above situations and taking the contaminantion during water shutoff into account the dissertation put forward the temporary protective water shutoff and acidizing integrated technology. The dissertation involves the blow contents:I Accoding to the technology requirments for plugging agent, the dissertation has developed an underground polymerizing and crosslinking plugging agent, it bears the blow merits:good injectivity, larger strength and stonger acid resistance;II The dissertation has studied the damge to low permeability layer during the gelant general injection. It has analysed the below factors that influence on the damage degree, these factors involve interlayer permeability ratio, fluid viscosity ratio, resistance factor and residual resistance factor so on. The dissertation has discribed the selective injecting technology and at last according to the integrated techonology has put forward the temporary protecting technology.III Adopting a kind of suspending grain as the temporary plugging agent,with experiments we has gotten the optimum ratio between average pore diameter and grain diameter that can form bridge blimding. And by adopting the larger bridge blimding grain and smaller filling grain it can quikly form the compact temporary plugging under higher pressure, in the end the temporary plugging can be removed by the acidizing.IV Based on the formation characteristics and damage mechanism the dissertation has optimized acid system and corresponding additive system. It has selectted fluorboric acid as the main acid, sometimes in order to enhance the contamination corrosion we can adopt the mud acid and complex acid, at last with the coreflooding experiments we decide the hydrochloric acid and fluorboric acid as the applied acid system.V The dissertation studies the injecting technology of temporary plugging water shutoff and acidizing integrated technology, and it has analyzed the factors that affect injecting velocity and injecting intensity of plugging agent and acid agent. And based on the special reservoir situation it has recommended the injecting velocity and injecting intensity range of plugging and acid agent. The well shutoff time and acid reaction time are also recommended.更多还原