Centura Oil Stimulates Methane Wells with Waterjet
Centura Oil Inc. of Minnetonka, Minn., is dramatically increasing oil and gas well productivity with its CenJet 90® 90º downhole waterjet cutting system.
Powered by a portable Jet Edge diesel-powered waterjet intensifier pump, the CenJet 90® uses a 55,000psi waterjet cutter to quickly pierce through the well casing and cut multiple 8' to 10' long lateral perforations up to 10" in diameter into the surrounding coalseam. This unique waterjetting process can increase a coalbed methane well's production up to 300% by expanding its area of influence by 16' to 20' in diameter at multiple depths, said Centura Oil President Michael Uthe, who noted that the process typically pays for itself within a year.
According to Uthe, the CenJet 90® has successfully stimulated coalbed methane wells more than 3,400' deep in the San Juan Basin, New Mexico. The system is capable of cutting at depths greater than 4,000'. Centura Oil's CenJet 90® waterjet system can be used to stimulate any type of cased or uncased well, including coalbed methane, natural gas and oil. It works especially well in coalbed methane wells because it can cut through the coal seam much more effectively than traditional well stimulation methods. The process typically requires less than two days of site work.
The CenJet 90® consists of a modified Jet Edge Permalign II® abrasivejet cutting head that is coupled to coiled steel tubing and lowered down the wellbore. The cutting head is oriented at 90 degrees to the well casing and is brought up to pressure at precise depths to perforate the casing and surrounding formation. The powerful abrasive waterjet, which is capable of cutting 15" titanium, cuts a single perforation in San Juan Basin coal in about 15 minutes at 55,000 psi. During operation, the tool never leaves the wellbore.
Uthe said he decided to equip the CenJet 90® with a Jet Edge intensifier pump and to use a modified version of Jet Edge's waterjet cutting head because he needed dependable equipment that could stand up to a harsh remote environment.
"If I have 3,000 feet of hose downhole, and something breaks, I stand to lose a lot of money. I bought the Jet Edge waterjet intensifier pump after meeting [then Jet Edge President] Jerry Lague and getting several referrals from people who told me that Jet Edge was the most reliable pump on the market. The Jet Edge waterjet pump has been extremely dependable and Jet Edge's support has been excellent. I know that when I need to call Jet Edge, someone will answer. Even on Saturdays, I can get through to someone on Jet Edge's 24-hour emergency cell phone."
Centura Oil's waterjet well stimulation process is far more cost effective and environmentally friendly than conventional coalbed methane well completion and rehabilitation methods, Uthe noted.
"Conventional perforation operations are typically performed using a shaped charge," he explained. "The formation can experience damage due to the violent nature of the explosive charge. The CenJet 90®, on the other hand, washes and cleans as it is cutting, eliminating near well bore damage and increasing perforation depth by as much as three times that of conventional perforations.
"Conventional well completion and rehabilitation projects also typically require costly hydraulic fracturing to keep fractures open. The hydraulic fracturing process involves pumping chemical fluids and proppants, such as sand or ceramic beads, into the formation. To date, none of the coalbed methane wells stimulated by Centura Oil's waterjetting system have needed to be fracture stimulated."
Centura Oil's waterjet well stimulation process has numerous environmental benefits. Stimulating existing wells extends their lives and increases their productivity, reducing the need for energy companies to drill new wells. Since wells stimulated by the CenJet 90® have not required hydraulic fracturing, their owners have avoided those costs and potential damage to the formation. The CenJet 90® uses only four gallons of water and one pound of garnet abrasive per minute. Garnet is a natural stone that can be disposed of in a landfill. The effluent created by the waterjet cutting process consists of coal cuttings, garnet and water. It is flushed out of the well and discharged into a lined holding pond.
Centura Oil offers its waterjet well recompletion and production enhancement services worldwide and plans to expand into new well completions. In addition to providing well stimulation service, Centura Oil also sells its CenJet 90® waterjetting systems under a licensing agreement.