摘要
渤海L油田Ed储层油井修井后产液能力显著降低,储层伤害严重。针对这一问题,研究了现场修井液的储层伤害机理,开发了1种低伤害修井液。研究表明,现场修井用的Ng地层水与Ed储层地层水混合有严重结垢趋势,且Ed地层水比例越大、储层温度越高,结垢趋势越明显。优选XCF-03作为修井用防垢剂,药剂浓度超过25 mg/L后,结垢量可由117.2 mg/L降至3.6 mg/L以下,阻垢效果十分明显。Ed储层为强水敏储层,伊/蒙间层黏土矿物含量高达23%。在Ng地层水中加入0.5%KCl可以抑制Ed储层黏土的膨胀。以Ng地层水+25mg/LXCF-03+0.5%KCl为配方的修井液对Ed储层伤害率小于5%,储层保护效果明显。
Well productivity declines drastically and reservoir damage is grave after workover in the Ed reservoir of Bohai L oilfield.The mechanism of reservoir damage due to workover fluid has been studied and a less harmful workover fluid has been developed.The study shows that Ng formation water used for workover has a strong scaling tendency when mixed with Ed reservoir water,and the higher proportion of Ed water and the higher temperature of Ed reservoir,the more likely the scaling tendency will be.The XCF-03 has been optimized as an inhibitor.When inhibitor concentration exceeds 25 mg/L,the amount of scale buildup reduces from 117.2 mg/L to under 3.6 mg/L,showing remarkable effect of scale inhibition.The Ed reservoir is highly water-sensitive,with illite/smectite interstratified clay minerals(I/S) up to 23%.Adding 0.5% KCl into Ng formation water can inhibit clay swelling in Ed reservoir.The workover fluid with such a formula as Ng formation water + 25 mg/L XCF-03 + 0.5% KCl has a damage rate to Ed reservoir of < 5%,showing good reservoir protection effect.
出处
《特种油气藏》
CAS
CSCD
北大核心
2013年第2期134-136,158,共3页
Special Oil & Gas Reservoirs
基金
国家油气重大专项"海上油田注入水综合治理技术研究"(2008ZX05024-002-11)
关键词
修井液
伤害机理
防垢剂
储层保护
强水敏储层
Ed储层
渤海L油田
workover fluid
damage mechanism
scale inhibitor
reservoir protection
highly water-sensitive reservoir
Ed reservoir
Bohai L oilfield
