低密度高炉矿渣水泥浆固井技术

A STUDY ON LIGHTWEIGHT BFS CEMENT SLURRY CEMENTING TECHNOLOGY

针对长庆油田低压易漏地层团井水泥浆返高和固井质量存在的问题，用高炉矿渣、膨润土设计密度１．４０～１．６０ｇ／ｃｍ３的矿渣膨润上水泥浆，用矿渣和钻井液设计密度１．４０～１·６０ｇ／ｃｍ３的矿渣ＭＴＣ浆，用矿渣和多功能钻井液设计密度互１．４０～１．６０ｇ／ｃｍ３的矿渣ＵＦ浆。对三种低密度矿渣水泥浆的抗压强度、凝结时间、流变性和稳定性进行了试验研究。室内研究结果和现场试验结果表明，三种低密度矿渣水泥浆水泥石抗压强度高，水泥浆流变性好，体系稳定。低密度矿渣膨润土水泥浆现场施工方便，固井质量优质率平均约８０％。低密度矿渣ＭＴＣ浆和矿渣ＵＦ浆现场施工有局限性，但其对提高固井质量的技术优势必将引起固井界人士的关注和研究应用。

In accardance with the inadequate, cement slurry top and the poor cementing quality in low pressure thief zones ofChangqing Oil Field, three BFS cement slurry systems(BFS-bentonite,BFS-MTC and BFS-UF) with a density range of 1. 40~1. 60g/cm^3 have been developed. These three light weight cement slurry systems have been examined on their compressivestrength, setting time, rheology and stability respectively. Laboratory experiments and field tests showed that the light weightsystems results in high cement sheath compressive strength,excellent rheology and system stability. The light weight BFS/bentonite cement slurry can be easily applied to oil field,with hight cementing quality of about 80%. Whereas field application oflight weight BAS/MTC and BFS/UF is limited their advantages to improve cemeting quality which will inevitably arise the interest of cementing enginneers.