A cement interface enhancer and its action mechanism

Abstract

A cement interface enhancer (CIE) to improve the well cementing quality for fresh water-based drilling fluid was prepared and its action mechanism was studied. The composition and the proper dosage of CIE were studied with mud cake strength test and steel plate immersion test. CIE contained inorganic mineral fibers such as calcium silicate, silica nanoparticles, and low polarity polymers; the proper proportion was about 1.8:1.2:1. The cementing strength simulation experiments showed that the cementing strengths of the interfaces between the cement and the wellbore casing (the first interface), and the cement and the borehole wall (the second interface) were increased by three and four times, respectively, when 0.8 % (weight) of CIE was added into the drilling fluid. This was due to the support effect, inductive effect, and electrostatic repulsion of CIE, and the bonding of cement with mud cake was improved. The application of CIE in Daqing Oilfield showed that the cementing perfection rate could be increased by 30 % that indicated CIE could improve the well cementing quality effectively.