SCIENCE DRIVES NIOBRARA SUCCESS
WPX’s Niobrara Shale natural gas discovery, which was announced in January, is a prime example of how WPX is using science and technology to its advantage. It was a complex feat requiring creative strategy, critical thinking and innovative methods.
The discovery well, which is in Garfield County in the Piceance Basin, registered an initial production rate of 16 million cubic feet per day at 7,300 pounds per square inch (psi) flowing casing pressure.
And it exceeded 1 billion cubic feet of natural gas production after its first 100 days of operation.
Over time, the Niobrara discovery in the Piceance ultimately has the potential to more than double WPX’s proved, probable and possible (3P) reserves.
This was WPX’s first leap into the Niobrara formation, which lies at a challenging depth. The team drilled the horizontal test well to a total vertical depth of 10,200 feet with a 4,600-foot horizontal lateral.
Obtaining a core sample in the pilot well, researching state records on offset operator wells, and performing tests in the offset vertical well took months of planning.
“One of the challenges from a geological standpoint was finding an area where the structural dip was gentle. We were looking for an area with just the right dip to make it easier to drill horizontally,” says Jon Cantwell, senior staff geoscientist.
The rock in the formation is made up mostly of pelletal argillaceous mudstone, which is more than 50 feet thick and comprised of organic and calcium carbonate content.
“From the core sample, we found that the zone we selected had the rock with the best reservoir properties – the ones that would ultimately produce the most natural gas,” Cantwell says.
The team had to determine the tools and equipment necessary to drill the pilot well that could handle tremendously high temperatures – which reached up to 300 degrees Fahrenheit in certain spots.
Equipment that worked fine in shallower environments could not handle the Niobrara heat. Specific mud motors and MWD (measurement while drilling) tools fitted with internal components rated for high temperatures were necessary.
We also purchased pump parts specifically designed for the heat, along with special frac heads, electronics and logging equipment, and even batteries.
Drilling operations commenced in August 2012 during which the company successfully recovered 535 feet of continuous core.
Justin Beougher, a drilling engineer based in Denver, says when the team hit an obstacle, they relied on others within WPX for their knowledge and experience, including drilling engineers from WPX’s Marcellus operations, who shared recommendations on the drilling plan.
The intermediate section of the hole was tricky. “It was a very big hole to drill to 9,000-plus feet,” Beougher says. “We had to experiment with different drill bits, directional assemblies and techniques to try and speed up the drilling for that interval – we ultimately used a 12-1/4-inch drill bit.”
“Then, we had some issues drilling the curved portion of the well, so we starting making phone calls to other experts in our basins, including contractors from our Bakken and Marcellus assets,” he says.
“They offered some valuable insight into how to make the curve successful. Thanks to the expertise and experience we have across our company, we worked it out.”
The completions process presented more unchartered conditions– the Niobrara formation is highly over-pressurized. The team conducted proppant embedment testing to determine how the fluids and equipment would handle the stress of 10,000 pounds per square inch.
Completion operations, including 17 frac stages, were completed in December 2012.
“Reality doesn’t always match theory,” says Chris Caplis, a senior petroleum engineer based in Denver. “We had to make a few adjustments on the fly fairly early on, but the remaining stages went off without a hitch.”
“To stimulate the well at the rate we wanted, it took a lot of research. We had to use high-temperature tools and equipment meant for such a high-pressure environment,” says Jason Bundick, a completions superintendent based in Parachute, Colo.
“One solution in the completions process was in proppant selection. We couldn’t go with the proppants like we typically use in shallower wells in the Piceance, so we chose ceramic sand, which is much stronger. Ceramics have higher strength, do not crush and do not flow out of the well.”
Multiple tests concluded that ceramic proppants also resulted in higher permeability and higher conductivity, so the process would better capture the end result – gas molecules.
WPX also uses ceramic proppant in its oil wells in the Bakken Shale because ceramics provide superior well performance due to increased fracture conductivity.
In 2013, WPX plans to drill four horizontal Niobrara wells, up from its original plan of two.
The drilling plan is designed to prove up adjacent acreage and test the repeatability of the play on additional acreage the company owns.
WPX already has extensive processing and takeaway capacity under contract in the Piceance. WPX also has the lease rights to approximately 180,000 net acres of the Niobrara/Mancos shale play in the basin.
The group responsible for the discovery includes WPX geoscientists, engineers, field operations, landmen and other staff outside of Colorado.
“Everybody had a positive attitude, even during times when things were not going so well,” says Chris Walsh, senior landman.
“Everyone’s feedback was taken into consideration, and everyone was willing to listen.”
The success of the Niobrara discovery illustrates how WPX’s operations process is structured – by leveraging resources across the company and sharing scientific and technological data, methods and expertise.
“From the planning and land decisions to the technical design to the final development of the well, it took a big team,” says Chad Odegard, vice president of the Piceance.
“The potential of this new resource is huge and adds to the already-fantastic WPX portfolio.”