Buried treasure

Rio Vista resource lies underground

By Jason Massad/Staff Writer
The Birds Landing Dehy Station, a high-pressure natural gas well, is located off Birds Landing Road west of Rio Vista. (Rick Roach/The Reporter)
Product profile
• Before processing, natural gas typically contains varying amounts of methane, ethane, propane, butane, carbon dioxide, oxygen, nitrogen and hydrogen sulphide.
• The natural gas that is sent into homes is almost pure methane.
• Natural gas is used to generate electricity at power plants, for heating both water and space in residential and commercial buildings, and for cooking. Some air-conditioners also run on natural gas.
• There are 130,000 natural gas vehicles in the United States and up to 5 million around the world.
• The Chinese first harnessed natural gas in about 500 B.C. They made crude pipelines out of bamboo and piped the gas to the sea, where they made the water drinkable by boiling out the salt.
• Great Britain first commercialized natural gas around 1785, using it to light home and street lamps.
• Natural gas is colorless, shapeless and odorless.
• The chemical mercaptan, which has a distinctive, "rotten egg" or "rotten cabbage" smell, has been added to natural gas since 1937, after an undetected buildup of natural gas led to an explosion at a school in New London, Texas, killing more than 300 students, teachers and parents.
• Natural Gas Supply Organization: www.naturalgas.org
• Natural gas posed a mystery to the ancients. Gas seeping from the ground would be ignited, usually by lightning, creating "eternal flames" that could not be explained. A temple built atop one such flame on Mount Parnassus in Greece housed the Oracle of Delphi. Similar fiery springs became part of the religious traditions in India and Persia.

Underneath the farmland around Rio Vista exists one of the state's largest natural gas fields.

Since its discovery in 1936, more than 3.3 trillion cubic feet of gas has been extracted from the fields beneath Rio Vista, according to state statistics.

Rosetta Resources Inc., a Texas-based oil and gas firm, now controls most, if not all, of the natural gas leases in the area, which is spread across 90 tracts, said Mike Hickey, general counsel for the company.

"It's one of our key producing areas," he said.

According to the company's Web site, www.rosettare

sources.com, the Rio Vista Gas Field is the largest onshore natural gas field in California and one of the 15 largest fields in the United States.

"From Jan. 1, 2005, to Sept. 30, 2005, our average net daily production in the Sacramento Basin was approximately 34 million cubic feet per day from 167 producing wells," according to a report posted at the Web site. "We currently produce from over 16 different zones at depths ranging from 2,500 feet to 9,600 feet in the field. As of Sept. 30, 2005, we owned approximately 62,375 net acres in the Rio Vista Field and surrounding Sacramento Basin areas."

Normally, once the natural gas is extracted, it is pressurized and piped to a processing plant where it is purified by removing water and other naturally occurring liquids. Those liquids, such as propane or butane, are valuable in their own right and sold accordingly. "Nothing goes to waste, that's for sure," said Hickey.

The natural gas, meanwhile, is blended to ensure it has the proper Btu level before it is piped to customers such as Calpine, an independent operator of power plants, or even PG&E.

The gas extracted from Rio Vista, usually pure enough to send directly to customers, "is used in California, either to generate power or sent to the liquid distributors," said Hickey.

Natural gas prices, Hickey said, have not risen along the lines of oil. But prices still dictate that companies explore areas such as Rio Vista, which have established natural gas fields.

Natural gas production at Rio Vista's field has diminished greatly in the seven decades since natural gas was discovered there, but now it may have another use.

A Lodi-based company is proposing to store natural gas in an empty natural gas well in the Rio Vista area.

Unlike electricity, natural gas can be stored and then used at times of peak power demand, such as the summertime. Energy companies create reserves to be sold on the regional energy market.

A pilot project to store carbon dioxide, considered a greenhouse gas that can lead to global warming, is also moving forward near Rio Vista. A coalition of western states are studying whether it can trap the emissions from industry and then store them underground. Rosetta Resources Inc. will oversee the drilling of the pilot well, Hickey said.

The Texas company, meanwhile, operates all over Northern California. In addition to Rio Vista, the company also has leases and assets in Sacramento, Yolo and Sutter counties.

Rosetta Resources replaced Calpine Corp. in 2005, after it purchased all of Calpine's oil and natural gas interests.

Send comments to citydesk@thereporter.com.