摘要
针对超长封固段低压易漏层顶替压力高、固井风险大、易发生漏失和憋泵等问题,研制了新型低密度水泥减轻材料SXJ-1,并进行了现场应用。利用缩聚反应得到了改性环氧树脂并与活性SiO2、固化剂等复配开发出了新型低密度水泥减轻材料SXJ-1;以SXJ-1为减轻材料,根据紧密堆积理论,通过加入早强材料XC-1及具有水化活性的复合增强材料XE60S,配制出密度为1.3~1.5kg/L的实心微珠低密度水泥浆,评价了该水泥浆的基本性能,分析了压力与搅拌速度对其密度的影响。结果表明,该水泥浆具有良好的基本性能,随压力及搅拌速度变化其密度也会发生变化,但其变化量在0.03kg/L以内,且性能无明显变化,具有良好的承压能力及抗剪切性能。电镜扫描试验显示,该水泥浆形成的水泥石结构致密,无明显破碎渗水现象,有利于提高水泥石的综合性能。配制的水泥浆已在胜利油田应用30余井次,全部实现单级固井一次返至井口的目的,合格率达到100%。研究认为,新型低密度水泥减轻材料SXJ-1具有良好的承压能力及抗剪切性能,用其配制的实心微珠低密度水泥浆能够解决超长封固段低压易漏层的固井难题。
Low-pressure formations susceptible to circulation lost in ultra-long cementing intervals are characterized by high displacing pressures,high cementing risks,frequent lost circulation,pump choking and other problems.Under such circumstances,an innovative low-density cement lightening material,SXJ-1,has been developed and applied in the fields.Through condensation polymerization,modified epoxy can be generated and be used in combination with active SiO_2,curative agent and other materials to generate low-density cement lightening material,SXJ-1.With SXJ-1 as the lightening material and in accordance with the theory of close packing,setting accelerator XC-1 and the composite reinforcing material,XE60S with hydrate activity have been used to prepare low-density cement slurry with densities of 1.3-1.5kg/L composed of solid beads.In the subject study,the basic performances of the cement slurry were evaluated along with the impact of pressures and agitation speeds on densities.Assessment tests resulted in outstanding primary performance with the cement slurry.Densities of the slurry may vary with changes in pressures and agitation speeds,but the fluctuations can be controlled within 0.03kg/L.With no significant changes in performances,Further,these slurries displayed outstanding pressure-bearing and anti-shearing capacities.SEM tests showed that the cement concretions formed by the slurry have high bond integrity,with tight structures showing no obvious cracking or water seepage.Generally speaking,the material can effectively promote overall performances of the cement concretions.Prepared cement slurry has been applied in over 30 wells in Shengli Oilfield.Cement returned to wellhead in one trip with success rate of 100% for all these wells.Research results showed that the innovative low-density cement lightening material,SXJ-1,possesses outstanding pressure-bearing and anti-shearing capacities.The low-density cement slurry composed by solid beads prepared by the lightening material can effectively meet the challenges in cementing operations in low-pressure cementing intervals susceptible to lost circulation.
出处
《石油钻探技术》
CAS
CSCD
北大核心
2017年第4期59-64,共6页
Petroleum Drilling Techniques
基金
国家科技重大专项课题"胜利油田特高含水期提高采收率技术"(编号:2016ZX05011-002)资助
关键词
减轻材料
低密度
水泥浆
长封固段
固井
lightening agent
low density
cement slurry
long cementing interval
well cementing
