A bird’s-eye view of oil exploration

There are places in the world that still have untapped oil —lots of oil. But they're hard to access and therefore expensive to develop, especially when it comes to ensuring their ecosystems are respected. A new technology may radically upset this status quo. METIS aims to complete the exploration and imaging phase virtually without setting foot on the ground. It's clearly a disruptive project that will require patience and acceptance in addition to technology. The enthusiast who has championed the project for the last three years unpacks it.

Approximately 450 billion barrels of oil equivalent¹ still lie untouched beneath the Earth's surface. And 15 percent of those resources are in areas geologists refer to as foothills. But there's a problem: These areas are also labeled "geological chaos" for their incredibly complex surface and subsurface, made up of folds and thrusts, which make development difficult if not downright impossible.

What's more, such areas are often found in remote corners of the planet, deep in hard-to-reach, hostile environments whose wildlife and plants are closely watched by multiple stakeholders. So it's not hard to see why these foothills weren't an oil company priority, for reasons of operational difficulty, profitability, social or environmental acceptance and risk management.

Nevertheless, as CEO Patrick Pouyanné points out in his video, The Future of Energy: "[Total's] technological capacity is at the heart of the future of the company." Especially when "competitive oil has a future."

Florent Bertini knows all about competitiveness and technical progress. He runs the Earth Imaging R&D (research and development) program in Total's Exploration & Production segment. Since the summer of 2014 he has been working with his teams on METIS², which he describes as "a disruptive and holistic project" to acquire very high-caliber geophysical data to produce subsurface images of foothills that can subsequently be used to explore their potential.

At the EAGE Conference and Exhibition 2017,
Total and its partners previewed the disruptive METIS project.

Disruptive it certainly is. In Florent Bertini's view, "We've been doing onshore seismic acquisition the same way for 50 years. Over that period, its offshore equivalent has made colossal strides. So we weren't thinking in terms of incremental R&D, of tweaking existing methods. We were saying to ourselves that, given ever tougher environmental requirements: 'We're not even going to set foot on the ground'." The makings of METIS in embryonic form date back to 2006, but the recent transformation of Total Exploration & Production's R&D is what really enabled the necessary industrial vision to take shape and be pursued.

The conventional method for exploring foothills is both high-impact and hit-or-miss. You have to hack out regularly spaced trails in forests to set out seismic sensors by hand. It's a slow-going, hazardous technique for the people involved, requiring huge resources such as helicopters and ultimately yielding poorer quality 2-D images. It combines environmental and safety risks with industrial uncertainty. It's a long way from "competitive oil."

"The METIS project will let us produce high-resolution 3-D images while minimizing the carve-out of trails," says Florent Bertini. "The solution is to drone-drop wireless geophones directly through the canopy. Exploration's environmental impact, especially deforestation, will plunge by a factor of fifteen."

The geophones, developed with partner Wireless Seismic, are 50-centimeter darts (the acronym DART stands for Downfall Air Receiver Technology). They are equipped with technologies that can log the signals emitted by various sources and then send the data back to the command and control center in real time. A geophysics computing center then processes and interprets the data virtually immediately, to produce a reliable image of the subsurface.

• For more on the subject: Tremors in seismic data

Darts sailing through a tree canopy is a somewhat scary prospect. Especially when you're talking about releasing up to 200,000 of them as part of a geophysical survey covering an area of 400 square kilometers. There are legitimate grounds for concern for the safety of people or animals caught in a dart's path, and for the impact on plant and wildlife ecosystems of a device packed with electronics. The receivers will not be recovered at the end of the survey. "That's why our darts will eventually consist mostly of biodegradable components," comments Florent Bertini. "The casing will be made from PLA (polylactic acid) blends developed by Total's Refining & Chemicals segment. The goal is for the darts to decompose in less than two years." Ditto for the DART's bio-electronics. For the batteries, discussions are in progress with SAFT, start-ups and university labs to develop a biodegradable battery model. Initial feedback suggests that the Bagnolet, France-based company might be able to produce a prototype within two years. The minimal amount of non-biodegradable components will be non-polluting, as defined by the applicable legislation.

Lastly, much of METIS's logistics will be handled by "flying wing" hybrid aircraft developed with the French company Flying Whales. "The HA2t airships will effectively partner with helicopters to transport heavy loads of up to two tons, acquire non-seismic data, serve as communications relays and perform medical evacuations. Their carbon emissions could be as much as 20 times lower than those of a helicopter," says the engineer.

With respect to the safety of people and wildlife: "We will never launch a DART through a canopy if we have any doubt at all about whether a person or animal might be directly in its flight path," promises Florent Bertini. The technical solution to ensure "safety clearance" arranges a master drone and slave launcher drones in a triangle setup so that they can perform an azimuth survey with an infrared camera and optical and laser devices, to analyze the canopy's internal structure and make sure there are no living creatures below. The main drone and the launcher drone will communicate with one another at all times and will fire the darts only when it is safe to do so.

In support of the technical solution, local residents will act as "observers" as part of a community buy-in plan. "They'll be brought in as partners and made responsible for monitoring all activity near the operations," he explains. The use of RFID³ chip devices to track movement is also being studied. Getting neighboring communities to embrace such technology-based approaches will require our community liaison teams on the ground to do "a lot of advance planning, communication and outreach work," warns Florent Bertini. You can see why.

• For more on the subject: Pangea, High-Performance Computing for 3D Oilfield Modeling