DALLAS - Geologists and geophysicists searching for oil are using computers to construct complex models of geological formations underground to help determine where to drill wells.
The approach is based on combining computer graphics and data bases in a technique called interactive modeling, in which images on the screen are manipulated to examine interesting underground formations that might contain oil.
The data come from observations of geological features below the surface of the earth, records of the formations penetrated by earlier wells in the area and information recorded when underground explosions are detonated to generate seismic signals in the search for oil.
The technology means that with a few keystrokes on a computer keyboard a geologist or geophysicist can transform vast quantities of exploration data into multicolored two- and three-dimensional underground diagrams. This eliminates much of the time-consuming calculations, drawing and research that have characterized exploration in years past.
Interactive modeling is growing in oil exploration because several forces have come together.
At a time when personal computers have become steadily more powerful and their cost has fallen dramatically, the oil industry has found itself in a cost-cutting squeeze brought on by the decline in recent years in the world price of crude oil.
As petroleum companies have tightened their belts and laid off workers - including highly trained geologists and geophysicists - the demand has grown for cost-efficient oil exploration methods that maximize automation.
``Interactive modeling is a very exciting field because you are able to transmit your ideas into the computer,'' said David R. Matuzak. a geologist and computer expert for the Amoco Corp.
He began working with computers in oil exploration more than 25 years ago. ``It gives you a lot of flexibility, which is important, because that's the way oil is found, through creativity, imagination and knowledge.''
Several small computer companies have appeared in this new market.
Sales this year are estimated at $80 million, and are expected to triple, to around $250 million, in the next several years, said Peter D. Schleider of Wessel, Arnold & Henderson, an institutional research firm in Minneapolis.
Industry experts say that a growing number of oil well discoveries, in both explored and unexplored areas, have been made using the computer modeling technique.
The technology is also being extended to interpret satellite images of oilfields and produce a new type of map.
Map making has been the traditional tool of oil exploration.
Experts interpreted the data and drew maps, laboriously coloring them by hand to indicate different underground formations and the potential that they held for oil.
Now the computer systems are taking over much of this work, performing on the screen in minutes what geophysicists and geologists in the past spent weeks to do, using reams of paper and colored pencils. …