New developments in digital rocks and digital outcrop models continue to put more data — and more realistic data — on geoscientists’ desktops.
X-ray computed tomography yields insight into rock microstructures. Tiny samples are scanned at high resolution and reconstructed as 3-D images, which can be used for virtual simulations and experiments to analyze the interaction of porous rock s with the fluids that flow through them.
On another scale, the use of aerial drones coupled with photogrammetry software to create virtual outcrop models to put fieldwork on the desktop (see related story).
“The impact of this technology is going to be huge,” predicted Pankaj Khanna, a geoscientist and recent doctoral graduate in the Earth, Environmental and Planetary Sciences Department of Rice University.
“Building digital outcrop models is going to be the next basic understanding which every geologist would need to learn in the future. These models will be the future base maps for any geological studies,” Khanna said.
“Already, many companies have started building their databases for 3-D digital outcrops, using them as base maps and populating data like well-logs, cores, seismic, measured sections, thin sections on top of the outcrops. As the world is getting technologically advanced day by day, I predict these digital outcrop models will be the next revolutionary step to integrate geology more with software, making it more hands-on and easy,” he said.
Synergy of Developments
Promising new developments include improved laws and regulations for flying drones, better and more inexpensive drones, improved processing software, and AAPG’S Digital Immersive Geoscience (DIG) program, which aims to promote publication of 3-D digital outcrop models, he said.
Khanna noted that a new fluid-lensing technique also allows researches to remove water from images of ocean and lakebeds taken at shallow depths.
Advantages of the technology include the potential to build in-house databases and in-field base maps, he said.
“The in-house database is a great tool to introduce students/geologists to the rocks by virtual field trips. This way, students in class at a university or industry could be informed and trained about the field area using digital outcrops. The training could be question specific — deepwater outcrops, carbonates, fluvial systems — and their morphologies and facies.
“The in-field base maps are a great tool to carry in the field where the students in training could see the rocks and at the same time look at the regional architecture of the field area/basin on iPads or phones, aiding in enhanced understanding of the subject,” Khanna said.
He said upcoming challenges include development of a common, user-friendly database that could be accessed by all, perhaps through inexpensive subscription, and quality control.
“There need to be certain measures to be sure that the quality of the data is presentable,” he said.
Peer review is a possible solution, he said.
Khanna said the technology is being applied to understand both modern and ancient systems in several areas around the world. North America and Europe are leading the way in geological studies utilizing drones.
“The discovery of hydrocarbon reservoirs in pre-salt microbial accumulations offshore Brazil and Angola, in addition to a significant microbial component in some of the world’s largest carbonate reservoirs in the pre-Caspian Basin, has renewed interest in microbial deposits. Spectacular outcrops of upper Cambrian microbial reefs in Mason County, Texas, offer unique opportunities to assess varying scales of their spatial variation and potentially serve as subsurface analogs to improve reservoir correlation and modeling,” said Khanna. “I have built digital outcrop models of these upper Cambrian reefs and conducted qualitative and quantitative spatial statistical analysis to understand their spatial architecture and heterogeneity.”
Big Data Sharing
At the micro level, digital rock physics complements the laboratory and field work that geologists, petroleum engineers, hydrologists, environmental scientists and others traditionally rely on. Last year, the Texas Advanced Computing Center at the University of Texas in Austin launched the Digital Rock Portal, where researchers can store, share, organize and analyze the structures of porous media using the latest technologies in data management and computation. The project was funded with a National Science Foundation grant as part of EarthCube, a large NSF-supported initiative that aims to create an infrastructure for all available Earth system data to make the data easily accessible and useable.
Because the volume of data that can be derived from one tiny sample can be huge, files can be too large for most email servers and the storage requirement for companies can become a challenge.
The portal offers exploration companies free and unlimited data storage in exchange for making their computed tomography (CT) images of rocks available to outside researchers.
The platform allows managing, preserving, visualization and basic analysis of available images of porous materials and experiments performed on them, and any accompanying measurements (porosity, capillary pressure, permeability, electrical, nuclear magnetic resonance and elastic properties, etc.) required for both validation on modeling approaches and the upscaling and building of larger (hydro)geological models.
BP’s Digital Rocks Program
BP established its own proprietary digital rocks program 10 years ago using rock core samples acquired from exploration, appraisal and development wells.
The algorithms that simulate the physics necessary to characterize rock properties are run at BP’s Center for High Performance Computing in Houston, one of the largest supercomputers in the world dedicated to commercial research.
BP has applied the technology across the globe, including fields in Angola, the Gulf of Mexico, the North Sea, Egypt, Azerbaijan, the Middle East, India, and Trinidad and Tobago.
The company recently announced a new multi-year commercial agreement with Exa Corp., which will enhance BP’s ability to predict the flow of oil and water in digital images of reservoir rock.
The company announced that new multiphase flow simulation technology will help engineering teams to make more informed decisions on wells, production facilities and resource progression, including enhanced oil recovery.
Exa’s multiphase fluids simulation solution for digital rocks was co-developed with BP during a three-year technology collaboration agreement.
“After years of cooperative research and development, this breakthrough represents an important step forward for BP and for our industry,” said Ahmed Hashmi, BP’s head of upstream technology.