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New Exploration Techniques:
Direct Hydrocarbon or Mineral Indicators
A combination of non-invasive techniques (seismic, magnetic resonance, etc.) in Direct Hydrocarbon and Mineral Indicators, in order to detect the presence of hydrocarbons and minerals, to determine where to drill exploratory wells, and step-outs. (see below for more information)
3D Mathematical Modeling / GAMLS / Neural Networks
In addition, new methods of processing well-log data from a field can reveal overlooked reserves, or possible extensions to existing fields. GAMLS is one such software program, which allows geologists, geophysicists, engineers, and petro-physicists to evaluate old fields, look for step-outs, and to analyze the potential of new producing zones. (see below for more information)
New Drilling / Production Techniques:
Take horizontal drilling in the shale to new levels. In addition to drilling the shale zone and perforating the shale, we will now perforate the boundary regions above and below the shale. This may seem not only counter-intuitive: won't it result in formation damage? Won't it release all the unwanted formation fluids and gases (salt water, nitrogen, etc.)?
Benefits of perforating the shale and the perfing into the boundary regions:
Getting the oil from thin zones: Where shale has served as a seal for a small gas cap in a thin zone, it gives one the ability to effectively exploit the reservoir and extract the hydrocarbons effectively, without the water, etc. (example: Red Fork / Pennsylvanian sands in the MidContinent region).
Recovering hydrocarbons from depleted zones where there is nothing left but very thin zone of gas, with massive water behind it.
Perf the boundary region: Using the shale as both seal and controlled fracture / conduits where there is a massive water sand or massive carbonate reservoir with gas cap, (example: Mississippian in northern Oklahoma).
Perf the salt: Shale gas on the edge of anhydrites or salt seals: perf into the anhydrite.
Why? If you treat the anhydrite, it will change volume (swell) and will add pressure to the shale gas & will stimulate production.
Questions to investigate:
What is the extent of the Fayetteville shale? Some suggest that productive gas zones extend beyond the Arkoma Basin in Arkansas and well into Louisiana and central Oklahoma.
Has the Barnett shale been over-hyped? Perhaps the bloom is off the rose, and it is not economically viable to continue to pay quarter royalties to obtain leases on unproven acreage. The Barnett shale is expensive to drill and to produce. Further, the reservoirs may not live up to their billing. Thus, we may see more distressed properties / companies on the auction block (but discretely so). Opportunities will emerge to snap up properties from companies who do not have the liquidity to maintain their drilling programs or to stand in the dip in revenues due to a temporary (perhaps) collapse in gas prices.
Woodford shale and western Oklahoma: the shale is extensive, but in the Anadarko basin, is it too deep? Too difficult to produce? Too discontinuous?
Sylvan shale: Blending production strategies? Low-gravity oil mixed with gas? May require blended production / drilling solutions.
Pennsylvanian shale / sand sequences (fluvial deltaics) may require radical new approach to drilling and production. Go underneath or above existing productive reservoirs and horizontally drill the shale.
Perf the boundary. This will allow you to produce the remaining gas even when the oil-water contact has moved close to the shale seal.
New Analytical techniques - Reservoir Characterization and Shale Gas Sands:
Using a combination of non-invasive techniques (seismic, magnetic resonance, etc.) in Direct Hydrocarbon and Mineral Indicators, in order to detect the presence of hydrocarbons and minerals, to determine where to drill exploratory wells, and step-outs.
Connects with cluster analysis to
x---Develop model using attributes of producing wells, develop goodness of fit parameters
x---Develop model to determine sequencing of step-out wells, where to re-enter zones, and where to do in-field drilling for best drainage.
GAMLS - A new approach to reservoir characterization.
x---Demonstrated effective in several shale gas zones (including Barnett shale)
x---Attributes spatially presented, 3D visualization facilitates interpretation, reduce risk
Mid-Continent Shale Gas
Some have called the Barnett Shale the new Austin Chalk, while others draw parallels with coalbed methane. In each case, new technologies are making what used to be an uneconomic venture a highly profitable one. Shale gas is now being produced from the Barnett Shale and the Fayetteville Shale, while companies are starting to drill and produce gas from the Caney Shale. In other parts of the country, the Antrim and the Albany shales are of interest.
Schlumberger: Shale Gas overview
Finding Overlooked Reserves
In addition, new methods of processing well-log data from a field can reveal overlooked reserves, or possible extensions to existing fields. GAMLS is one such software program, which allows geologists, geophysicists, engineers, and petro-physicists to evaluate old fields, look for step-outs, and to analyze the potential of new producing zones. In many cases, the new zones have been overlooked because technologies to determine the zone's potential, and then to successful drill and complete the hydrocarbon-bearing formation did not exist. This was often the case with tight gas and shale gas, including the Barnett Shale and Fayetteville Shale, where permeability was measured in the milli-darcies. Technological advancements have led to the ability to economically produce shale gas, but it is very important to understand the lithology and petro-physical characteristics of the formations, as well as to be able to detect the presence of commercially viable quantities of hydrocarbons. Perhaps one of the most cost-effective ways to explore for shale gas within an existing field is to utilize programs such as GAMLS.
(For information on GAMLS, contact Eric Eslinger, Ph.D. at mulchone at albany dot net).
What is shale gas? from The Center for Energy.
Shale gas is conventional natural gas that is produced from reservoirs predominantly composed of shale with lesser amounts of other fine grained rocks rather than from more conventional sandstone or limestone reservoirs. The gas shales are often both the source rocks and the reservoir for the natural gas, which is stored in three ways:
* adsorbed onto insoluble organic matter called kerogen
* trapped in the pore spaces of the fine-grained sediments interbedded with the shale
* confined in fractures within the shale itself
In the Mid-Continent, numerous shales contain hydrocarbons, including natural gas. Shales include the Barnett Shale, Woodford Shale, Fayetteville Shale, and the Caney Shale.
Oil and Gas Investor's special section: Shale Gas
Arkoma Basin
Fayetteville Shale - February 2006 - AAPG Explorer - "Barnett May Have an Arkoma Cousin"
Barnett Shale - February 2006 - AAPG Explorer -- "Barnett Shale a Stimulating Play"
Other shales -- Woodford shale gas / Coalbed methane - PTTC Network News - 2004
Potential Gas Shales in Oklahoma -- Oklahoma Geological Survey - 2006
2006 Gas Shales Modeling -- upcoming in May 2006, sponsored by SRI Institute
Petroquest -- Woodford Shale test -- 2005 financial results
Petroquest Financial Information -- Lafayette, LA
photo from naturalgas.org
Questions? Further information?
Contact: S. S. Nash, Ph.D.
info@shalegasventures.com
Contact: smithnash at hotmail.com
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