New Solutions Enhance Well Fracturing
By Danny Boyd, Special Correspondent
With horizontal resource plays continuing to set the tone for North American operators, it comes as little surprise that the forecast calls for an increase in hydraulic fracturing services in the years ahead.
Dust Control System
With respirable crystalline silica dust identified as a health, safety and environmental concern for federal regulators, KSW Environmental, a division of Houston- based Dupre Energy Services, has developed a method and the equipment for dust control using a vacuum or “local exhaust ventilation” (LEV) system, says Santo Petitto, general manager of KSW Environmental.
The company’s licensed technology was issued a method patent in October (U.S. patent 8562720) and an apparatus patent in January (U.S. patent 8636832 B2), he says. The KSW Environmental unit includes a 45,000 cubic foot per minute dust collector attached to the sand chief, t-belts, dragon’s tail, hopper and blender, Petitto explains.
The configuration is connected to larger manifolds, and collected dust is augured into large sacks, typically capturing about 800 pounds of respirable dust per 300,000 pounds of sand, Petitto says.
Controlling dust on site not only improves employee safety, but also helps service companies save on equipment wear from dust affecting millions of dollars’ worth of high-pressure pumps on each location, he goes on.
“We have had companies tell us we are saving them thousands of dollars each week in air filters alone,” Petitto comments. “Extending the life of a multimillion-dollar frac pump creates enormous savings and improves overall mechanical integrity.”
But a primary driver in the march to reduce respirable silica is OSHA’s proposal to cut permissible exposure limits (PELs) to silica dust in half, Petitto points out. OSHA is proposing to reduce the PEL from 100 micrograms of respirable crystalline silica per cubic meter of air averaged over an eight-hour day, to a PEL of 50 micrograms, he says. In addition, the proposed rule creates new requirements for training, engineering controls, respiratory protection, record keeping, and medical surveillance.
KSW Environmental’s system addresses all six areas identified by the National Institute for Occupational Safety & Health as sources of equipment-generated dust, Petitto adds.
“A lot of operators and service companies have recognized that more needed to be done than simply having workers wear respirators,” Petitto says. “That is where dust control equipment comes in. It provides those engineering controls. We can hook to the sand storage units, whether they are silos, vertical or horizontal units–whatever the sand delivery mechanism is.”
As of mid-June, the company had mitigated respirable dust in fracturing jobs involving more than 6,000 total stages, he reports. The system was developed by a company known as Frac Sand Dust Control. In late 2012, Dupre acquired the exclusive license to FSDC’s systems and technologies along with its frac site dust collection business and name, and formed KSW Environmental to focus exclusively on frac site dust mitigation.
In addition to deploying its equipment in the field, the company has presented exposure monitoring test results at meetings of the Service, Transmission, Exploration & Production Safety Network (STEPS), Petitto says. The organization’s Respirable Crystalline Silica Focus Group is working to identify solutions and bring awareness to the respirable dust issue, he says.
KSW Environmental’s findings from five customer tests with 88 personal breathing zone (PBZ) samples showed customers in compliance with OSHA exposure limits, according to Petitto, but the company is working to improve that performance even further. He says the company initially focused in areas such as the Marcellus Shale, where Frac Sand Dust Control’s solution was developed, but the systems now are deployed in the Marcellus, Permian, Eagle Ford and Rocky Mountains.