低成本防窜水泥浆体系固井技术

Cementing technology of low cost channeling control cement slurry

针对安塞油田和靖安油田的调整井、底水油藏井、油气水层活跃井和不平衡压力下的油气水窜固井难题,研制出了GJR-1低成本防窜油井水泥浆外加剂,它由铝酸盐聚合物GJL、微膨胀材料GPZ、强触变性材料GCB和高效减水剂GJS组成。室内对GJR-1低成本防窜油井水泥浆的稠化时间、抗压强度、线性微膨胀率以及抗温性能的评价表明,该水泥浆具有低温高早强、短过渡、微膨胀、强触变的特性。现场应用表明,该水泥浆促凝作用明显,可降低顶替水泥浆的泵压,提高顶替效率;过渡时间短,增加了抗窜阻力;做触变性和内聚力高;早期抗压强度高;水泥浆硬化后具有一定的微膨胀性,可防止微裂缝、微裂隙的形成,有效地改善第一、第二界面的胶结质量,防止环空界面窜流。采用该体系固井600多口,油层段固井合格率为100％,优质率超过90％。

Low cost channeling control cement slurry additive GJR-1 has been developed to cope with oil, gas and water channeling problems of cementing in adjustment wells, bottom water reservoir wells, oil-gas-water active wells and underbalanced pressure wells in Ansai and Jing'an oilfields. The additive is composed of aluminate polymer GJL, micro-expanding material GPZ, strong thixotropy material GCB and high efficient water reducer GJS. The thickning time, compressive strength, linear micro-expanding rate and thermal resistance performance of GJR-1 base cement slurry have been evaluated in laboratory and the results showed that the slurry has such properties as strong early strength in low temperature, short transition time, micro-expanding and strong thixotropy. Field applications indicate that because of the above factors, the cement slurry acts obviously accelerating, and by using it, displacing pump pressure can be depressed and displacing efficiency can be increased. Meanwhile, because oil/gas/water channeling can be a-void and fracture/micro-fissure forming can be prevented, cementing quality of two bond surfaces can be improved effectively. In addition, the cement slurry is cheaper than other cement slurries. It has been used in about 600 wells, and 100% of cementing success rate and over 90% excellent rate in oil layer have been obtained.