Title: Development of an Environmentally Friendly and Economical Process for Plugging Abandoned Wells
Author(s): Subhash N. Shah, and Yeon-Tae Jeong, The University of Oklahoma
Presentation: The 10th International Petroleum Environmental Conference
Location:Houston, TX, USA
Date: November 11-14, 2003
Abstract:
Fly ash has long been known for its cementitious properties. Presently, however, cement grout is used for abandoned wells plugging. It has been shown in our previous research that the use of Class C fly ash as plugging material for the abandoned wells is an economically viable option. In that work the optimum fly ash slurry formulation was developed, tested, and compared with Class H cement. The results are very encouraging and it appears that the fly ash plug could be an economical substitute for cement.
The objective of this paper is to report the progress on continuation of the previous work using fly ash grout. In this study, results of the additional laboratory tests with fly ash slurry as plugging material will be reported. These tests include frictional pressure loss tests, wellbore fluid contamination and compressive strengths tests, gas permeability tests, and hydraulic and shear bond tests. The correlations derived from these tests will also be presented. Frictional pressure loss data will be from 1 ½-in. coiled tubing as well as straight tubing of the same size. Various fly ash grout placement technique using the coiled tubing will also be discussed. The plan for performing field tests with the optimum fly ash formulation and the technique will also be addressed.
