Plug and Abandonment, P&A, operation is inevitable for each and every well. Most oil and gas wells are plugged at lowest cost possible complying with requirements set by regulatory agencies. Geopolymers can be used as an alternative material for P&A operations. Unlike many other alternatives such as resin, they are cost efficient and easy to pump down the wellbore. They can be mixed easily onsite and activated by addition of an alkali activator. The research presented in this paper shows they can have a good pumpability, low shrinkage, and high compressive and shear bond strength.
The Geopolymer mixtures in this work were composed of Class F Fly Ash rich in Silicate and Aluminum, with elements of Potassium, Calcium, Iron, Sodium, and Titanium. A mixture of Sodium Hydroxide and Sodium Silicate was used to activate the Fly Ash mixtures. Geopolymer mixture designs tested in this work showed high compressive strength, low shrinkage, and suitable thickening time for applications in well abandonment. In addition, these alternative P&A materials can be produced cheaper with less environmental impact, which is a proper fit in the applications oil and gas well cementing.