For many years, Gilsonite has been used in the oilfield as an additive in drilling fluids. Gilsonite, in various grades and formulations, has been used to combat borehole instability problems, provide lubricity, especially in highly deviated holes, and more recently as a bridging agent to combat differential pressure sticking and provide a law invasion coring fluid. It has been well documented that appropriately formulated Gilsonite products can minimize hole collapse in formations containing water-sensitive, sloughing shales and reduce stuck pipe problems by forming a thin wall cake and an inter-matrix filter cake.
Gilsonite products are currently being widely used in water based, oil based, and synthetic based mud systems worldwide. Blended Gilsonite has proved to be very effective in all water-based systems.
The main difference between the application of Gilsonite in OBM(Oil Based Mud) and WBM (Water Based Mud)is how Gilsonite is added to the drilling fluid system. While it can be added directly in both applications, some people add Gilsonite to a WBM system in a solution with glycol usually referred to as “liquid” Gilsonite
SIGNIFICANT COST ADVANTAGES
Compared to alternative products, Gilsonite offers comparable or superior performance at a much lower cost. In water-based mud (WBM) applications, Gilsonite’s performance compares favorably with sulfonated asphalts while costing 25-50% less.