Your account already exists. Please login first to continue managing your settings.
A polymer, which replaces guar in fracing fluid, has been utilized by Halliburton in Magnum Hunter’s wells in the Eagle Ford, resulting in higher flow back and improved production.
Guar production in India depends on the weather. Farmers need strong monsoon rains followed by an arid period to produce bumper crops of one of the key materials in hydraulic fracturing fluids. Sometimes the farmers choose to grow cotton rather than guar.
With the booming demand for frac fluids in North America, the pressure on guar supply led to higher prices for the product. Service companies are hoping for the weather to cooperate for a bumper crop.
However, Halliburton took on the challenge of finding a guar substitute that would address two problems – residue from the guar bean and supply uncertainty around guar. The company went to the marketplace and found a polymer that is effective and leaves no residue. A product called PermStim has been used by 23 customers in about 125 wells and almost 1,700 frac stages in the Denver-Julesberg, Williston, Green River, and Eagle Ford basins.
“We had to have a polymer with performance comparable to the guar systems we’ve worked on for decades in that: it had to be versatile and handle salts; it had to rapidly hydrate so the polymer could be incorporated into the operations with minimal interruptions; and we had to be able to control the breaker,” said Ward Dempsey, product champion, production enhancement, Halliburton, during a press conference at the SPE Annual Technology Conference and Exhibition in San Antonio Oct. 9.
“We also needed good proppant transport because we need to place a lot of sand in those fracture networks. We needed low fluid leak-off to get the frac width. And, we needed a good source of supply,” he continued. “We have an excellent supply agreement for the polymer, which means we are not subject to environmental or geopolitical interference.”
There are two forms of residue that exist with guar that can be problematic by impacting conductivity in the proppant pack or regain permeability in the matrix, he explained. One is the insoluble materials that are part of the guar bean itself.
“Guar is graded out. Halliburton buys the highest grade – WG-39 – but we still know it has some potential damaging residue in it,” Dempsey said.
A second potential damage mechanism deals with breaking the guar itself. Sugar molecules are attached to a mannose backbone. If a breaker system is being used that is not aggressive enough when the sugar molecules come off, the mannose backbone becomes insoluble.
Without the residue, frac clean-up is more rapid with minimal damage to the proppant pack. The polymer mimics the behavior of the guar systems. It is efficient at proppant transport, and given the low fluid leak-off, the formation gets good frac generation, he added.
But, the proof is in the results. Halliburton began a controlled introduction of PermStim, starting in the Rocky Mountain region. The company started with 29 vertical wells in the DJ basin, followed by 40 horizontal wells in the Williston basin, and 20 wells in the Green River basin.
In September, the product was introduced into the Eagle Ford under the auspices of Magnum Hunter Resources Corp., which is one of the more proficient producers in the play.
“Overall, we have areas of interest in the Bakken, Eagle Ford, Marcellus, and Utica,” said H.C. “Kip” Ferguson III, executive vice president, exploration, Magnum Hunter. “We started looking at how we can improve our assets in North America. We have more than 4,000 wells to drill in our asset inventory.”
The company is always evaluating new technology that can impact its wells, and it has worked with Halliburton successfully in the past.
Colton Thomas, account manager, Halliburton, works with Magnum Hunter. He pointed out that the operator had used a cookie-cutter approach to its Eagle Ford wells.
Ferguson said, “One of the things about our area in the Eagle Ford is that it is very predictable. We generally know where our fluid is going to be, how many stages we have, how long our laterals are going to be, and what the IPs are going to be with the current guar gel systems.
“In adding a PermStim system, we are able to document and figure out how much added advantage we get with clean fluid and less residual fluid,” he continued. “Bottom line, we added about a 20% increase over our average IP for our operated wells, which is amazing. Today, we make about 7,000 b/d to 8,000 b/d. If you add just 20% to that, it is a significant enhancement of our income, internal rate of return, and the estimated ultimate recoveries for our wells.”
He pointed out that Magnum Hunter is less focused on IPs and more on productivity of the wells longer term. “It’s about what these wells will become in the next five to 10 years and not just about what you get in the first 60 days or 90 days. We want to know how these incredible reserves in formations with very little natural permeability are going to be affected by the fluid we pump.”
Thomas added, “We ran it [in September] in the first well. Once Magnum Hunter drilled out the plugs and started flowing the well, the company showed a 20% increase in the 24-hour IP over its average for these assets. What is the production going to be in six years? We don’t know yet, but with a fluid that has less residue and 94% regain permeability, it has got to enhance that production.”
In answering a question from Hart E&P, Halliburton stated that at today’s guar prices, its new product is lower cost than its guar-based systems. The lower cost is one reason for the increase in interest for the system. With variable guar prices, Halliburton will continue to evaluate the breakeven for the polymer-based system.
Contact the author, Scott Weeden, at email@example.com.