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.