A team of structural geologists and seismic processing geophysicists has developed what they believe is a potentially revolutionary technology that can help predict hydraulic fracturing performance before a well is ever drilled.
What the team cannot predict, however, is when the technology will rock the industry and become a pervasive, indispensable tool – much like 3-D seismic, which started its long journey toward acceptance in the 1980s.
As is the case with most new technology, Ambient Seismic – a product of Global Geophysical Services – is catching on in the industry, although not at breakneck speed.
“A good analogy is the 3-D printer. It’s so new that no one knows what to do with it,” said AAPG member Charles Sicking, vice president of research and development at Global, and one of the developers of the technology. “They can see the value but need time and experience to determine how to use it.”
So, like anyone who believes in his product, Sicking and his colleagues have been going door to door, so to speak, and demonstrating its unprecedented capabilities to potential clients.
“This technology can help you plan ahead. People are drilling less now. If you put in a well, you want and need it to be a successful well,” said AAPG member Jan Vermilye, chief geologist for tomographic fracture imaging and manager of Ambient Seismic processing and interpretation at Global.
Ambient Seismic records the acoustic activity from natural fractures in the earth. Based on those acoustics, maps of fractures can be generated as predictive guides for hydraulic fracturing operations, explained Vermilye, who worked with Sicking on the development of the technology.
“We provide the roadmap before the trip begins,” Vermilye said. “Before you drill, you look at the map and decide if it’s a fracture network that should be avoided or should be used to help deliver oil or gas to the well.”
Seismic emissions are released when rocks break naturally from various forces within the earth. A measurement of low emissions indicates the presence of low fracture density or small fractures, and a measurement of high emissions indicates the presence of high fracture density or large fractures.
“If you have a location with hydrocarbons and it is highly fractured, these fractures provide for storage and for transmission of the hydrocarbons to the wellbore,” Vermilye explained.
Unlike microseismic events, which are small earthquakes, Ambient Seismic emissions are low amplitude signals that can be collected and stacked over an extended period of time – anywhere from one minute to several days, Vermilye said.
“We are not just picking one-time events,” she said. “We are stacking all of the energy released.”
And, unlike 3-D seismic surveys, which provide images of larger fractures and faults in the earth, Ambient Seismic captures smaller structures and shows active deformation, Sicking added.
That is the key to the technology’s predictive ability: Fractures that help produce oil are generally smaller than those typically detected by 3-D seismic, Sicking said, and they don’t have large enough offsets across the fractures to be imaged with 3-D seismic.
Long before the industry’s downturn, the concept of Ambient Seismic was in the works to offer a more affordable way to drill and produce.
It began with Peter Geiser, a visiting seismologist at Columbia University who had the idea to map the natural energy released within the earth, recalled Vermilye, who worked with Geiser after he founded STRM LLC – a company that developed seismo-tectonic reservoir monitoring methods – in 1998.
Initially, STRM hired Global, which employed Sicking, to provide acquisition services for one of its projects. Impressed with STRM’s fracture mapping technology, Global acquired the company in 2011 to incorporate STRM’s reservoir monitoring methods into Global’s budding microseismic division.
Sicking, who is a geophysicist, recalled early conversations with Vermilye, who is a structural geologist. Paired to help develop the frac prediction technology, “We sat down to begin discussions on how to merge the two technologies but had trouble communicating with each other in technical terms,” Sicking said. “We didn’t understand each other’s language. She was a fracture expert and I knew about seismic waves.”
After jumping the high hurdle to learn each other’s language and expertise, technological magic began to happen, and Ambient Seismic’s predictive abilities gave rise to additional applications.
Maps of natural fractures in rocks were produced specifically for frac monitoring operations. These maps showed what was happening in the reservoir rocks during the frac treatment. Later, technology was developed that allowed clients to map the induced fractures during the frac treatment. This evolved into Ambient Seismic production monitoring technology, which allows clients to map producing rock volumes and determine if infill wells or re-fracturing are needed.
“We can now make maps of producing volumes and determine which stages in wells are producing fluids,” Sicking said. “If you have 40 stages but are only getting production from less than half of the stages, we can map the volumes from Ambient Seismic recordings and tell you which stages are producing without having to put a tool into the well.”
Sicking admits he was considering retirement before the Ambient Seismic project came along.
