Performance of carbonate calcium nanoparticles as filtration loss control agent of water-based drilling fluid

Abstract

Application of nanoparticles in improvement of drilling fluid properties through effective control of fluid loss and rapid formation of thin, smooth and low permeable filter cake has gained considerable attention in recent years. In this study, calcium carbonate nanoparticle was synthesized by precipitation method and characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscope (SEM), dynamic light scattering and Zeta-potential measurement. Water based bentonite drilling fluid was used as base fluid. Various concentrations of calcium carbonate nanoparticle (0.025–0.5 wt%) was added to water-based drilling fluid. Fluid loss volume, filter cake thickness and its surface morphology, and rheological properties of both base fluid and fluid containing calcium carbonate nanoparticles was measured and compared. Results show that addition of calcium carbonate nanoparticle greatly affects filtration properties and forms smoother cake surface. Optimum concentration of 0.07 wt% calcium carbonate nanoparticle was obtained which results in reduction of fluid loss volume and filter cake thickness by 26% and 64% respectively while minor change in rheological behavior was observed. SEM image showed smoother cake surface of drilling fluid with calcium carbonate nanoparticle as additive compared to base drilling fluid. Considerable improvement in filtration properties using acid soluble CaCO3 nanoparticles can help in minimizing fluid leak-off and formation damage of producing layers and more effective well cleanup for fast oil and gas production.