Rheological study on the invert emulsion fluids with organoclay at high aged temperatures

Publication date: Available online 20 April 2019Source: Colloids and Surfaces A: Physicochemical and Engineering AspectsAuthor(s): Tie Geng, Zhengsong Qiu, Chunhua Zhao, Li Zhang, Xin ZhaoAbstractInvert emulsion fluids stabilized by organoclays are important for applications in thixotropic fluids and petrochemical industry, especially in the field of oil extraction. Among these applications, improvement of the rheological properties of invert emulsion fluids at high temperatures lacks detailed study. In the current work, three different organoclays, including organo-sepiolite (OSEP), organo-hectorite (OSHCA) and organo-montmorillonite (OMMT) were prepared through chemical modification of unmodified clays using DODMAC. The results of X-ray diffraction (XRD) and scanning electron microscopy (SEM) show that DODMAC is not only adsorbed on the surface of particles, but also inserted into the layers of OMMT and OSHCA. For OSEP particles, DODMAC can only be adsorbed on the surface of particles. Interestingly, the results of optical microscopy and rheology indicate that the OSHCA particle-stabilized invert emulsion fluid provides better rheological properties than the other two organoclays at high temperature. Such high rheological properties is ascribed to the weak flocculation of OSHCA particles. Due to its nonreactive Mg-OH surface groups, OSHCA maintains the rheology of high-temperature aged invert emulsions by reconstructing weak flocculation structure. On the other hand, on the...

Source: Colloids and Surfaces A: Physicochemical and Engineering Aspects - April 22, 2019 Category: Chemistry Source Type: research