The reason for making the antifriction agent on site is simple: only one truck is needed to transport the dry polymer, and the same amount of liquid additive requires three trucks.
Mark Van Domelen said that for Downhole Chemical Solutions (DCS), by mixing on-site as needed to reduce the number of strokes and the amount of chemicals required to produce a stable liquid, the average cost of a gallon of friction reducer can be reduced by about 30%. DCS Vice President of Technology.
"The industry is very cruel and competitive in terms of polyacrylamide pricing. We can further reduce the cost of friction reducers," using dry polymers, he said.
Polyacrylamide is often described as a key component of friction reducers. Suppliers will also add some ingredients to create a stable liquid, while other ingredients can improve performance. When DCS delivers the dried polymer to the well pad for on-site mixing, the only other ingredient is customer-supplied water.
For this private company, this is a successful strategic shift; it has grown rapidly, even during the downturn last year. Van Domelen said that DCS increased the number of mixing devices from 1 to 16, and dry polymer sales increased from 10% to 90%.
One of the company’s customers is John Blevins, the chief operating officer of Houston-based Hibernia Resources III and an early adopter. He is a paper on making friction reducers on site during fracturing (SPE 204176) The main author.
Blevin uses the terms "friction reducer" and "polymer" interchangeably. He is a rare C-level executive. He likes to manage operations on a fracturing truck for a company that usually completes one cushion at a time.
The polymer is polyacrylamide. When Blevin worked with DCS on a well, he bought it directly from one of the few chemical companies that would produce polymers according to his specifications. The price on the DCS invoice is the price per pound including polymer and service costs.
In Hibernia, a small private equity and employee-owned company, there is a strong incentive to pay close attention to details.
“When we spend a penny, that five cents will be divided among us at some point in time. If we are thrifty effectively, we will live better in the long run,” Blevins said.
The paper was published at the Unconventional Resources Technology Conference (URTeC) and contains a chart showing the staged costs. The average cost of the dry stage is 27% to 31% lower than the similar stage using fluid fracturing.
The simplicity of mixing is a plus for Blevins, and his company pays particular attention to the possible reactions of chemicals downhole.
He said: “Before we pump anything underground, we conducted a 6-month study to make sure we have the right combination of fracturing additives.” "We did research almost every well and every landing zone to ensure that the chemicals used are compatible."
Dry powder only accounts for a small part of the anti-friction agent market, but it is growing.
Those who sell dry powder blends must respond to concerns based on some early failures. Pioneers in the industry proved that simply mixing the friction reducer with water can completely destroy the project and force the fracturing to stop.
"You can't throw it into the water like a guar," Van Domelen said. Putting polyacrylamide and water together is likely to cause "polymer clumps to clog pumps and mixers."
The URTeC paper describes the powder conveying and mixing devices designed by DCS, which are built into truck trailers. The description of the DCS function shows that it is difficult to reliably provide a smooth mix.
Van Domelen said this requires a high-energy mixing process. The DCS method relies on nozzles that use the Bernoulli effect to create a vacuum, suck in powder and combine it with a specified amount of water to form a concentrated liquid. During pressure pumping, the concentrate flows into the fracturing mixer as needed.
The trailer containing the dry polymer includes a humidity control device to ensure that it does not clump. The water inlet provides real-time chemical analysis, because the composition of the water may change in ways that may impair performance.
To date, DCS has blended 35 million pounds of polymer, producing approximately 2.5 gallons of concentrated friction reducer per pound. Van Domelen said they have completed work in the Permian, Haynesville, Oklahoma, and Eagle Ford with almost no downtime.
Although the company did not report the downtime of its work, Blevins stated that during the 110-day fracturing performed by Hibernia, only 2 hours of downtime were lost due to system reasons.
Producing fluid while fracturing allows Hibernia's fracturing staff to adjust the characteristics of the anti-friction agent while pumping, even when the fracturing readings do not go as planned.
On a mat, Blevins said the performance was so poor that Hibernia stopped the work and introduced a different type of polyacrylamide powder to complete the work.
"Our waters have changed. This shows that our anti-friction agents have not produced the same anti-friction effects that have been seen in stages before," Blevins said, adding that work started as planned from there.
When mixing polymers on site, Blevins uses much less polymer per gallon to reduce friction. He said this may be because the fluid in the liquid mixture formed a residue on the hose, leaving some polymer behind. He worries about whether certain components of the liquid antifriction agent have shortcomings.
Van Domelen sees no problem with liquids, where the polymer is mixed with an emulsion made of mineral oil and water sold by DCS. He said that some liquids are suspensions—polymers are delivered in liquid form including suspending agents, surfactants, and dispersing agents. Taking into account that some of these components may cause damage to the formation, Van Domelen pointed out that the possible production loss caused by the friction reducer is much smaller than the guar gum that it has largely replaced.
Switching to dry polymers simplifies the purchase to some extent. The choices provided by DCS are based on the range of polyacrylamides provided by chemical companies, and there are many choices. There are different sizes of polymer molecules, each with its own advantages and disadvantages. Cation and anion charges affect the risk of destructive reactions. Each of these variables affects prices.
These variables are limited compared to the range of formulations provided by the additive manufacturer. These manufacturers sell customized (usually proprietary) blends that contain ingredients that are expected to improve performance.
One of the additive manufacturers is Rockwater Energy Solutions, whose vice president of technology Brian Price (Brian Price) said that the dry cost savings need to be weighed against how this affects the performance of the fractured well. "This is back to the applicability of a particular field," he said.
For the operator, the only way to measure the work in the well is to conduct field tests. Even Blevins, who likes to use powdered polymers, have not dried up completely. Hibernia has been testing a liquid antifriction agent recently. Blevins did not discuss the results, but did say that he hopes to re-use dry friction reducers later this year.
He wanted to know whether wells fracturing with mixed dry powders on site in the Permian Midland Basin might perform better than wells fracturing with liquids. So far, this is just a hunch.
"There are some production-related things out there," Blevins said, adding, "We haven't been able to analyze it yet. I think we are seeing higher production oil wells, but it is still time to draw conclusions. Too early."
SPE 204176 Dry powder delivery of friction reducers: a step change in slickwater fracturing Authors: J. Blevins, Hibernia Resources; M. Van Domelen, Z. West, J. Rall, and D. Wakefield, Downhole Chemical Solutions.
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Journal of Petroleum Technology is the flagship magazine of the Society of Petroleum Engineers, providing authoritative briefings and topics about the advancement of exploration and production technology, oil and gas industry issues, and news about SPE and its members.
ISSN: 1944-978X (online) ISSN: 0149-2136 (print)