Drilling advances

A headline in a March 14 posting in the EagleFordShale.com platform reinforced what folks who regularly travel across the beaten-down arteries crisscrossing South Texas know all too well: “Eagle Ford County Roads a Mess.”

To be sure, it is far from a secret that roads more suited to accommodating cotton haulers were shown to be ill-designed as passageways for what were once endless streams of frac spreads and the like. Now, left in the wake of the once-humming Eagle Ford shale play is a collection of potholes, ripples and torn shoulders disguised as roadways, which Texas highway officials estimate will cost hundreds of millions of dollars to fully repair.

If operator BHP Billiton and oilfield waste management company Polk Operating, LLC, have their way, however, at least one source of the problem could help provide a solution. Their joint effort to transform oil-based mud (OBM) cuttings into a usable product reached a milestone in June, with Polk’s donation of recycled drilling waste as a base material for the rebuilding of a half-mile stretch of a Karnes County road in the heart of the Eagle Ford’s liquids-rich fairway. A considerable portion of the road fill comprises recycled OBM cuttings generated from the two rigs that BHP Billiton is currently running in its nearby Black Hawk field. “Essentially, we’ll be driving over our own cuttings, which we think is pretty cool,” says BHP Billiton Associate Drilling Engineer Jorge Ramos.

In what is expected to be the first of many such donations, recycled oil-based drilling fluid cuttings are being used as base material for this rebuilt stretch of Karnes County Road 240. Image: BHP Billiton.

In a June 16 release, Polk Managing Member Mickey Polk described the donation as “an integral core aspect of Polk’s business philosophy that is predicated on reduce, reuse and recycle. Our ability to give back to the community, while assisting our customers in achieving their environmental goals through sustainable solutions, directly benefits our customers in the areas in which they operate.”

For BHP Billiton, that means not only taking OBM cuttings out of the waste stream and into beneficial re-use, but also no longer having to truck contaminated drilling solids to often-overtaxed landfills and hoping for the best. By recycling cuttings, the company says it reduces its per-well trucking and disposal costs by 57% and 65%, respectively, and eliminates the accompanying risks of intermingling its waste within a public disposal facility.

The cuttings dilemma. The recycling effort represents a central component of a sweeping waste management initiative that took root at the height of the Eagle Ford drilling frenzy. “When activity was going strong, and we had as many as 17 rigs in the Eagle Ford, we were generating thousands and thousands of barrels of cuttings,” Ramos said. “We were taking all these cuttings to disposal facilities, where they were being treated, buried and essentially unused. We knew we had to do something better.”

One of the first cuttings management concepts explored was on-site recycling, which upon landowner approval, involved mixing the cuttings with an aggregate for use in building drilling pads. However, between the aggregate and the additional cement required to meet compressive strength specifications for multi-well pads, that approach quickly proved counter-productive. “We trialed it on a pad, but when you add the amount of aggregate to the cuttings already generated, you’re basically doubling the (waste) volume per well,” Ramos said.

The exercise, nonetheless, was constructive, says Senior Drilling Engineer Carlos Bossi. “We proved that we can manage it (drill waste) in a safe way without any spills. It was a good step, because it triggered the next step, which was the off-site recycling of drill solids.”

Beneficial reuse. Enter Polk Operating, which opened its Karnes County R3 facility in 2013, making it the first company in the Eagle Ford specifically dedicated to recycling OBM cuttings. According to Polk, it remains the only commercial recycling facility in Karnes County permitted by the Texas Railroad Commission (RRC), the state’s chief regulator.

Polk and BHP Billiton joined forces in October 2015 with cuttings delivered to the R3 facility, where they are mixed with caliche and sandstone aggregate, and further treated to recover entrained base fluid and reduce the oil-on-cuttings ratio to meet the minimal specifications established by the RRC for off-site reuse. Treated cuttings that do not make their way into road construction are being recycled as fill material for a decommissioned uranium mine in Karnes County.

“With regard to recycling facilities, one issue worth noting is that the RRC only allows them to have a certain volume at their locations that are open to the atmosphere,” Ramos said. “Some have been forced to shut down, because they had excess capacity. Any excess that Polk has after road construction goes directly to the mine as fill-in.”

However, given the deplorable condition of Eagle Ford-area roads, and the field-proven validation of the recycling technology, it appears likely that excess capacity will not be a concern, even with future increases in activity and associated cuttings volume. “When things turn around, I think Polk will take all the drill cuttings we can send them,” Bossi says. 

About the Authors

Jim Redden

Contributing Editor

Jim Redden is a Houston-based consultant and a journalism graduate of Marshall University, has more than 40 years of experience as a writer, editor and corporate communicator, primarily on the upstream oil and gas industry.