长庆超低渗储层注水井用油溶性分流剂的性能与应用评价

Evaluation and Application of Oil-soluble Diverting Agent for Injection Well in Ultra-low Permeability Reservoir of Changqing Oilfield

由于受沉积韵律、储层物性、非均质性等影响,长庆油田每年吸水不均井占比超35%,严重影响生产井组动态。针对以上问题,以姬塬油田超低渗储层为研究对象,自主研发了一种适合近井地带剖面调整的油溶性分流剂WS-2,室内测试了其溶解性、耐温性、分散性、粒度、封堵效率和解堵性能,并进行了现场试验。研究表明,分流剂WS-2在酸溶液和水中均不溶而易溶于煤油,软化点在120℃左右,粒径30数100 um。WS-2分散性能好、遇携带液呈悬浮状,便于注入地层,对岩心的封堵效率在90%以上,可满足现场应用。针对尖峰状和指状吸水不均井使用油溶性分流剂WS-2,平均吸水厚度增加2.5 m,平均水驱动用程度提高8%,3个月后生产井组动态稳定,达到了注水井剖面调整的目的。油溶性分流剂WS-2在同类的油藏中具有推广使用的前景。图6表3参14。

Due to sedimentary rhythm,reservoir property and heterogeneity,uneven profile well of Changqing oil field is over 35%in recent years,which has severely disrupted well production.To solve these problems,Jiyuan oilfield of ultra-low permeability reservoir as the research object,an oil soluble diverting agent WS-2 for profile correction near wellbore area was developed,and its solubility,temperature tolerance,dispersion,particle size distribution and plugging performance was tested in lab,the field test was carried out.the results showed that the diverting agent WS-2 was insoluble in water and acid solution,and was soluble in kerosene,the softening point of WS-2 was at about 120℃,the particle size was 30—150μm.The WS-2 had good dispersion performance and could suspend in the carrier fluid,which was conducive to be injected into the formation.The plugging efficiency of SW-2 to the core was over 90%,meeting the demand of the field application.Aiming at the peak and the finger shape of uneven water wells,the diverting agent WS-2 was applied and achieved good results.The average water absorption thickness increased by 2.5 m,the average degree of water drive increased by 8%,and production well group maintained stability after three months,realizing the injection profile adjustment.The diverting agent WS-2 has a bright prospect in the same kind of reservoir.