Coring an exploratory well is a fine balancing process. Geoscientists need to compromise on how much data they want vs. how much they can obtain in a reasonable time frame. But when it comes to core analysis, which is often essential to subsurface understanding, the time frame can be anything but reasonable.

This issue has prompted many companies to try to deliver solutions in which most of the preliminary core analysis work is performed at the well site. One such company is PetroArc International (PAI), which since 2005 has worked with clients to deliver high-resolution, large-format imagery and provide image analysis services using virtual microscopy, a technology that has been used in the medical industry for years.

Perhaps it is best to start this discussion by addressing some of the issues that exist with the current technology. First and foremost is the time it takes to get preliminary results. It can take several months to receive core gamma logs and core imagery, and several months more to receive the results of laboratory tests. This creates two problems: 1) without the preliminary data, the client cannot pick plug points, increasing the time it takes to get results, and 2) as the results come in from the lab over time, they tend to disperse to the rock mechanics folks and the petrophysicist, increasing the likelihood that it can be lost.

PAI addresses the second of these issues with its CORSystem well information software. CORSystem bundles several virtual microscopes together with document and spreadsheet access, well log panels, and core log panels to provide users with access to all of their well data. “The biggest constraint in terms of the information our clients get from their cores is finding that information,” said Christopher Prince, president of PAI. “You can have the best, most complete archive in the world, but if you can’t get to that information, it is useless.”

PAI currently images client’s cores while they’re at a core lab for analysis. While most core imagery is limited to 300 dpi, PAI images are designed for analysis and have a minimum resolution of 1,360 dpi, equivalent to the resolution of a 10x hand lens. The virtual microscopes incorporated into the CORSystem include a core viewer, MicroPet, a virtual petrographic microscope for thin sections, and HDView, a virtual reflected-light microscope for plugs and cuttings. All of the microscopes contain analytical and descriptive tools specific to their purpose. For instance, in addition to the ability to pan anywhere in the core and zoom in to the point where a sand grain is the size of a pencil eraser, the core viewer contains tools for core description, a measuring tool, a dip tool, grain size comparator cards, and a “grain size wand” for creating size logs. Prince mentioned a friend who had seen the software and was impressed by its applicability to core analysis. “He said, ‘At last we have core analysis software we can import logs into rather than a log analysis program that we can import core data points into,” Prince said “He was just delighted by that.”

PAI addresses the “time” issue by providing high-resolution imagery quickly. Currently, the imaging technician only needs a table and an electrical source to image the core. The next step is to make the service truly portable. Prince and his business partner Nelson Heskett are currently shopping for a trailer that will contain all of the tools to process the core at the well site. PAI will retrieve the core; cut it into 1-m (3-ft) tubes; and perform gamma logging, slabbing, and imaging. “When we’re done, we’ll deliver the core to whatever lab they want it to go to, and we’ll have all of the imagery and the gamma log to the client within a week,” Prince said.

Overall, he said, “Our goal is to make all of the information available. We’re trying to give them one-click access to all of their archived information.”