By KEN MILAM
EXPLORER Correspondent

Texas Aim/DOE Projects Make Progress

DOE Grants

When the U.S. Department of Energy announced several grants for natural gas recovery research, Texas A&M University received three – more than any other single institution – and officials say they are progressing well.

The projects, all funded over 36 months, include:

• Developing new methods for creating extensive, conductive hydraulic fractures in unconventional tight gas reservoirs. After assessing a wide range fracture treatments conducted in the field, researchers will develop design models for implementing optimal fracture treatments. DOE’s share of the cost totals $1.2 million.
• Developing efficient tools and a systematic work flow for improved oil reservoir characterization and modeling. The technology will be demonstrated in a CO2 flood in the Permian Basin of West Texas. DOE’s share is $785,846.
• Incorporating current and emerging technologies into a clean, environmentally-friendly drilling system that can be used to find and produce natural gas in the lower 48 states. The project also includes establishing a joint venture of industry, academic and government partners to support development of such a zero-impact drilling system. DOE is contributing $1.4 million.

“The goal is to develop improved practices for hydraulic fracturing of tight gas sands through experimental evaluation of fracture conductivity and gel damage effects, critical evaluation of current fracturing processes and modeling of gel clean up and damage,” said professor A. Daniel Hill, principal investigator for the fracturing project.

Work began in the spring with three faculty members, a post-doctoral researcher and four graduate students, Hill said.

“Field tests are planned in the third phase of the project, if results to that time are favorable,” Hill said.

Asked how the work would advance the state of the art, Hill said the project will develop guidelines for hydraulic fracture fluid selection to optimize tight gas fracturing at a wide range of temperatures.

The new practices should help cut costs – “majors, independents and service companies can all benefit,” Hill said

Improved Reservoir Models

Professor Akhil Datta-Gupta leads the reservoir characterization project along with Bill Milliken of Chevron’s Production Technology Center.

“The potential impact of this research will be improved reservoir models and performance forecasting and significant cost savings. Better characterization of petroleum reservoirs will result in better management and field development strategies, leading to increased oil recovery.

“A 5 percent incremental recovery from the existing domestic oil fields will result in over one billion barrels of additional oil,” Datta-Gupta said.

“The focus of this proposal is to develop efficient tools and a systematic workflow for improved reservoir characterization and model updating via field-scale dynamic data integration,” he said. “A concurrent objective is to assess the uncertainty in physical property models and reservoir parameters at various scales.”

The proposed approach will be orders of magnitude faster than current techniques – days as opposed to months – making the technology accessible to small operators.

“The method has broad applicability (primary depletion, waterflood/gas injection and three-phase flow below bubble point pressure) and preserves all relevant geologic constraints,” he added.

The team plans to demonstrate the method’s practical feasibility using field application to a CO2 injection pilot project in West Texas followed by a detailed model validation.

“The highly heterogeneous carbonate reservoirs in the Permian Basin represent one of the largest CO2 floods in the world,” he said. “The CO2 injection projects are plagued by early gas breakthrough and low sweep efficiencies, leaving large scope for optimization and additional recovery. Much of this can be attributed to our inability to characterize the high permeability channels, flow paths and barriers in the reservoir.

“Integration of dynamic data early in the geologic model building can greatly alleviate the situation,” Datta-Gupta said.

The research is co-funded by a number of industrial sponsors as part of the Joint Industry Project – Model Calibration and Efficient Reservoir Imaging (www.pe.tamu.edu/mceri/).

“Because of this joint effort, we have developed a number of novel technologies/algorithms that have found widespread use in the oil industry,” he said. “The DOE funding will help us continue to do that at a faster pace.”