Development of an Environmentally Friendly and Economical Process for Plugging Abandoned Wells

EPA Grant Number: R83-0633-010
Title: Development of an Environmentally Friendly and Economical Process for Plugging Abandoned Wells
Investigators: Subhash Shah
Institutions: University of Oklahoma
EPA Project Officer: Bala Krishnan
Project Period: May 1, 2003 to April 30, 2004
Project Amount: $ 135,803
Research Category: Plugging of abandoned wells

Description:

ABSTRACT

The purpose of this project 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 Phase I of the project were 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. Phase I has been completed in which the optimum fly ash slurry formulation was developed, tested, and compared with Class H cement. The results showed that the fly ash plug can be substituted for Class H cement for well plugging.

Phase II objective is to finalize the acceptability of fly ash slurry as plugging material. Additional laboratory tests are planned to further determine the quality and bond strength of fly ash grout. Furthermore, hydraulic bond strength tests and shear bond strength tests will also be conducted and they will be followed by actual field application tests. The optimization of placement technique will then be established for the achievement of high quality fly ash plugging for abandoned wells.