TARLIFT additive is a blend of solvents and surfactants that softens accreted tar without aggressively attacking the wellbore. Its balance of solvency, viscosity and surface active agents works well in low‐temperature tar sands.
TARLIFT blend is added to the SAGDRIL system or similar drilling fluids designed to reduce tar accretion to the bottomhole assembly and shaker screens. It is added directly to the circulating system at concentrations from 0.1 to 2% by volume. Because tar deposits vary in viscosity and stickiness, final concentrations must be determined by performance in the field. TARLIFT blend typically is used in combination with TARSURF surfactant and inorganic agents to assure complete water wetting of the softened tar and metal surfaces.