Washington,
DC - Technology developed under a U.S. Department of Energy–funded research
project has breathed new life into one of America's largest mature producing oilfields.
The project, managed by the Office of Fossil Energy's National Energy Technology
Laboratory (NETL), is expected to add ultimately 13 million barrels of incremental oil
production in a small portion of the Wilmington oilfield, a 73-year-old giant in the heart
of Long Beach, Calif. If new technologies and techniques developed under the project are
applied field-wide, it could boost Wilmington's ultimate oil recovery by 525 million
barrels of oil. That jump, in a single oilfield, equates to a 2.5 percent increase in
total U.S. proved oil reserves. An aggressive effort to transfer this technology could
boost reserves in similar fields along the California coast by 1.4 billion barrels of oil.
A small, independent producer, Tidelands Oil Production Co., operates the western portion
of the field as a subcontractor to the field owner, the City of Long Beach. Since 1932,
more than 3,400 land-based wells have been drilled in the western portion of Wilmington
oilfield. By the 1950s, that portion of the field had been completely developed under
primary recovery, and waterflooding—the injection of water into a producing formation
to "sweep" more oil to the wellbore—was started in order to increase
recovery and control subsidence. Such secondary recovery efforts often are followed by
tertiary recovery, also known as enhanced oil recovery (EOR). In Wilmington's case, the
EOR choice was a thermal approach, namely steamflooding. The introduction of heat into the
reservoir reduces a heavy crude oil’s viscosity, making it more mobile and easier to
recover.
Tidelands' project called for using advanced reservoir characterization and thermal
production technologies together with horizontal drilling to improve the efficiency of a
deep, heavy oil steamflood in Wilmington field. Steamflooding, typically an expensive
process, had been economic in the Wilmington field even when oil prices were low, because
the operators had access to a low-cost source of steam from a nearby power plant. However,
inexpensive steam became unavailable when the power plant shut down. Future expansion of
thermal recovery would require improving the efficiency and economics of heavy oil
recovery apart from the steam source.
As part of the project, Tidelands developed:
An advanced computer model to simulate the Wilmington
reservoir, which it used to optimize steam, hot water, and water injection without causing
surface subsidence—a perennial problem in the field;
New horizontal well-based steamflooding , designed with the
aid of new three-dimensional (3-D) computer models;
A novel alkaline-steam well completion technique that
controls excessive production of sand in the wellbore, cutting capital costs by 25
percent;
A new, commercial technology to scrub out deadly hydrogen
sulfide gases created in the steamflood at a 50 percent cost reduction; and
A new steam generator that can burn a variety of
low-quality waste gases created by the thermal EOR operations.
Tidelands attributes its success to both this project, and
technologies transferred from earlier DOE research. The company said it expects some of
its innovations to spread to other operators in the Los Angeles Basin, one of the Nation’s
most prolific—yet high-cost and environmentally sensitive—producing areas.
NETL project manager Jim Barnes noted that two companies are now marketing
DOE-supported technologies as a result of the project: Dynamic Graphics, Inc. (DGI),
Alameda, CA, and Geomechanics International, Inc. (GMI), Houston.
"DGI significantly expanded after they learned in the DOE project the effectiveness
of 3-D modeling in describing a complex reservoir and oilfield such as Wilmington,"
Barnes said. "Since then, they have become a 3-D modeling provider of choice to
small- and mid-size California independent operators who have seen the value of this
technology for complex reservoirs."
"Tidelands teamed with Stanford and the University of Southern California during many
of their investigative efforts," Barnes added. "GMI was started by Stanford
researchers, who developed novel well logs calibrated to accurately measure porosity and
oil saturation through sound-wave technology."
The project, entering its final phase, started up in 1995 and is slated to end early in
2007.
DOE funding is expected to account for 40 percent of the project’s estimated total
cost of more than $20 million. |
