Pumping Up Shale Pumping Tech
The well-known song about the city of New York proudly proclaims that if you can make it there, you can make it anywhere. The same concept might also apply to artificial lift technology used in the Bakken shale formation of western North Dakota. If it works there, it can also be deployed successfully in the Permian, Eagle Ford and other shale plays around the U.S.
The Bakken is known for its extreme weather conditions. Summer temperatures can soar above 100 degrees Fahrenheit and plunge to -30F in the winter. The geology ranges from sandy, silty soils on high elevations to bog-like clays in low elevations. The remoteness of many wells makes maintenance and logistics a major challenge. Well depths below 10,000 feet, multiwell pads and the corrosive nature of the fluids and frack sand also present difficulties in the Bakken.
Among the most recognized names in the artificial lift systems business operating in this region are two Texas-based companies—Weatherford Corp. and Lufkin Industries Inc. Their names are a common sight on the pumps dotting the landscape of the plains, hills and valleys throughout the Williston Basin. Years of experience operating in the basin have spawned innovations and technology modifications to cope with a multitude of challenges created by the climate, geology and remoteness.
GE’s Gen2 Solutions
GE Oil & Gas acquired Lufkin in 2013 to add artificial lift systems to its energy industry portfolio. John Mart, business operations leader for coproduction solutions, came to Lufkin from the energy generation side of GE where he worked with gas turbines. He sees the advantages of calling upon the considerable resources of GE.
For example, in the Bakken and the Permian, a common concern among operators is the variety of impurities from frack sand and flow-back that scratches and erodes the metal at the top of the pumping unit, resulting in a reduced production rate. Mart says GE provided an off-the-shelf solution.
“We’ve been able to take this really tough Dura Plus coating—it’s the same stuff that comes from our aviation business and is used on our electric submersible pumps—and we’re able to bring that to our sucker rod pumps downhole as well,” Mart explains.
Lufkin works with its oil and gas customers to identify problems, then filters them back through GE’s engineering organization for potential solutions.
“When you see a problem, you get enough people to get the sparks going to bring that creativity and those on-the-shelf technology solutions to bear on whatever problem the industry’s having,” he says.
According to Mart, Bakken operating conditions were specifically considered in designing a new rod lift system called the Lufkin Pumping Unit Gen2 technology recently released to the market.
“We brought the full weight of our global research and development team to redesign and almost reimagine this product,” he says. “We started with problems we heard in the field. Some of our key customers listed safety as a top priority. Anything we can do to protect the crews and reduce lost-time events, we knew customers were interested in.”
One improvement enables the use of a torque wrench to precisely tighten nuts rather than what Mart calls the archaic and less safe method of using a hammer wrench. Reliability has been improved with a redesigned, heavy duty gearbox to deal with well depths in the Bakken and the wear and tear it creates.
“It’s really a beefier product that can handle the load that you’re going to see up here,” Mart says. “A nice benefit of this is that when you scale up some of the pieces that handle the critical loads and the safety factors—from an engineering standpoint—those all get improved across the system.”
The new pump weighs about 10,000 pounds less than previous artificial lifts, reducing logistics costs. To minimize sagging problems in the Bakken, loading has been optimized to lower the weight on the front near the wellhead.
“You can use a smaller concrete pad and it’s going to perform better in what can be soggy conditions,” Mart notes.
Another industry trend Lufkin is addressing is a move away from simple controllers—essentially an on/off switch on a timer.
“Folks are looking for a more connected oilfield,” Mart explains. “In response to this we’re releasing the Lufkin Well Manager 2.0 rod pump controller. It’s a brand new controller that actually uses the same internals as the GE platform that controls gas turbines and wind turbines. It’s a consistent control platform with totally rewritten software. We’re able to do things to optimize around the way the pump unit works.”
Mart says Lufkin redesigned its new pumps as a complete system.
“It’s not just the pumping unit topside,” he explains. “It’s the controller, the pumping unit and then the downhole pump as well. That’s really what you need to make this thing work.”
Weatherford’s Advanced Options
Weatherford develops artificial lift products and production optimization capabilities by applying its specific technology, understanding and expertise, not only to help operators develop new oil and gas resources, but also to assist them in maximizing recovery from producing reservoirs.
Jordan Binstock, Weatherford’s U.S. product line manager for sucker rods and rod pumps, says the company’s approach centers on evolving artificial lift technology—whether it’s rod lifts, jet pumps or gas lifts—to meet the unique challenges of the Bakken and to help operators solve problems.
“A lot of what we’ve focused on is identifying the right application for the right type of pumping unit, and increasing the efficiency and the uptime of the unit itself by optimizing routine maintenance schedules, any repairs, any oil changes—anything like that to where we can keep that pumping unit running at its highest efficiency for those operators to reduce their costs,” he says.
Over the past six or seven years, Binstock says Weatherford’s Maximizer II has become the artificial lift system of choice because of a phase-crank geometry that provides more rotation on the upstroke and more efficient fluid movement. Another change he’s seen in the Bakken is the result of advanced well completion techniques. Because of increases in initial production, the installation of rod pumps, which once occurred in the first three to six months of a well’s life, now occur in six to 24 months.
James Wagener, Weatherford’s U.S. artificial lifts sales manager, says automation has been one of the largest areas of advancement for artificial lift equipment—an area in which the company is heavily involved with its Field Office software suite.
“The advantage of automation isn’t in the reduction of workforce, but the redirection of workflow,” he notes. “If you have a pumper that has a route with 60 wells on it, you don’t want him to get to the problem well at 3:30 on Friday afternoon. You’d like to be able to see in from your office which wells have warnings and which ones have flags that you need to check out first. You get those problem wells taken care of to increase your up time.”
Weatherford is currently in the pilot phase of a remote terminal unit (RTU) called the WellPilot ONE, which can monitor and control multiple wells using different lift types.
“We’re extremely excited because this is going to drastically reduce the cost to the operator,” Wagener says. “You can be on three forms of lift before you get to your final form of lift on a Bakken well. Instead of having to buy three different controllers and three different RTUs, you can by one controller—the WellPilot ONE system—and just change out the licenses within that same controller.”
Binstock says Weatherford’s system of installing artificial lift systems in the permafrost of Canada was imported to cope with the Bakken’s difficult geology. Ten to 15 steel pipes are driven into the ground until they begin to grip the soil and reach a precise load-bearing capacity. The pipes are cut off level and a concrete or steel pad is placed on top of them.
“No matter what the ground does—frost heave, load changes or anything—our pumping unit is going to maintain a 100 percent alignment throughout the life of the well,” Binstock says. “That has saved operators a lot of money because previously you would have to go in and redo that gravel pad and take down and rebuild the pumping unit every time it began to settle into the ground.”
When Weatherford introduced this system, it installed two or three a month. Now Binstock says the company is doing much more.
The operating conditions in the Bakken that begin with climate extremes on the surface and extend to the geologic conditions two miles underground have provided Lufkin and Weatherford with a wealth of knowledge and experience that they can apply to artificial lift systems in other shale plays around the U.S.
Author: Patrick C. Miller
Staff Writer, North American Shale magazine
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