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| Last: |
$0.31 |
| Volume: |
3750 |
| Change: |
-0.05 |
| Date: |
12-03-2008 |
| Time: |
15:35 |
15-20 min delay
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The 6,000-square mile, gas-rich Piceance Basin straddles the Colorado River and Interstate 70 in Garfield and Mesa counties and extends northward into Bio Lanco County and south to Gunnison and Delta Counties in Colorado. Its name comes from an Indian dialect, translated as "tall grass
The Basin is a large fluvial system that contains vertically stacked sequence of sands and shales deposited by a river system during the Cretaceous age 70 million years ago. The Piceance is a basin-centered gas trap speculated by the USGS to contain as much as 200-to 300 plus trillion cubic feet (Tcf) of gas resource in place.
Operators in the Piceance, including EnCana Corp. Williams Cos, Bill Barrett Corp, Laramie Energy and Teton Energy Corp, are recovering gas mainly from the 510- to 70 metre (1,700-to 2,400-foot) thick, gas bearing sequence in the Williams Fork section of the Mesaverde formation; the Williams Fork typically occurs at depths ranging from 1,300- to 2,550 metre (4,500 to 8,500 feet) in the basin.
Currently, Mesaverde drilling activity in the Piceance is principally along a west-to-east fairway in the Grand Valley, Parachute, Rulison and Mamm Creek Fields, where the Williams Fork and lower Rollins, Cozzette and Corcoran sections of the Mesaverde lend themselves to drilling wells on 10-acre subsurface spacing.
At present, drilling multiple directional wells from single pads and crafting more advanced completion technologies are allowing operators like EnCana and Williams to achieve average per-well recoveries of 1.2-to 1.4 billion cubic feet.
-With files from Oil and Gas Investor
Resource estimates
"The USGS assessed undiscovered conventional oil and gas and continuous (unconventional) oil and gas, including coal-bed gas for the Piceance Basin. The USGS estimated a mean of 21 trillion cubic feet of gas (TCFG), a mean of 60 million barrels of oil (MMBO), and a mean of 43 million barrels of natural gas liquids (MMBNGL) in five Total Petroleum Systems. Nearly all of the undiscovered gas resource is continuous (unconventional) rather than conventional. Of the 21 TCFG, 13 TCFG is estimated to be in the Mesaverde Total Petroleum System, and seven TCFG is in the Mancos/Mowry Total Petroleum System. The Ferron/Wasatch Plateau Total Petroleum System and Mesaverde Total Petroleum System are estimated to contain 2.3 TCFG of coal-bed gas. The Phosphoria and Green River Total Petroleum Systems contain the balance of the undiscovered gas resource."
Source: USGS fact sheet
The Piceance Basin is asymmetric, with steep beds on the eastern boundary and gentle dips on the Western edge. The primary gas producing formations are the Wasatch, Lower Fort Union and Mesaverde. These are overlain by the Green River Formation, up to 3,000 feet deep in the centre of the basin to only a few feet thick in the Southwest.
The Mesaverde is of Cretaceous age and consists of sandstones, mudstones and coal. While the natural fractures in the formation have enabled the production of natural gas by conventional means for many years, new technologies and favourable economics now make production from the tight sands technically and economically viable. Hence, depending on here a well is drilled and how it is completed in the Mesaverde, it may be conventional gas, tight sands, or a coalbed methane well.
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