Biodegradable polymers are a tiny slice of the broader bioplastics market, but they could offer a means for oil and gas drillers to go greener in hydraulic fracturing operations.
It is almost common knowledge these days that advancements in hydraulic fracturing and horizontal drilling, both decades-old techniques, have been the keys to unlocking vast gas and oil deposits in recent years that were previously considered too costly to develop. As hydraulic fracturing has become commonplace across large swaths of the United States – sometimes in areas in which oil and gas drilling is a relatively new phenomenon – it has sparked a range of environmental concerns. These include fears that the materials injected into the ground in the process, which include chemicals and proppants, may contaminate water supplies.
Biodegradable polymers have the potential to help mitigate environmental concerns associated with hydraulic fracturing by offering an environmentally preferable alternative to materials currently used to suspend proppants, according to principal analyst of specialty chemicals at consultancy IHS Michael Malveda.
Hydraulic fracturing generally involves injecting a solution comprised of water, chemicals, proppant – such as sand – and other materials into a well. The resulting pressure creates fissures in rock that release trapped oil and gas. “When that pressure is relieved, the proppant needs to stay behind like a doorstop to maintain the openings that allow the oil and gas to come out,” said IHS chemical consulting director Ray Will.
Biodegradable polymers can be used as an accessory to the proppant, forming a gel that helps keep the proppant suspended, said Wills. He compared it to an ingredient in salad dressing that keeps the herbs suspended throughout the dressing, rather than clumping together.
Many hydraulic fracturing operations use guar gum as a suspending agent for proppants. But a dramatic run-up in guar gum prices last year squeezed oilfield service company margins and highlighted the need for alternatives to mitigate supply risks.
With further research and development, biodegradable polymers could prove to be a viable alternative, and they also have the advantage of being environmentally benign. “They are suspending the proppant particle in a way that doesn’t cause a deleterious breakdown product,” he said. Both Will and Malveda noted that companies are coming under ever-increasing pressure to conduct oil and gas drilling operations in ways that are considered environmentally sustainable.
But “the biodegradable polymers industry is still very young”, Malveda said. “This is more along the lines of an emerging technology as opposed to a mainstream, commonly occurring technology.” He estimated that it comprises about 1%-2% of the total biodegradable plastics market.
And questions remain as to its viability as an alternative suspension agent, especially as research and development efforts are targeting a number of other potential alternatives. “This is truly a good, green alternative, it’s going to have good prospects for the future,” said Will. “But it’s difficult to say that this is a clear winner, given the many things that are being examined.”