US Patent 7572382 Recycling hydrocarbon hydraulic stimulation fluid

Hydrocarbon stimulation fluids are often used to increase the permeability and productivity of oil and gas reservoirs. The fluid itself is made up of a mixture of hydrocarbons and various chemicals designed to induce gel formation and gel breaking. The successful removal of these chemicals from the fluid has been achieved, through a process of acid-washing, mixing with a settling agent, centrifugation and filtration. This will allow the fluid to be re-used many times for further fracturing processes.