“It was an opportunity to work on something that is brand new and totally revolutionary,” he said. “I’ve become more of a salesman.”
Here is his pitch: “What if a geophysical service company came to a client and said, ‘We have all of this great 3-D seismic survey technology, and we can make great attributes and tell you where the fracs are, but you have to pay us while we are doing the work and you can’t look at the data until after you drill your wells.’
“That would get a laugh, but that’s today’s microseismic technology,” Sicking said. “Companies drill a well based on 3-D seismic reflection surveys and design a frac treatment. They treat the well according to plan and lay out geophones to record data during treatment. Microseismic data is not recorded until the treatment plan is being executed.
“When using the current mainstream microseismic technology, you get data back that tells you what you did in the past,” he said. “There is no predictive value.”
On the other hand, the Ambient Seismic method records data before a well is drilled and predicts the locations that will yield the best production and performance based on the natural fracture system in the rocks.
“We map the fractures and show which produce the most acoustic activity and are the most transmissive” Sicking said. “This provides the predictive value.”
Sicking and Vermilye, like all innovators, have a vision: Every oil patch will one day use Ambient Seismic.
“We are at the very beginning of industry adoption,” Sicking said. “We are not there yet. When we get there, everyone will want to apply the technology, clients will recognize its value, and they will see it as a standard method to use and they will no longer be worried about a fledgling development.”
Today, many of Global’s clients hire the company to reprocess existing data recorded for older frac monitoring methods but failed to yield enough useful information. Global provides added value that is extracted from the old data, helping to explain well and stage performance problems, identify locations for infill wells and determine how wells are performing.
“This technology is so new and so different from anything anyone has ever seen,” Vermilye said. “People think it is really interesting but they are afraid to go out on a limb with something completely new.”
In many cases, clients want to see if the maps generated by Global are consistent with their internal data before taking a risk. When they learn that this is the case, they return with additional projects.
“However, it is the engineers who are responsible for designing the fracs, and they have their way of looking at the world,” Vermilye said. “It’s important that we make the Ambient Seismic data relevant to their workflows and issues, and make it easier for them to incorporate data types and products that they are not accustomed to.”
Once engineers open their minds to new ideas, “They’re ours,” Vermilye said. “They don’t want to go anywhere else.”
Despite the fact that Global has worked on scores of wells across the nation and around the globe – including the Permian, Eagle Ford, Marcellus and Haynesville formations, and shales in China and Colombia – many of their clients choose to keep their results confidential.
“Operators like to maintain their competitive advantage and are reluctant to share their information,” Vermilye said. “We have some wonderful results that we would love to show as well as publish in papers, but most of our clients are not yet ready to share their results.”
That reality leaves Global with few options with which to market its product. Today, they rely heavily on giving presentations, participating in industry events, pitching articles to trade publications and offering clients discounts if they allow their results to be shared.
Around the Bend
Confident their technology will catch on, Sicking and Vermilye are currently working on ways to improve it.
During a hydraulic fracturing operation, it currently takes approximately four weeks from frac completion to deliver the Ambient Seismic products.
“I would love to do it in real time or near real time,” Vermilye said. “We have developed a workflow for this, but we have not yet had an opportunity to apply that workflow. We need a client who has a need for this and wants us to do it.”
Sicking is ready to go even further and predict what will happen during hydraulic fracturing and production – ahead of time. If the predictive value of the Ambient Seismic method becomes well established, there will be less need for real-time monitoring during the frac treatments.
“We can do it,” he said. “I have a plan!”
Engineering in the oilfields has experienced an evolution in the last four to five years, Sicking said, explaining that engineers now realize that not all rocks fracture in the same way.
He believes many engineers are coming around to the idea that hydraulic fracturing is a reservoir-wide operation that requires further study and innovative technology.
As operators begin to shift their focus from today’s well-to-well approach and begin to use a predictive, reservoir-wide management approach, the industry will be forever changed.
“It could save a huge amount of money,” Sicking said. “You would have the same amount of oil production or even more, but significantly reduced production costs.”
This would mean unconventional reservoirs could make a profit at a much lower oil price.
“I am past retirement age and still working,” Sicking said. “This is one of the more chaotic and exciting times of my career. But I am here because I believe this is going to bring a paradigm shift to the industry.”