Research Aims to Improve Natural Gas Production
4/27/2011 - Missouri University of Science and Technology
ROLLA, Mo. – Natural gas is an abundant energy resource for
the United States, but much of it remains trapped in shale or
Researchers at Missouri University of Science and Technology
hope to develop a way to extract that gas by studying the energy
source at the molecular level.
Dr. Baojun Bai, assistant professor of petroleum engineering, is
leading the research, which involves looking at how natural gas
behaves in these constricted environments.
Working with Bai is Dr. Yinfa Ma, Curators’ Teaching
Professor of chemistry, whose single-molecule imaging system will
allow the researchers to examine the flow properties of natural gas
on a small scale.
The U.S. Geological Survey estimates that tight sands and shale
formations may hold up to 460 trillion cubic feet of natural gas,
enough to meet current U.S. demand for nearly 21 years.
According to the Natural Gas Supply Association, Americans
consume about 22 trillion cubic feet of natural gas a year.
But traditional methods of extracting natural gas will not work in
these tight formations, Bai says.
“The problem is that the pore size is so small – only a few
nanometers,” he says.
In conventional natural gas reservoirs, the
gas flows through pores that are a few micrometers in width.
The difference between nanometers and micrometers is significant. A
single nanometer is one billionth of a meter.
A micrometer is one
millionth of a meter. That means that a micrometer is 1,000 times
larger than a nanometer.
At the nanometer scale, materials behave differently. No one really
knows how natural gas flows at that level, Bai says.
So he, Ma and
some Missouri S&T graduate students are trying to find out.
“We want an improved understanding of how the gas flows through the
pore space – specifically, how natural gas in a nanoscale pore
behaves,” Bai says.
“The flow behavior will be different than the conventional
behavior, but we don’t know how exactly.”
“With the novel single-molecule imaging system I designed, we can
directly monitor the flowing behavior of natural gas, polymer
solutions and surfactants in nano-pores, individually or
simultaneously,” Ma says.
“This can be used for new flow model developments and
correlated with mathematical models developed by our project
The S&T researchers will also study how the materials used to crack
shale in tight formations in order to extract natural gas – the
fluids, polymers and surfactants – will affect gas flow.
“We want to find out how to reduce the polymer and
surfactant impact on the formation,” Bai says, “because its impact
on the formation impacts the gas flow.”
The project is funded through a three-year, $1.2 million grant from
the Research Partnership to Secure Energy for America under a U.S.
Department of Energy contract.
Through this grant and other funding from research partners,
Bai and Ma’s team will study the effect of introducing those
materials on “natural gas transportation properties” such as
capillary pressure (the force required to squeeze natural gas
through a pore), absolute and relative permeability (how well the
gas flows through minerals), and non-Darcy flow (which results in
Much of the work will take place in Ma’s laboratory, where the
researchers will use Ma’s single-molecule imaging system to
construct a 3-D model of pores in, for example, a shale natural gas
First, however, they will examine cross-sections of shale by
using Missouri S&T’s focused ion beam microscope, or FIB, which is
capable of magnifying objects up to a million times their actual
The shale samples will come from S&T’s partners on the project: two
Houston-based firms, Baker Hughes (formerly BJ Services) and Hess
Corp., and other shale-gas operators.
Once they have the FIB-created images of the pores from shale
cross-sections, they will reconstruct the cross-sections to create
their 3-D model.
“I expect that we can create a new mathematical model to predict the
gas flow through the nano-level pores,” Bai says.
In addition, Bai and Ma hope to “comprehensively characterize the
pore distribution in the shale, because not all of the rock is
homogeneous,” Bai says.
The research should prove useful to the natural gas industry, says
Bai, whose background is in enhanced oil recovery.
Working with Bai and Ma on the project are Malek Elgmati, a graduate
student in petroleum engineering; Yongpeng Sung and Hao Zhang, both
Ph.D. students in petroleum engineering; and Qihua Wu, a Ph.D.
student in chemistry.
In addition to the $1.2 million RPSEA grant, the project is
supported through Baker Hughes, Hess Corp., Missouri S&T and the
Colorado School of Mines.