The performance of polymer beads in water-based mud and its application in high-temperature well

Abstract

The major concern in multilateral drilling is the torque and drag that arises as we drill deeper coupled with the escalation of bottomhole temperature, which can be overcome through the use of a lubricant: a solid or liquid form. Solid lubricants have been proved to be able to reduce the coefficient of friction substantially. In this research work, polymer beads were used as a lubricating agent in a high-temperature condition. The polymer beads which possessed improved physical properties were constructed using polymerization of styrene monomer added with divinylbenzene. The molecular structure and thermal properties of the polymer beads were evaluated using Fourier transform infrared analysis (FTIR) and thermogravimetric analysis (TGA), respectively. The lubricity test was conducted on four different types of sample, namely oil-based mud, water-based mud, and water-based mud with polymer and glass beads, at temperatures ranging from 60 to 180 °C. The experimental results were found to give an average reduction of 27.5 % of coefficient of friction at elevated temperature and the rheological properties experienced slight changes above 100 °C as compared to water-based mud. In a nutshell, the polymer beads show the potential to be used as a lubricating agent in high-temperature conditions.