硫铝酸盐固井水泥石-套管界面胶结强度增强机理

Reinforcement mechanisms of cementation strength at the interface between the casing and the sulpho-aluminate set cement

宋梅梅 窦益华 杨振杰 张勇 程凯凯

SONG Meimei DOU Yihua YANG Zhenjie ZHANG Yong CHENG Kaikai

西安石油大学机械工程学院 西安石油大学石油工程学院

College of Mechanical Engineering, Xi’an Shiyou University, Xi’an 710065, Shaanxi, China College of Petroleum Engineering, Xi’an Shiyou University, Xi’an 710065, Shaanxi, China

硫铝酸盐水泥是一种潜在固井材料，其固井界面胶结强度及微观结构尚不明确，为此进行硫铝酸盐水泥浆胶结界面胶结强度增强机理实验研究。采用X射线衍射仪研究硫铝酸盐水泥浆的水化机理，利用胶结强度测试装置测定硫铝酸盐水泥浆固井界面胶结强度，利用扫描电子显微镜和X射线能谱分析表征固井界面的微观结构及化学组分。研究结果表明：龄期为1 d、3 d、7 d时，硫铝酸盐水泥与套管的胶结强度比同龄期G级水泥分别提高了24.3%、20.1%和25.3%；微观分析结果表明，套管表面聚集着大量Al元素(AH₃凝胶)，其高聚合度可以降低界面处的孔隙率，从而提高硫铝酸盐水泥石的界面封固性能。

Sulpho-aluminate cement is a kind of potential cementing material, and its microstructure and cementation strength at the cementing interface have not been figured out. In regard of this, the reinforcement mechanisms of cementation strength at the cementing interface of sulpho-aluminate cement slurry were experimentally studied. The hydration mechanisms of sulpho-aluminate cement slurry were investigated by using the X-ray diffractometer, the cementation strength at the cementing interface of sulpho-aluminate cement slurry were measured by means of the cementation strength test unit, and the microstructure and chemical compositions at the cementing interface were characterized by virtue of scanning electron microscope (SEM) and X-ray energy spectrum analysis. It is shown that the cementation strength between the sulpho-aluminate cement and the casing at the age of 1 d, 3 d and 7 d is 24.3%, 20.1% and 25.3% higher than that of G-grade cement of the same age. The microscopic analysis result indicates that a large amount of Al element (AH gel) accumulates on the surface of the casing, and its high polymerization degree can decrease the porosity at the interface, so as to improve the interface cementing performance of sulpho-aluminate set cement.

10.13639/j.odpt.2019.01.008