OU researchers developing shale gas reservoir simulator

January 5, 2011

University of Oklahoma researchers are developing a new simulator for shale gas reservoirs that will provide oil and gas companies with an essential tool for managing production and choosing drilling locations to lower costs and increase production.

OU professors Richard Sigal, Faruk Civan and Deepak Devegowda, Mewbourne College of Earth and Energy, are the first to systematically tackle this challenge. The project is supported with $1,053,778 from the Research for Partnership to Secure Energy for America plus an additional $250,000 in matching funds from a consortium of six oil and gas producing companies.

Natural gas has a smaller effect and is less polluting than other , plus gas produced from shale gas reservoirs can have a positive impact on the U.S. economy by replacing coal used for , natural gas imports and oil imports in some applications.

"Simulators for conventional reservoirs are not suited for shale gas reservoirs," says Sigal. "An example of this is the deposition of frac water used to force the gas from the reservoir. In a shale gas reservoir, massive opens up the reservoir so the gas can flow. This involves pumping a large amount of water into the reservoir. In conventional reservoirs all this water is produced back, but in shale gas reservoirs only a small percentage of the water is produced."

According to Sigal, "Current commercial simulators do not successfully predict the amount of water produced. Researchers need to model the deposition of this water to better understand the reservoir and address concerns the effects this water can have on shallow aquifers. One goal of the simulator project is to determine and provide the capacity to model frac water deposition."

"Predicting long-term gas production with history matching requires more accurate physics and geology," states Sigal. "Using a new $2 million microscope at OU to see the detailed of the rocks, Professor Carl H. Sondergeld and his collaborators have found two kinds of pore space in the rocks. Besides the inorganic pore space where we expect to find gas, they discovered pores the size of nanometers in the organic portion of the rock. This discovery needs to be incorporated into the simulator design."

OU researchers recognize the physics of fluid flow and storage are very different in the inorganic and the organic portions of shale gas reservoirs. And, these reservoirs contain both natural and induced fracture systems each with different properties. OU researchers will develop a quad porosity model to take into account these differences.

There are three basic issues with the physics of these natural non-porous systems. First, the standard equations used to describe gas transport are incorrect in the small pores in the organic material where a significant portion of the hydrocarbon gas is stored. Researchers studying artificial nanomaterials have developed new gas transport equations that need to be adapted to the complicated pore spaces that describe shale gas reservoirs.

Secondly, in standard simulators, an assumption known as instantaneous capillary equilibrium provides the relationship between the gas and water pressure. Equilibrium cannot be maintained because of differences in the transport rates for water and gas in shale gas reservoirs, so the standard equations must be modified. Finally, the very large capillary forces caused by the very small pore size require a different treatment of relative permeability, which controls the relative transport of the water and gas.

"This is a three-year project to develop the new simulator starting with the fundamentals," Sigal remarks. "We have already developed a 1-D model. The next step will be to build a simple 3-D testbed system. At first, we will test this model against models run on commercial simulators."

"Next, we will build modules that incorporate the individual modifications needed for conventional simulators to correctly model shale gas reservoirs," Sigal comments. "These modules will be available for adoption by industry for use in existing company or commercial simulators. Finally, we will use the modified simulators to history match production from existing reservoirs. Our commercial sponsors will provide data for this."

Explore further: Researchers use sound to search for gas, oil

Related Stories

Researchers use sound to search for gas, oil

September 7, 2006

Just as doctors use ultrasound to image internal organs and unborn babies, MIT Earth Resources Laboratory researchers listen to the echoing language of rocks to map what's going on tens of thousands of feet below the Earth's ...

Carbon sequestration field test begins

May 16, 2007

The U.S. Department of Energy says its Midwest Geological Sequestration Consortium has started its first enhanced oil recovery field test in Illinois.

Process could clean up water used in natural gas drilling

March 12, 2010

(PhysOrg.com) -- Texas A&M Engineering is playing a role in a technological breakthrough that could clean up the contaminated water recovered from drilling natural gas wells in shale deposits through the process of "hydraulic ...

Hundreds attend EPA hearing on Pa. gas drilling

July 22, 2010

(AP) -- Hundreds of people are attending a U.S. Environmental Protection Agency hearing in southwestern Pennsylvania on a controversial natural gas drilling technique called hydraulic fracturing, or "fracking."

'Hydraulic fracturing' mobilizes uranium in marcellus shale

October 25, 2010

Scientific and political disputes over drilling Marcellus shale for natural gas have focused primarily on the environmental effects of pumping millions of gallons of water and chemicals deep underground to blast through rocks ...

Recommended for you

Interactive tool lifts veil on the cost of nuclear energy

August 24, 2015

Despite the ever-changing landscape of energy economics, subject to the influence of new technologies and geopolitics, a new tool promises to root discussions about the cost of nuclear energy in hard evidence rather than ...

Smart home heating and cooling

August 28, 2015

Smart temperature-control devices—such as thermostats that learn and adjust to pre-programmed temperatures—are poised to increase comfort and save energy in homes.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.