How one Texas contractor approaches CO2.

When carbon dioxide (CO2) was found in New Mexico’s northeast corner, the market for the gas was uncertain. Today, CO2 is becoming a more sought-after product because of its use in everything from refrigerated food shipments to manufacturing to enhanced oil recovery (EOR). Reliant Exploration & Production, a division of Reliant Holdings Ltd. out of Midland, Texas, is one of the companies developing the Bravo Dome formation near Bueyeros. Reliant’s new Atlas Copco RD20 is an ideal drill rig for the formation, offering mobility and performance to reach the gas formation.

Breaking from his family’s business in the mid-1970s, Freddie Vanderburg, an animal science graduate from Oklahoma State Univeristy, went into cattle ranching. Vanderburg is the grandson of the late J.O. Vance, known in west Texas as a conventional oil rig manufacturer (OIME) in the 20th century.

When the technology of using CO2 for EOR became better defined, Vanderburg followed his roots, and got back into the petroleum business. Although he still runs cattle, Vanderburg likes the possibilities of CO2. “It can be dry out here with a drought year about one in every seven years.”

Some Background

As early as the 1940s, CO2 was found here in wells as shallow as 600 feet to 800 feet. Today, the Bravo Dome gas is found below that at depths between 1,900 feet and 2,950 feet from surface in the Tubb Sandstone formation. Vanderburg says the formation is about 80 feet thick. The gas is trapped in the formation by a salt seal 30 feet to 40 feet thick. He reports that experts attribute the gas to previous volcanic activity, and the Bravo Dome may be a regenerating field, at least to some extent.

Reliant’s leases are in the center of the formation where the gas is at depths around 2,300 feet below surface.

Reliant Holdings operates many businesses, with its petroleum transfer business operating under the name FloCO2. This business supplies CO2 to the oil and gas industry for EOR, including well stimulation and hydrofracturing, as well as pressure-control treatment.

To get the gas to market, a pipeline runs from multiple locations in the west, including the Bravo Dome, to the Permian Basin CO2 hub in Denver City north of Odessa. Today, the oil fields of west Texas are using CO2 to boost production because the price of crude is high, and maximizing the recovery pays off.

Vanderburg also promotes the use of CO2 for hydrofracturing enhancement. “For opening up a well, CO2 offers many benefits,” he says. The best new opportunity is the reduced amount of water necessary. “With CO2, 70-percent less water is used vs. a conventional frack.” He also mentions that no swabbing unit is needed, and the caustic nature of CO2 assists in some formations as an acid contribution etching the formation that eliminates the need for additional acids. Also, it’s cleaner because it reduces the possibility of some swelling of certain clays in producing formations. This and the fact there is less wastewater to dispose of mean there is a reduction of contamination risk and a cost savings.

Door of Discovery

Vanderburg asserts, “The secrets of nature are discovered once in a while, and CO2 has opened a door of discovery.” He adds that research has found CO2 to be important in the development of fuels. For example, off-shore oil is the result of decayed biomass, specifically algae. Because algae eat CO2, scientists have taken this knowledge to make synthetic oil from algae.

Agriculture also is benefiting from CO2. Scientists have found plants grow three times to four times faster in a controlled environment such as a greenhouse when injecting CO2. This is only the beginning.

Rig Strategy

Vanderburg bought his RD20 as a low-hour used rig in good condition, but having a common rig with available parts is an added benefit. Atlas Copco salesman Derek Anderson says it best, “The oil patch is a tough place, and occasionally things break.”

Vanderburg had been looking for a hardy rig. “You can’t just get parts down the street out here, so I needed a good package,” he comments.

“We purchased the rig with 7,700 hours in good shape, but it needed some work on the table area and main valve, otherwise that’s it.” They took just over six months rigging up the necessary equipment and adding catwalks for safer access to the compressor trailer and dog house.

“I like the safety factor with this rig,” notes Vanderburg, comparing the RD20 to conventional drills used in the region. “We don’t have people slinging chains or climbing up the derrick.”

The rig also has been a quick learn for the crew. Driller Josh Wheeler III says getting up to speed was “no more than grabbing the handles and watching the gauges – 8,000 pounds on a conventional string is the same as 8,000 pounds of pull-down on an RD20.” He also compared the RD20’s functionality to an automatic driller added to a conventional rig.

The Drilling Process

The rig has been set up to run on both mud and air. The company wanted it to be versatile for the formation, having the speed of air and down-the-hole hammer drilling as well as the control that comes from underbalanced mud drilling, although CO2 is not combustible.

To start off the well, the crew began drilling with a 12-inch hammer and a 17-inch button bit. “We ran into heavy water at 15 feet with a sandstone bottom at 40 feet that was trapping the fresh water. We were seeing 100 gallons per minute,” explains Venderburg.

Conductor pipe is set at 40 feet on this project. The surface casing is set to 700 feet, and then the hole is drilled to depth. The production hole is drilled at a 77⁄8-inch diameter.

Casing the well is a bit different than normal because of the caustic nature of a CO2 well. “We use 5-inch fiberglass casing cemented to 2,000 feet, with steel at the bottom 200 feet to 300 feet. Steel alone would rust out in three years,” says Vanderburg.

Ultimately Reliant will drill an estimated 150 wells, with one well per 160-acre quarter section of land. Vanderburg says the demand for CO2 is increasing because of its many uses, especially EOR. He emphasizes: “We are excited about the future and our RD20.”