Back then, such a flow rate of low-gravity oil in a wildcat didn't exactly set the heart racing. It even took state authorities 54 months to declare the result a new field discovery.

Little did they know it would evolve into one of the four largest oilfields in the United States and one of the most impressive success stories of urban oilfield development.

Wilmington oilfield, the biggest in the Los Angeles Basin, extends southeast to northwest through the basin, from the middle of San Pedro Bay through the City of Long Beach and east of the Palos Verdes Peninsula. (Click here for the Wilmington field location ma.)

The field's original-oil-in-place volume is estimated at 9 billion bbl. It has produced over 2.6 billion bbl of oil to date, and remaining proved reserves are pegged at about 340 million bbl. Wilmington produced about 14-15 million bbl/year from more than 1,200 wells in 2004-2005 and currently produces about 40,000 bbl/day of oil, 10 million cubic feet per day of natural gas, and about 35 million bbl/month of water at a 95 percent watercut.

Wilmington history
Even more remarkable than its current robust production numbers is the aging field's unique history. Wilmington is a broad, gently sloping anticline about 13 miles long by 3 miles wide, much of it underlying Long Beach Harbor, one of the world's largest commercial shipping ports. (Click here to see photo of Long Beach Harbor today.) More than 1,000 wells were drilled in its initial development during 1939-42 by a consortium of companies called Long Beach Oil Development Company, the city's first oil contractor. (Click here to see a photo of Terminal Island drilling-production operations in the 1940s.)

The rapid rate of oil extraction contributed to a catastrophic subsidence problem. First noticed in 1941, with a drop of more than a foot, it wasn't clear what was causing the subsidence. By 1958, ground level had dropped by 27 ft in the field's center, and a large area of the city had sunk below sea level, causing damage to industrial and port facilities and requiring the installation of levees and breakwaters—all at a cost of more than $100 million. (Click here to see a photo of subsidence at Long Beach.)

A $30 million program of water injection got underway in 1953, in part to combat the subsidence but also to introduce secondary recovery. The waterflooding succeeded at both levels. Subsidence was halted by 1962—and even rebounded, recovering as much as 2 ft of ground level—and oil production increased. The billionth barrel of oil was produced at Wilmington by 1964. What could have been just a costly disaster for one of the Nation's most important ports and a black eye for the oil industry was corrected with a solution that not only fixed the city's problem but also yielded hundreds of millions of dollars in royalties to the city. It also helped overcome drilling restrictions instituted as a result of subsidence concerns, allowing further expansion of the field offshore.

Expansion of Wilmington development proceeded in 1965 when the City of Long Beach's oil contractor, the THUMS (Texaco, Humble, Union, Mobil, and Shell) consortium, won approval to drill the offshore extension of the field from four artificial islands installed in Long Beach Harbor. (Click here to see a photo of Long Beach Harbor and the oil islands.) The 10-acre oil islands-Grissom, Chaffee, White, and Freeman-were named after four astronauts who lost their lives in the early days of the U.S. space program. (Click here to see a photo of Grissom Island.) The drilling rig masts on the islands were cleverly camouflaged and landscaped to look like residential buildings in a resort-like setting. (Click here to see a photo of a Long Beach oil island.) To this day, the City of Long Beach receives inquiries from real estate buyers interested in "those high-rise condos in the harbor."

Wilmington field development has received worldwide recognition for its success in developing a world-class oilfield in an urban setting without interfering with the port's massive shipping operations, disrupting the harbor's recreational resources, or detracting from the shoreline's natural beauty. And all of this occurred in a state widely regarded by industry as having the world's most stringent environmental regulatory regime. (Click here to see a photo of Grissom Island.)

Overall, more than 6,150 wells have been drilled in Wilmington field in the roughly 70 years it has been producing. Oil is produced from five major sand intervals at depths ranging from 2,000 ft to 11,000 ft. The entire field is now under waterflood, and steamflooding has been implemented in some areas. This not only boosts oil recovery, but the continued water injection also halts underground compaction and surface subsidence.

The eastern part of Wilmington, also known as the Long Beach Unit, was developed with more than 1,000 wells drilled during 1965-1982 and underwent infill drilling with 460 more wells during 1982-86. Occidental Petroleum Corp. acquired THUMS in 2000; its wholly owned subsidiary Occidental Long Beach Inc. is the field contractor for the Long Beach Unit today. (Click here to see a map of Long Beach oil operating areas.)

A small, Long Beach-based independent, Tidelands Oil Production Company, is the field contractor for the western portion of Wilmington field.

By 1991, declining production in the onshore, western portion of the field had led the City of Long Beach to start looking into abandoning that area of the field because of its perceived limited remaining potential. After receiving two DOE projects awarded in 1995, Tidelands has been able to maintain the western area properties despite a big well and surface facility abandonment program necessitated in part by earlier subsidence. At the same time, port expansion work enabled Tidelands to gain assistance from the Port Authority in replacing infrastructure.

The next step was to carry through an ambitious effort, funded in part by DOE and managed by NETL, to boost production and increase ultimate recovery of oil in Wilmington's western area in a cost-effective and environmentally sound manner. (Click here to see a aerial photo of Wilmington production areas.)

The project
Tidelands' project is expected to add ultimately 13 million bbl of incremental oil production in a small portion of Wilmington field. (A detailed project summary is provided here for a brief update of the project.)

