Exploration
techniques have progressed from surface observation and divining rods to the use of satellites, microprocessors, remote sensing, and super computers to generate three-dimensional and four-dimensional time-lapse imaging of subsurface reservoirs. Sharply increased drilling success rates have cut the number of both wells drilled and dry holes.
Drilling And Completion
technology has advanced from gravity-driven cable tools in vertical wells to top-drive rotary rigs, coiled tubing units, advanced drilling fluids, and systems that monitor wellbore conditions during drilling operations. Current technology allows directional and horizontal drilling to reach previously inaccessible resources as well as to drill in deeper offshore waters. Durable forged alloys and polycrystalline diamond have replaced brittle cast iron bits, boosting drilling productivity and efficiency. Enhanced worker safety, habitat protection, lower and less-toxic waste volumes, and increased well productivity are the results.
Continual Innovation
over the last three decades has enabled the energy industry to drill ever deeper, with fewer dry holes, and to recover more reserves per well drilled. Sophisticated imaging technologies, including 3-D seismic and 4-D time-lapse systems, have provided oil and gas professionals with detailed pictures or reservoirs and formations, enabling more accurate and productive exploration and development efforts. These and many other advanced E&P technologies have literally redefined reserves. Oil and gas depths recently considered unreachable can now be tapped. Smaller accumulations once thought to be uneconomic can now be produced profitably. Fields under wetlands or cities can be accessed without disruption of the surface.
Particularly impressiveis the industry's track record in effectively extracting additional resources from previously discovered, older fields. Since 1990, the vast majority of reserve additions in the United States -- 89 percent of oil reserve additions and 92 percent of gas reserve additions -- have come from finding new reserves in old fields. Recent studies found that about half of these additions are from development-dominated growth (growth from more intensive development within the limits of know reservoirs), with the other half coming from more exploration-dominated growth (growth from finding new reservoirs in old fields and in extending the boundaries of oil fields).
As E&P capabilities continue to grow, so does the consensus of estimates of recoverable U.S. oil and gas resources. for example, in the 1970's the consensus of estimates of ultimately recoverable gas resources was on the order of 400 trillion cubic feet (Tcf). Today, adjusting for what has already been produced, estimates range from 1,200 to over 2,000 Tcf.
Today, finding black gold is a high-technology venture. Higher success rates mean fewer dry holes, fewer wells drilled, and less impact on the environment.
