PRRC Receives Grant to Study Oil Chemistry

by George Zamora

[The Petroleum Recovery Research Center (PRRC) is part of a consortium that has received $1.1 million for a study aimed at improving oil recovery.]

SOCORRO, N.M., Feb. 9, 1999 -- New Mexico Tech's Petroleum Recovery Research Center (PRRC) has been chosen to spearhead a multi-disciplinary study on how the flow of oil through a reservoir is affected by the interactions between formation fluids and mineral surfaces.

A research team comprised of scientists at New Mexico Tech, the University of Wyoming, and Texas Tech University recently was awarded $1.1 million by the National Petroleum Technology Office (NPTO) to explore how "wettability" -- the ability of a solid surface to attract or repel water, oil, or other fluids -- influences both the amount of oil that can be produced and the rate of oil production. NPTO is the Tulsa-based arm of the U.S. Department of Energy which supports oil recovery research projects in several areas at the PRRC.

Matching funds, provided by New Mexico Tech ($675,000) and by the University of Wyoming, put the total amount over $1.8 million for conducting the three-year study.

"We're expecting to shed more light on the complex factors controlling reservoir fluid flow, allowing oil producers to improve computer simulation models and to develop better oil recovery processes" says Jill S. Buckley, principal investigator of the study. Buckley serves as head of the Petrophysics and Surface Chemistry Group at the PRRC.

"Reservoir wettability is influenced by the composition of the oil, the mineralogy of the rocks, and even by the composition of the water or brine in an oil reservoir," Buckley explains. "We have to understand the interactions among all of these factors in order to get a clearer picture of how wettability affects fluid flow."

For example, in a "waterflood" -- a very common oil recovery practice in which water is injected into a reservoir to maintain pressure and displace oil -- success or failure can depend on wettability. Work leading up to this study suggests that wettability is especially affected by very large compounds -- known as "asphaltenes" -- which are dispersed in crude oils. The extent to which these molecules affect wettability can vary to a surprising degree, depending on the composition of the rest of the oil.

Characterizing the chemistry of the oil will be the responsibility of New Mexico Tech chemistry professor Christopher Palmer. The PRRC researchers will focus on relating the oil chemistry to wetting alteration of mineral surfaces.

Buckley and Palmer will be joined in the study by Professors Norman Morrow of the University of Wyoming's chemical and petroleum engineering department and P.K. Dasgupta from Texas Tech University's chemistry department. Morrow will be in charge of a research team which will concentrate its efforts on the effects of wettability on displacement of oil from rock samples; while Dasgupta will be responsible for developing a new analytical technique for studying asphaltenes.