油井水泥石增强用材料的制备与性能评价

Preparation and Performance Evaluation of Reinforced Material for Oil Well Cement

橡胶颗粒表面的亲水性差、与水泥胶结性欠佳,作为弹性粒子用于固井会降低水泥石的抗压强度。为改善现有技术的不足,以二苯基甲烷二异氰酸酯、聚环氧丙烷二醇、硅酸盐水溶液、重质碳酸钙等为原料制备了一种多相颗粒材料,并对其结构进行了表征。在水泥中加入多相颗粒制得水泥浆或水泥石,评价了水泥浆的流变性、稳定性和水泥石的力学性能。结果表明,多相颗粒主要呈现两种结构。第一相为多孔洞状连续相,第二相呈球状。多相颗粒中第二相嵌合于第一相的孔洞之内,且球状第二相中含有19.6%的Si元素。与净浆水泥石相比,含多相颗粒的水泥石弹性模量低,强度基本保持。多相颗粒对水泥浆的稠化时间和流变性的影响较小。多相颗粒界面的球型结构含有的大量硅羟基参与或部分参与了水泥的水化,与水泥在界面处以化学键紧密连接,保证了水泥水化结构的连续性,弥补了橡胶弹性粒子与水泥石界面黏结力不足的缺陷。

The surface of rubber particle has poor hydrophilicity and poor cementation with cement,which will reduce the compressive strength of cement stone during cementing.In order to improve the shortcomings of existing technology,a heterogeneous granular material was prepared by diphenylmethane diisocyanate,polyepoxypropane glycol,silicate aqueous solution and heavy calcium carbonate.Its structure was characterized.The cement slurry or cement stone was prepared by adding multiphase particles into the cement.The rheology and stability of the cement slurry and the mechanical property of the cement stone were evaluated.The results showed that there were two main structures in multiphase particles.The first phase was a porous continuous phase,and the second phase was spherical.In the multiphase particles,the second phase embedded in the pores of the first phase,and the spherical second phase contained 19.6%Si.Compared with the cement stone,the cement stone containing multiphase particles had low elastic modulus and basically maintained its strength.Multiphase particles had little effect on the thickening time and rheology of cement slurry.The spherical structure at the interface of multiphase particles contained a large number of silicon hydroxyl groups,which participated or partially participated in the hydration of cement,and was closely connected with cement at the interface by chemical bonds,so as to ensure the continuity of cement hydration structure and made up for the defect of insufficient interfacial adhesion between rubber elastic particle and cement stone.