On the heels of a successful two-year study of the potential of military lasers to drill for natural gas, researchers at the Gas Technology Institute have teamed with the US Department of Energy and with university and industry partners to assess the commercial viability of laser drills for the petroleum industry. Such drills would represent the most significant technological advance in the industry since the advent of rotary drilling a century ago. Lasers promise several advantages over mechanical techniques. They not only could offer a penetration rate of more than 400 feet per hour, but, because they create a ceramic sheath as they drill through rock, the need to stop and pull out of a borehole to reinforce it with steel casing would be eliminated. Moreover, the laser head could incorporate a sensor array for real-time monitoring down the hole, again eliminating the need to stop drilling. All of this would add up to a great economic benefit. "It costs $250,000 to $400,000 per day to drill on offshore rigs," explained Richard Parker, principal technology manager at the institute and project director of its E&P Services Div., "so saving time translates into saving money." The project was born out of a challenge to envision revolutionary drilling techniques. In 1997, the institute and its partners at the Colorado School of Mines in Golden sought to beat swords into plowshares. They investigated the interaction of lasers with samples of rock, using the US Air Force's chemical oxygen iodine and CO2 lasers and the US Army's mid-infrared advanced chemical laser. What they found surprised them. "In the 1970s, military researchers estimated that it would take much more energy to break rock with lasers," Parker said. "They were wrong." Getting quantitative The next step is to get quantitative. The new study will establish how much energy is needed to drill through different types of rock, evaluate the performance of pulsed lasers and demonstrate the ability to drill in the weighted fluids used to control pressures in the borehole. The team has industry support from Petroleos de Venezuela SA and Halliburton Energy Services and has recruited the assistance of a group of researchers at Argonne National Laboratory, who have reported success ablating radioactive concrete with a pulsed Nd:YAG. "The plan is to come out of the three-year study with a workable design," Parker said. "I think we can have a prototype in the field two years after that. ... In 10 years, I'd say, we'll have a commercial product."