The purpose of this proposal is to verify that the use of fly ash instead of cement in the plugging of abandoned oil and gas wells, water wells and seismic holes is a viable option. Long-term objectives are to provide a cheaper, environmentally friendly, and more economical method of plugging wells. The objectives of this project are to obtain the cementitious properties of Class C fly ash from five coal-fired power plants in Oklahoma and, utilizing these properties, to produce a fly ash grout similar to cement grout. Furthermore, the ability to pump this slurry through coiled tubing to place a plug of fly ash grout will be proven. The end result will be to utilize a fly ash grout for plugging of abandoned oil, gas, and water wells rather than a cement grout. The research will be divided into two phases: (1) laboratory analysis of samples of the fly ash from selected power plants and development of optimum grout formulations, (2) the pumpabiltiy of these formulations through coiled tubing and straight pipe will be proven and the frictional properties investigated.