摘要
注水开发的长庆低渗油藏地层结垢严重，20世纪90年代通过钻10口结垢检查井揭示了地层结垢特点，据此开发了依次注入吸附型防垢剂和螯合型除垢剂的地层清防垢技术。所用防垢剂是含铁离子稳定剂的膦酸盐复配物NTW-3，在油砂上吸附后可长期起防垢作用，工作液浓度一般不低于1％。所用除垢剂有主要针对钙垢的CQ-1和后期的CQ-3，主要针对钡锶垢的Remval Ba，工作液浓度一般不低于10％，前者应较高，后者应较低。1991～2006年在47口油井实施注入NTW-3＋CQ-3（或CQ-1）或＋Removal Ba的清防垢作业，42口井增油，有效期平均11．4月，详细介绍了4个井例，包括2口中等和中低渗井和2口特低渗井。特低渗西峰油田2001年开始注水，注水压力高达11．5～15．0MPa，注水半年后注水井吸水指数下降；岩心实验表明注入0．05％NTW-3＋10％Removal Ba或CQ-3可解堵，2002-2004年在6口注水井实施清防垢解堵，使吸水指数趋于稳定，有2口井的有效期超过2年。图3表5参4。
Severe scaling problems in pay layers were and are encountered in water flooded oil reservoirs of low permeability in Changqing. Taken into consideration the state of scaling ascertained through drilling 10 detective wells in 1990s, a stratum scale removing/inhibiting technology is developed, involving squeezing adsorptive scale inhibitor （ASI） and chelating scale remover （CSR） successively into the aimed strata. The ASI used is N TW-3, a phophinate compouned with iron ion stabilizer, commonly squeezed in ≥1% aqueous solution and exerts scaling control in pay layers in a long time being adsorbed on rocks. The CSRs used are CQ-1 in the early stage and CQ-3 in later mainly for removing Ca salt scale and Removal Ba mainly for removing Ba/Sr salt scale and are squeezed commonly in ≥10% aqueous solution, more concentrated in cases of Ca scale and less concentrated in cases of Ba/Sr scale. In 1991- 2006, stratum scale removing/inhibiting operations with NTW-3 ＋ CQ-3（CQ-1） or NTW-3 ＋ Removal Ba were performed in 47 production wells and resulted in increase in oil output in 42 wells in 11.4 months in average. 4 wells, 2 of middle and middle-low and 2 of ultra-low permeability, are presented as samples. In Xifeng oil field of ultra-low permeability, water flood started in 2001 at high injection pressures, 11.5-15.0 MPa, and watertake index in injection wells dropped down in 0.5 year; core tests showed good blockage relieving results of squeezing 0.05% NTW-3 ＋ 10% Removal Ba or CQ-3; stratum scale removing/inhibiting operations for injectivity enhancement were performed in 6 water injection wells and led to stabilization of watertake index with a positive response time 〉2 years in 2 wells of 6.
出处
《油田化学》
CAS
CSCD
北大核心
2007年第2期179-184,共6页
Oilfield Chemistry
基金
国家"西部开发"科技行动计划重大攻关项目"陕甘宁盆地特低渗油田高效开发与水资源可持续发展关键技术研究"(项目编号2005BA901A13)部分内容
关键词
地层结垢
钙垢
钡锶垢
防垢剂
除垢剂
采油井
注水井
清防垢技术
低渗透油藏
长庆油田
综述
formation scaling
calcium carbonate/sulfate scale
barium/strontium sulfate scale
scale inhibitor
scale remover
production wells
water injection wells
scale removing/inhibiting technology
low permeability oil reserwirs
Changqing oil fields
review