If the new technology and innovative techniques developed under the project are applied field-wide, it could result in boosting Wilmington's ultimate oil recovery by 525 million barrels of oil—an increase of over 150 percent from the latest estimate of remaining oil reserves in the field. Achieving that jump in a single oilfield equates to a 2.5% increase in total U.S. proved oil reserves. An aggressive effort to transfer this technology could boost reserves in similar fields in California by 1.4 billion barrels of oil.

The project originally had envisioned an increase in production in that targeted portion of Wilmington field from 8,000 barrels per day of heavy oil in 2005 to 9,600 barrels per day in 2010. A drilling program based on lessons learned from the DOE research already has hiked oil production in the target area from 6,100 barrels per day in 2002 to an average 8,793 barrels per day in November 2005—a level researchers didn't expect to achieve before late 2007. Expectations now are that the project will reach almost 10,000 barrels per day by the end of 2006.

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. The main producing horizon at Wilmington is a slope-and-basin clastic (SBC) reservoir. Steamflooding had been economic in 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 isn't expected to be available to Wilmington operations in years to come, as the power plant has shut down. Future expansion of thermal enhanced oil recovery (EOR) to other parts of Wilmington field thus depends on improving the efficiency and economics of heavy oil recovery apart from the steam source.

The DOE-funded project addressed several producibility problems in two large portions of Tidelands' operating area that are common to SBC reservoirs. Difficulties with oil recovery arose frequently because the targeted Wilmington formations are relatively deep, high-pressured, and heterogeneous compared with those found in thermal EOR projects elsewhere in the state.

Among many other innovations, Tidelands developed:

• an advanced computer model to simulate the Wilmington reservoir, which it used to optimize steam, hot water, and water injection with oil production efforts without causing surface subsidence—a perennial problem in the field;
  
  
• a series of operational changes based on the new reservoir model to improve heat efficiency, reduce costs, and expand steamflood operations;
  
  
• new horizontal steamflood pilots, with the aid of new 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%;
  
  
• new ways to reduce the formation of scale minerals in the producing wellbores, further trimming well costs;
  
  
• a new, commercial technology to scrub out deadly hydrogen sulfide gases created in the steamflood at a 50% cost reduction; and
  
  
• a new steam generator that can burn a variety of low-quality waste gases created by the thermal EOR operations.

As a result of these innovations, Tidelands in 2003-2005 enjoyed the most successful round of drilling in the Wilmington onshore field area in 20 years, boosting production by 25-45 percent just since 2003. The company attributes these successes to technologies transferred from earlier DOE reservoir-class research. Several of these technologies have since been commercialized by service companies, been adopted or further researched by other oil companies, or used by Tidelands in other operating areas. The company 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.

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% of the project's estimated total cost of more than $20 million.

In addition, NETL project manager Jim Barnes, based in Tulsa, OK, noted that two significant companies have started up as a result of the project: Dynamic Graphics, Inc. (DGI), Alameda, CA, and Geomechanics International, Inc. (GMI), Houston.

“DGI started expansion in the mid-1990s after they realized the effectiveness of 3-D modeling in describing a complex reservoir and oilfield such as Wilmington; 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,” Barnes said. “Tidelands teamed with Stanford and the University of Southern California during many of their investigative efforts; GMI was a company during this time that came out of Stanford researchers, who developed dipole acoustic/sonic [well] logs calibrated to accurately measure porosity and oil saturation through acoustic wave technology.”

Tidelands' Wilmington project is one of a number that DOE supported in its Reservoir Class Oil Field Recovery program. Begun in 1991, the program targeted geologic classes of U.S. oilfields that were on the verge of being prematurely abandoned. With federal matching funds allowing higher-risk technologies to be tried, many operators have been able to keep oil flowing from these fields long after conventional wisdom labeled them "depleted.”

Much of Wilmington's oil is viscous, low gravity, and difficult to recover by primary means. With proper reservoir description, improved well completions, directional drilling, and the proper application of steam, the recovery of this difficult-to-recover oil has become an economic reality.

There are many other large, mature SBC reservoirs in the United States, notably elsewhere in California and in the Gulf of Mexico. With the new technologies and innovative techniques emerging from Tidelands' ambitious project at Wilmington, other venerable U.S. oilfield giants can win a new lease on life as well.

It certainly has paid off for the City of Long Beach and Tidelands at Wilmington, where oil production now is expected to continue for at least another 20 years.

This CD contains a partial record of the Tidelands DOE project, DE-FC22-95BC14939, Increasing Heavy Oil Reserves in the Wilmington Oil Field Through Advanced Reservoir Characterization and Thermal Production Technologies, in the form of:

• An annual report covering the reporting period April 1, 1996, to March 31, 1997.

• The latest annual report, covering the reporting period April 1, 2005, to March 31, 2006.

• A paper detailing the novel well completion technique developed in the Wilmington project for controlling unconsolidated sand formations by using steam.

• A paper analyzing stratigraphic equivalents to Wilmington field elsewhere in the Los Angeles Basin, with an eye to transferring technology from the project to other operators working in the basin.

• A paper assessing the project's use of detailed reservoir characterization, 3-D modeling, and horizontal drilling to boost oil recovery in Wilmington field.

• An image gallery depicting scenes old and new from the Wilmington/Long Beach Harbor area, as well as recent project-related photos. (Click here to view the Image Gallery.)

For further information, please contact Jim Barnes (NETL, jim.barnes@netl.doe.gov, 918-699-2076) or Scott Hara (Tidelands, scott.hara@tidelandsoil.com, 562-436-9918).