复合型膨胀增韧剂的研究与应用

RESEARCH AND APPLICATION OF COMPOUND EXPANSIVE&FLEXIBLE AGENT

针对温北油田油气井水泥石高收缩、高脆性带来的固井质量问题,制备了一种油井水泥复合型膨胀增韧剂(代号EF35),并利用该剂开发了一套适用于温北油田油层套管固井的膨胀增韧型水泥浆体系。实验结果表明:EF35的膨胀率达1.5%,弹性模量降到7 GPa;水泥浆的可混拌性与流变性良好,各性能指标均满足现场施工要求。经温北油田7口井的现场检验,一、二界面的固井质量合格率均达到100%,平均优质率达94.52%。

In response to the challenges faced by a batch of oil and gas wells in the northern part of Wensu Oilfield,such as poor cement bonding and unacceptable isolation of cross layer key areas,after in-depth analysis,it is believed that the high shrinkage and low mechanical stress performance of setting cement are the common reasons for the failure of the above work.To address the challenges encountered,EF35 was developed based on several rounds of optimization and selection tests,with an expansion rate of 1.5%and a reduction of 7 GPa in elastic modulus.Based on this,a targeted composite expansion and flexible slurry system suitable for this field has been proposed.The slurry samples showed satisfactory performance through laboratory testing.In addition,ideal miscibility,good rheological properties and other performance data could be maintained throughout the entire cementing process.The adhesion between the casing-cement interface and the cement-formation interface was evaluated as qualified for 7 consecutive job positions on site,with 94.52%rated as good cement adhesion.