Release Date: June 12, 2007
|New Seismic Technology Improves Pre-Drill Diagnostics
for Deep Oil and Gas Reservoirs
WASHINGTON, DC - New technology developed through a cost-shared project managed by the Office of Fossil Energy's National Energy Technology Laboratory is improving industry's ability to identify commercially viable deep oil and gas targets prior to drilling. Applications of this groundbreaking technology will help to accelerate future development of deep oil and gas resources in the United States.
As the oil and gas industry turns its attention toward deeper targets, particularly in the Gulf of Mexico, the tremendous costs involved require advanced technologies for pre-drill evaluation of a deep prospect's location, size, and hydrocarbon charge.
Rock Solid Images, of Houston, Texas, answered the call with their much-needed pre-drill seismic imaging technology. The patented new technology improves pre-drill oil and gas detection in the reservoir and reduces the risks associated with drilling deep wells. With a significant portion of the Nation's oil and natural gas resource trapped in deep reservoirs, the new seismic technology represents a much-needed improvement that should bring more deep oil and gas to market.
Deep resources are defined as those located in reservoirs at depths of 15,000 feet or greater. Although less than one percent of all wells in the United States have penetrated below 15,000 feet, such wells account for a significant portion of domestic gas production. And production from deep reservoirs must continue to grow in order to keep pace with the Nation's natural gas needs. Recent discoveries of deep oil accumulations in the Gulf of Mexico indicate that deep oil will also add significantly to the U.S. reserve base in future years. But the extreme high costs of drilling these deep wells means that only the most promising seismic targets are actually drilled and produced.
The biggest challenge to developing deep oil and gas resources is identifying commercial quantities of oil and gas prior to drilling, and seismic imaging is the technology of choice for this process.
However, conventional seismic imaging and attribute analysis becomes less reliable the deeper the target. The acoustic energy attenuates and loses strength as it travels through successively deeper layers of rock, which results in poor image resolution and less reliable hydrocarbon detection for deep oil and gas prospects. In the case of deep natural gas prospects, the imprecise seismic data can incorrectly indicate the presence of a productive gas reservoir when in fact the reservoir contains only traces of gas, or no gas at all.
The new seismic processing technology from Rock Solid Images is aimed at improving the pre-drill diagnostics for deep reservoirs using a set of independent indicators known as seismic attenuation attributes. These attenuation attributes can safely confirm the presence of oil or natural gas in deep reservoirs where conventional techniques prove unreliable. Essentially, the degree of attenuation is used to track the amount of gas or oil in the reservoir, and combined with conventional seismic analysis techniques, such as Amplitude Versus Offset analysis, these attenuation attributes can effectively confirm or disprove the presence of oil or gas at depth, avoiding the risk and expense of drilling an unconfirmed well.
The modeling software was tested offshore Norway where conventional seismic attribute analysis indicated possible hydrocarbons beneath a well drilled to 14,000 feet. Rather than drill a deeper well to test the seismic anomaly, the operator hired Rock Solid Images to apply their seismic attenuation technology to confirm or refute the presence of hydrocarbons in the target interval. Through rigorous forward modeling, using available log and seismic data, Rock Solid Images found that the anomaly was caused by a marked change in rock type, rather than oil or gas in the reservoir, and saved the operator millions of dollars.
In addition to the Norway test, the modeling software has been successfully tested in the deep Gulf of Mexico and offshore West Africa.
This technology is commercially available through Rock Solid Images' iMOSS software package and has been adopted and developed for internal use by several major oil companies. Rock Solid Images also provides its attenuation technology as a service to a number of oil and gas operators worldwide.