M-I Swaco, a Schlumberger company, has developed a water-based drilling system with engineering flexibility designed to help operators quickly and successfully address the challenges of shale plays, including their economic and environmental constraints. The novel, low-cost chemistry of the HydraGlyde high-performance water-based drilling-fluid system reduces torque, drag, shale swelling, and dispersion. It delivers a rate of penetration (ROP) comparable with that of oil-based mud, with optimal hole-cleaning characteristics and high levels of wellbore stability in high-angle build sections and long lateral sections. This is made possible with the company’s HydraSpeed ROP enhancer, which delivers lubricity that mimics that of oil-based mud. The system also delivers a high-quality filter cake and a low-tortuosity wellbore that minimizes the risks of differential sticking. The cost-effective HydraGlyde system addresses several challenges associated with shales, including accretion in the surface hole, wellbore instability, mud losses in the intermediate section, solids buildup, and hole cleaning in the horizontal section. A specially engineered primary shale inhibitor provides a high degree of wellbore stability, and a proprietary encapsulator minimizes clay dispersion and enhances wellbore integrity.