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Downhole blending process a success RealtimeZone completes three of its patented downhole-blended fracture stimulation tests, gears up for fourth in DOE-funded project Patricia Jones Petroleum News Contributing Writer
RealtimeZone, a Roswell, N.M.-based company specializing in developing real-time stimulation processes for improving oil and gas production, is preparing for its fourth test of a patented, cost-reducing fracture stimulation technique.
With partial funding from the U.S. Department of Energy, RealtimeZone will use its simple method of blending stimulant fracture fluids downhole, rather than on the surface, at a 5,000-foot oil well in Eddy County, N.M.
The fracture stimulation test is scheduled within the next three weeks, said George Scott, RealtimeZone president, in a telephone interview with Petroleum News on Sept. 2.
Three other wells in New Mexico have been fracture stimulated using the downhole mixing technique, part of a three-year research project backed by $1.2 million from DOE’s National Energy Technology Laboratory and $549,000 from RealtimeZone.
“The process (Scott) has developed, we’ve demonstrated that it works … and it saves money,” said Gary Covatch, NETL’s project manager. “On the first job, it actually was about 50 percent of the cost that a normal fracture job would cost.”
Cost savings come from a reduction in horsepower needed for pumping, coupled with lower pressures necessary for the downhole mixing, Scott said.
His downhole mixing technique, patented by RealtimeZone and co-authored by Covatch, also provides quicker reaction time in altering fluid mixtures during a fracture stimulation, increasing the chances of a successful penetration.
The delay between changing the stimulant mixture and the effect on the rock strata is less than one minute when using the downhole mixing technique, compared to 30 to 60 minutes using conventional surface mixing, according to DOE’s project summary.
Finally, Scott’s method is safer, he said, due to a decrease in the surface treating pressures. For example, the first well tested with the process, a 12,300-foot natural gas well, was injected with surface treating pressures averaging 5,000 psig.
“Normally, the typical pressure would be 10,000,” Scott said.
First well a success That natural gas well located near Carlsbad, N.M., was field tested in September 2000 with the RealtimeZone downhole fracture stimulation process. Previous to the test, production had dropped off and the natural gas well was scheduled to be plugged and abandoned.
The producer “elected not to spend the money” on the well, so Scott’s company purchased it for the test, he said. “You end up getting someone’s dog well, because they don’t want to risk this on something that is more viable.”
RealtimeZone pumped liquid carbon dioxide down the well in its tubing and fracture stimulation fluids of methanol-gelled water and proppant, down the casing, Scott said. About 50 to 100 feet above the perforation site are where the fluids are mixed.
RealtimeZone’s tracer monitoring and logging system determine the amount of fracturing in rock strata in real time, allowing the mixture to be altered as needed, Scott said. Gamma-emitting tracers showed successful fracturing after the treatment.
“We showed that we could put the treatment where we wanted to, when we wanted to,” he said.
After the successful fracture stimulation, the well produced up to 300,000 cubic feet a day of natural gas. “It is still producing, although it has dropped off,” Scott said. “It produced pretty well for the first couple years, now it’s down to marginal levels.” Works on oil wells The RealtimeZone technique has also been applied to two oil wells, both roughly 5,000 feet deep, also located in New Mexico. The first was successfully fractured in 2001, boosting production from three to about 25 barrels per day.
The second well, fractured in March 2003, also boosted production up to 25 bpd, but has since leveled off at the 10 to 12 bpd level, Scott said. “The production part is bonus,” he said. “The main focus is to prove the process.”
Compared to conventional fracture stimulation costs for such oil wells, the RealtimeZone process produced a “30 to 40 percent reduction in total cost treatment,” Scott said. Service company giant Halliburton has licensed the technique, and Scott said he is interested in licensing its use to other service companies.
“My perspective is, if it’s something that helps the industry, let’s get it out there,” he said. Cost savings substantial According to DOE’s project summary, the gas industry spends more than $1 billion a year on fracture stimulations. “If this technology were used on 20 percent of the stimulations performed, it could save the industry nearly $100 million per year,” the project summary stated.
However, service companies may not be eager to embrace the cost-saving technique, Covatch said, as it could decrease the amount of money earned for fracture stimulation work performed for producers.
Scott said he’s seen considerable interest in the technique. “It’s easier and cheaper for the service companies — I don’t know whether they’ll pass those savings on to their client. For my jobs, the cost have been way lower.”
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