WEYBURN, Saskatchewan – In what is being billed as the most significant discovery in the oil and gas industry’s modern history, a research group with multi-national oil and gas giant NextWell Corp has realized a practical means to fracture reservoir rock by using diet soda and Mentos.
The idea behind this new method, called Wellbore Fluid Expansion Fracturing by Cola and Mentos Reaction (or WFEF-CMR), is that the reservoir rock is parted by the force of wellbore fluids expanding by a chemical reaction between a cola based liquid and the Mentos (while the wellhead is shut-in). The lead scientist in this research, Dr. Rodolfo Ellis, discusses how the idea came to be:
“We are very excited about this finding. The genesis of this idea came from watching America’s Funniest Home Videos with my 11 year old son. I saw some kid drop a entire roll of Mentos into a 2L bottle of soda, and the bottle shot off roughly 100′ into the air. I thought to myself if only we could harness this force for good, and fracking was the first application that came to mind.” – Dr. Ellis
In the WFEF-CMR technique, see figure below, pressure is controlled by the ratio of Mentos to soda. As you can imagine, the higher the ratio, the higher the pressure. In order to better control the fracture process, to limit over-fracking the formation, the wellhead is equipped with a special pressure relief valve that is set to open at a pressure set just below the maximum fracture pressure. This valve is setup to minimize the chance that fracture tip propagation is limited to stay within frac design specifications.
“When we first experimented with this concept in an old, suspended observation well, we used regular cola and Mentos. But since we released too many Mentos, the relief valve opened and the frac fluid sprayed on the wellhead and area, creating a sticky, sticky mess. After figuring out that it was the sugar that was causing the stickyness, we decided to use diet soda and voila, problem solved.”
This new fracking practice promises to reduce the amount of water required for any fracking operation, including multi-staged horizontal fracs in unconventional reservoirs. Furthermore, the equipment required at the lease is significantly reduced to a simple tanker truck full of diet soda and a case of Mentos. Using a generic diet soda enables the cost per frac to come down even more.
The next step for Dr. Ellis and his team is to assess how well this technique applies to horizontal wells, and to see if it applies to complex multi-stage frac completions.