High-tech wildcatters pinpoint oil drilling to minimize costs, damage

Posted: Monday, April 02, 2001

ANCHORAGE, Alaska (AP) -- Stephen Lewis has struck oil. Again. He can do it a dozen times -- before lunch.

''If we extend along the shale cap and then take the well down through it,'' the BP Amoco PLC geophysicist explains, zigzagging through 100 million years of geology beneath Alaska's North Slope, ''we should hit more oil.''

Energy hasn't always been so easy to find. In the old days -- the 1990s -- a typical wildcat driller, bundled in coveralls and reeking of crude, might celebrate a gusher once every 10 or 20 test wells. At Prudhoe Bay, they drilled 100 times before hitting ''pay.''

At $4 million per, punching holes blindly into the Earth's crust is what makes the oil business more roulette than science.

Then there is Lewis, with his carefully brushed mane of white hair and shiny loafers. Snug in a suburban office building 600 miles from the frigid Arctic, he peers through distant ice and bedrock to find pockets of unexploited hydrocarbons.

Lewis doesn't have x-ray vision. Rather, he revs up a sophisticated imaging computer and dons a pair of boxy tan goggles.

The $1 million Highly Immersive Visualization Environment, or HIVE, enables him to digitally ''see'' for miles underground, where grinding pressures bake rocks at 300 degrees Fahrenheit and make fluids fizz like soda pop.

The HIVE resembles a large home theater, minus the cup holders and popcorn. A large curved screen embraces the audience. The room is painted black to eliminate glare and distractions.

With the 3-D glasses to enhance the image, you plunge down the borehole and into the reservoir, augering past, around and through a maze of hidden faults, mountains, valleys, stream channels and other buried geologic features.

Complex software enables Lewis to unpeel layers of rock deposits for likely pockets of energy overlooked by conventional analysis. Often he's able to tap the reserves by extending existing wells.

''It's like guiding rockets,'' Lewis said. ''The target might be 9,000 feet down and seven miles away, and the box we're aiming at is 20 feet long. We can put a well exactly where we want it.''

HIVE and other technologies could be crucial to pinpointing oil reserves beneath sensitive areas like the Arctic National Wildlife Refuge. That could reduce the number of new wells drilled, as well as the extra roads and pipelines connecting them.

''It's all about footprint,'' Lewis said. ''Optimizing every well bore would mean smaller drill pads and less infrastructure in the refuge.''

HIVE's sophisticated images are generated from millions of pages of data from several sources -- satellite data, drilling logbooks from nearby wells and, especially, three-dimensional seismic.

This improved seismic method uses vibration equipment rather than old-fashioned dynamite blasts. The acoustic returns are collected with a complex network of receivers, including sensors lowered below ground to add details collected at different levels.

3-D seismic can't see oil directly. Scientists must still interpret the images of the Earth's structure to guide the drill. Some compare it to a blurry sonogram of a baby in the womb.

''If you can't imagine oil, you'll never find it,'' said Catherine Hanks, a research geologist at the University of Alaska Fairbanks. ''Doing 3-D at the refuge would be very useful.''

A 3-D survey at the refuge would cost millions. Oil companies are unlikely to bear that cost unnecessarily, so the political decision to drill there most likely would have to occur first.

''You don't run 3-D on somebody else's acreage,'' said Anchorage geologist Arlen Ehm, who directed a two-dimensional seismic survey at the refuge 20 years ago. ''It's so expensive you only run it on a sweet spot where it's already been determined there is oil.''

End advance for Sunday, April 8

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