Albert Einstein suggested a century ago that large-scale cosmic violence—two black holes colliding, for example—might send gravitational ripples through the universe like a stone disturbing the surface of a pond. In September physicists in the U.S. conclusively detected gravitational waves for the first time, again proving Einstein right. While it’s a safe assumption he wasn’t thinking about how building a wave observatory might lead to finding oil and gas, two physicists in Amsterdam have started a company betting they can.
Innoseis’s prototype seismic sensor, not much bigger than a fist, looks like a box with a golf tee sticking out of it. Royal Dutch Shell, which is testing Innoseis’s sensors, hopes the lightweight, wireless technology can replace its standard surveying equipment. Each of Shell’s $100 million seismic explorations requires about 100,000 11-pound sensors, strung together with 6,000 miles of cable. Innoseis’s model, which is stomped into the ground every few yards, would in theory let the oil company deploy 1 million 1-pound sensors, covering much more ground, for the same price.
Innoseis’s path was obvious only in retrospect. Johannes van den Brand, an astrophysicist at the Dutch National Institute for Subatomic Physics, joined the hunt for gravitational waves in 2006, attracted by the scientific and engineering challenge. In 2009 he persuaded Mark Beker, a half-Dutch New Zealander with a master’s in applied physics, to pursue a Ph.D. in seismicity and gravitational-wave detection. To Beker, the research was a chance “to make what seems like science fiction no longer science fiction.”
Detecting how gravitational waves warp 3D space is tricky. The ripples are tiny. Instruments must be sensitive to 0.000000000000000001 meter, or about one ten-thousandth the width of a proton. And the earth, with its constant rattle and hum, is a terrible place to look for the waves.
To detect ripples, gravitational-wave observatories isolate their instruments from the earth’s interference. To subtract out low-grade seismic activity, or “Newtonian noise,” the facilities measure the ground outside and adjust accordingly.
Beker spent his first year of Ph.D. research on a seismic-listening tour of Europe, working on a way to account for Newtonian noise. He recorded what’s shaking, literally. In Germany he measured the ground near a factory. “You could tell from the seismic signal when people started, when they took a lunch break, and when they’d go home,” he says.
He and Van den Brand went looking for lightweight seismic sensors and wound up designing some themselves. In 2012 their research caught the attention of Wim Walk, a physicist who manages Shell’s seismic oil-hunting technology. The company needed to investigate earthquakes near facilities around the Dutch town of Groningen, where natural gas extraction has been linked to seismic activity. Walk suggested that Innoseis refine its sensors: They had to be small, cheap, and tough enough to survive extreme temperatures, or the occasional truck wheel.
The company is still testing Innoseis’s equipment. The prototype combines an analog instrument that measures ground movement with a software system that dramatically shrinks power demand (and thus weight and cost) by switching on gear only when it needs to time-stamp fresh data.
For scientists, Einstein’s gravitational waves offer a way to learn things about the nature of the universe, Beker says. Until now, astronomy was “like watching a symphony play without sound,” he says. “It’s like, all of a sudden, somebody turns on the music. You get to understand so much more. You get to see so much more.” Including, perhaps, a lot more oil.
The bottom line: Innoseis’s sensors may be able to increase the range of Shell’s $100 million oil exploration projects tenfold.