It was not long ago that finding a natural-gas field beneath your property was viewed universally as a stroke of good luck. Now, local natural-gas development is feared by many who assume the “new technology” of “fracing” is environmentally harmful. In reality, the first hydraulic-fracturing treatment was tested in a North Carolina granite quarry way back in 1903. Hydraulic fracturing has been used successfully in more than a million wells since then, and, currently, hundreds of fracturing stages are pumped every day. Very impressive for a “new” technology!
Partly because of these very successful and trouble-free wells, natural gas has enjoyed an enviable reputation as a clean, cheap, and abundant energy source. However, we need only to look to the nuclear industry to see that a hard-won reputation can be ruined by false rumors, isolated incidents, or the worst examples of safety, environmental, and reporting practices. If we always strive to be good neighbors in the communities in which we work, we can remain proud natural-gas producers for years to come.
Because stimulated wells make up an increasing portion of supply with each passing year, we have become dependent upon wells that require additional attention and often exhibit high decline rates. To buffer the supply/demand swings, gas-storage wells are used for both injection of dehydrated pipeline gas and production of newly saturated formation gas. Water-vapor equilibrium will reduce the water saturation around injection wellbores but may increase salt precipitation in the same region. A new study from the Middle East describes a means of maximizing sand-free gas-production rates from wells in unconsolidated zones, without a difficult-to-place hydraulic fracture. A third paper describes a means of identifying well candidates that may need a second treatment because of deterioration of the original fracture or the need to access additional reservoir. A downloadable full-length technical paper provides a new decline-curve functional form that can match unconventional wells with long transient-flow periods w hile honoring late-time interference and depletion. These papers provide some legitimately new technology.
Read the paper synopses in the November 2011 issue of JPT.
Scott J. Wilson, SPE, is a Senior Vice President of Ryder Scott Company. He specializes in well-performance prediction and optimization, reserves appraisals, simulation studies, software development, and training. Wilson has worked in all major producing regions in his 25-year career as an engineer and consultant with Arco and Ryder Scott. He is Cochairperson of the SPE Reserves and Economics Technical Interest Group and serves on the JPT Editorial Committee. Wilson holds a BS degree in petroleum engineering from the Colorado School of Mines and an MBA degree from the University of Colorado. He holds two patents and is a registered professional engineer in Alaska, Colorado, Texas, and Wyoming.
The science behind the use of microbes to enhance oil recovery has advanced significantly, but it suffers from old associations.
After decades of trial and error, those working on microbial enhanced oil recovery have identified the “oil-eating” bacteria that laboratory tests suggest can change the properties in an oil reservoir, and know better how to put them to work. The increasing knowledge of the role microbial life plays in oil and gas reservoirs has also led to new approaches for controlling corrosion, managing bacterially-produced hydrogen sulfide, and creating natural gas from coal.
(In this story, “eat” is used to describe the metabolic processes of bacteria. For instance, oil eating is more precisely hydrocarbon oxidizing.)
But the greatest potential payoff and the most debate come from the idea of microbes for enhanced oil recovery (MEOR). “There is a much greater understanding of what microbiology is doing in a reservoir” and how that can be used to produce more oil, said Stuart Page, chief executive officer of Glori Energy, a company that has staked its future of convincing the industry that microbes can be used to recover more oil.
Read the full article from the November 2011 JPT.