摘要
砂岩酸化技术是油气井稳产、增产,注水井降压、增注的主要工艺措施之一,目的是通过酸液在地层孔隙的晶间、孔隙及微裂缝中的流动和反应,来溶解井眼附近地层在钻井、完井、修井及注水等过程中的各种固相微粒、杂质,解除其对地层渗透率的伤害,疏通流体渗流通道,从而恢复和提高单井的产能。
本文针对JZ25-1S 油气田高孔高渗油田开发的特殊性,并结合海上酸化作业的难点,开展了这类油藏储层伤害机理和类型、增产机理、优选酸液体系、酸液分流技术、酸化工艺参数优化等研究。通过研究对酸化机理及其影响因素有了全面认识,筛选出了适合JZ25-1S油气田的酸液体系和适合的酸液分流技术并对施工参数进行优化。工艺技术、酸液体系的研究成果最终形成了实用的高孔高渗非均质砂岩油藏酸化对策和配套酸化工艺技术,对国内外类似砂岩储层酸化都有借鉴。
关键词:酸化模拟;砂岩酸化;储层伤害;酸化工艺;基质酸化
Abstract
Matrix acidizing of the sandstone is one of the technical measures to stabilize or increase the production of a oil or gas well, lower the injection pressure and enhance the injection of a injection well. The aim is to dissolve the particle and impurity in the formation near the wellbore caused by drilling, workover and water injection, through the flow of acid in the pore, cavity and microcrack in the formation, so as to relieve the formation damage, dredge the flow channel, thus recover and enhance the production.
Aimed at the formation particularity of JZ25-1S oil and gas field, combined the difficulty of offshore acid, this paper presents the research of reservoir damage mechanism and types,the mechanism of stimulation, optimizing the acid fluid system, acid diversion technique, optimizing acid technology parameter. Through the research, we have fully understanding about acid mechanism and the damage factor, and we select the appropriate acid system and acid diversion technique, optimize construction parameter for JZ25-1S. The research accomplishment of acidizing technology, acid fluid system and not only formed practical sandstone acidizing countermeasure and complex acidizing technology and technique in BOHAI oil field, but also provided some experiences for the similar conditions in the whole world.
Key words: acid simulation; sandstone acid; formation damage; acid technology; matrix acid