摘要
苏北油田阜三段油藏油井易出砂、井筒易结蜡,致使地层近井地带污染堵塞严重,油井产量突降。采用土酸、多氢酸等单级酸酸化解堵工艺均存在酸化效果差、恢复时间长、有效周期短、不能较好地恢复产能。鉴于该问题,筛选出适合溶解有机垢的KD-54B高效清洗剂,通过电离、缓冲、溶蚀、抑制二次沉淀等室内实验,研制出HD-2新型复合酸体系。该复合酸体系主要由不同比例的盐酸、有机多氢酸、多种表面活性剂等组成,具有有效溶解石英、抑制酸体和黏土的反应、抑制酸岩反应过程中二次及三次沉淀、缓速与深穿透的特点。同时确定1%防膨剂+3%碳酸钠作为顶替液,酸化工艺模式为70℃高效清洗剂热循环洗,依次挤入KD-54B前置段塞液、HD-2新型复合酸主酸液及顶替段塞液后关井。该工艺在阜三段油井解堵中应用效果显著,如NH2-17井酸化后累增油245 t,有效期458 d;CT111-1井累增油240 t,有效期540 d;J2-7-10井累增油482 t,有效期251 d。
The oil wells of the third member of the Funing Formation in the Subei Oilfield are prone to sand production and wax formation in the wellbore,which leads to severe pollution and blockage in the near wellbore area and the sudden decrease of oil well production.The single-stage acid plugging removal process,such as mud acid and polyhydrogen acid,has poor acidizing effect,long recovery time,and short effective period,and cannot restore the production capacity relatively well.For this problem,the KD-54B efficient cleaning agent suitable for dissolving organic scale was selected,and a new HD-2 composite acid system was developed through laboratory experiments such as ionization,buffering,dissolution and inhibition of secondary precipitation.The composite acid system mainly comprises different ratios of hydrochloric acid,organic polyhydroic acid,various surfactants,etc.It has the characteristics of effective dissolution of quartz,inhibition of the reaction between acid body and clay,inhibition of secondary and tertiary precipitation,slow speed,and deep penetration in the process of acid rock reaction.At the same time,1%anti-swelling agent+3%sodium carbonate was determined as the displacement fluid,and the acidizing process mode was hot cycle washing with 70℃high efficient cleaning agent.The well was shut down after squeezing in the KD-54B pre-slug fluid,HD-2 new type of composite acid as the main acid,and the displacement slug fluid in turn.The application effect of this technology in oil wells of the third member of the Funing Formation is remarkable,such as NH2-17 well,the cumulative oil increase after acidizing is 245 t,with an effective period of 458 d;the cumulative oil increase of CT111-1 well is 240 t,with an effective period of 540 d,and the cumulative oil increase of J2-7-10 well is 482 t,with a validity period of 251 d.
作者
吕海威
LYU Haiwei(Taizhou Oil Production Plant of East Oil and Gas Company,SINOPEC,Taizhou 225300,China)
出处
《复杂油气藏》
2024年第2期246-252,共7页
Complex Hydrocarbon Reservoirs
关键词
油井
解堵
复合酸
酸化
配套工艺
应用效果
oil well
plugging removal
compound acid
acidification
matching technology
application effect
