Ven-Rez I™ is a chrome-free lignite derivative engineered with a potassium ion designed to provide improved filtration control and stabilize rheological properties in high temperature water base muds. Ven-Rez I™ is based on a new lignite derived resin. It is compatible with most water-based drilling mud additives. Ven-Rez I™ is particularly effective as a high temperature fluid loss additive in water-based systems. Ven-Rez I™ is water soluble and is not designed for use in oil-based mud systems. Ven-Rez I™ can be used to thin almost all types and densities of water-based drilling fluids. In addition, it will function as an effective emulsifier in oil-in-water muds and will provide some emulsification and dispersing properties for liquid lubricants. Ven-Rez I™ can be used to stabilize salt-contaminated muds.