CHARACTERIZATION AND PERFORMANCE EVALUATION OF VARIOUS TYPES OF POLYMERS BASED LATEXES FOR WATER BASED DRILLING FLUIDS APPLICATIONS

Polymer based latex chemicals are primarily used as fluid loss additive in drilling fluids. They are used to prepare a thin filter cake on the wellbore formation and reduce filtrate loss into the formation. A thin filter cake reduces or eliminates incidences of differential stuck drill pipes. The objective of this study is to look into two different polymer latexes for the use of water-based drilling fluids applications. The first polymer is based on Styrene-butadiene latex. The second polymer is based on Polyvinyl Acetate emulsion, (PVA). Analytical techniques such as nuclear magnetic resonance (NMR) spectroscopy, Fourier transform infrared analysis (FTIR), differential scanning calorimeter (DSC), and thermogravimetric analysis (TGA) were used to help in elucidating the structures and physical properties of different latexes. Tests such as for density, rheology, HT/HP filtration and thermal stability were conducted to compare the performance of different latexes in drilling fluid formulations. Intensive analytical and performance evaluation were done on different types of latexes to find proper way of latex optimization for application for water-based drillings fluids. Styrene butadiene polymer latex outperforms several polymers due to the strong anionic interaction with formation compared to other mechanisms.