Browsing by Subject "Piceance Basin"
Now showing 1 - 5 of 5
- Results Per Page
- Sort Options
Item Coalbed Methane Potential of the Greater Green River, Piceance, Powder River and Raton Basins(1991) Tyler, Roger; Ambrose, William A.  ; Scott, Andrew R.; Kaiser, W. R.Coalbed methane potential of the Greater Green River, Piceance, Powder River, and Raton Basins was evaluated in the context of geologic and hydrologic characteristics identified in the San Juan Basin, the nation's leading coalbed methane producing basin. The major comparative criteria were (1) coalbed methane resources, (2) geologic and hydrologic factors that predict areas of high gas producibility and high coalbed reservoir permeability, and (3) coalbed thermal maturity. These technical criteria were expanded to include structure, depositional systems, and database and then combined with economic criteria (production, industry activity, and pipeline availability) to evaluate the coalbed methane potential of the basins. The Greater Green River and Piceance Basins have primary potential to make a significant near-term contribution to the nation's gas supply. These basins have large gas resources, high-rank coals, high gas contents, and established coalbed methane production. The Greater Green River Basin has numerous coalbed methane targets, good coal-seam permeability, and extensive hydrologic areas favorable for production. The Powder River and Raton Basins were judged to have secondary potential. Coal beds in the Powder River Basin are thermally immature and produce large volumes of water; the Raton Basin has a poor database and has no gas pipeline infrastructure. Low production and minimal industry activity further limit the near-term potential of the Raton Basin. However, if economic criteria are discounted and only major technical criteria are considered, the Greater Green River and Raton Basins are assigned primary potential. The Raton Basin's shallow, thermally mature coal beds of good permeability are attractive coalbed methane targets, but low coal-seam permeability limits the coalbed methane potential of the Piceance Basin.Item Geologic and Hydrologic Controls Critical to Coalbed Methane Producibilty and Resource Assessment: Williams Fork Formation, Piceance Basin, NorthWest Colorado(1996) Tyler, Roger; Scott, Andrew R.; Kaiser, W. R.As predicted from an evolving coalbed methane producibility model, extraordinary coal gas production is precluded in the Piceance Basin by the absence of reservoir continuity and dynamic groundwater flow. The best potential for coal gas production may lie in conventional traps basinward of where outcrop and subsurface coals are in good reservoir and hydraulic communication and in areas of vertical flow potential. Synergism between tectonic and structural setting, depositional systems and coal distribution, coal rank, gas content, permeability, and hydrodynamics are controls critical to coalbed methane producibility. Within the genetically defined, coal-bearing Upper Cretaceous Williams Fork Formation, net coal thickness is typically 80 to 120 ft and is thickest in a north-south belt, behind west-east prograding shoreline sequences. Depositional setting and thrust faults cause coals along the Grand Hogback and in the subsurface to be in modest to poor reservoir and hydraulic communication, restricting meteoric groundwater recharge and flow basinward. Face cleats of Late Cretaceous age strike east-northeast and west-northwest in the southern and northern parts of the basin, respectively, normal to the Hogback thrust front. Parallelism between face-cleat strike and present-day maximum horizontal stress direction may enhance coal permeability in the north. In the Grand Valley/Parachute/Rulison and White River/Pinyon Ridge areas, structure and sandstone development control gas production from Cameo-Wheeler-Fairfield coals and/or sandstones. The most productive wells are on anticlines and structural terraces or correspond to sandstone development, reflecting fracture-enhanced permeability. Total subsurface coal resources are estimated to be 289 billion tons (262 Bt), whereas coal gas resources are approximately 99 Tcf (3.09 Tm^3), although coal gas estimates range between 80 (2.49 Tm^3) and 136 Tcf (4.24 Tm^3), depending on the calculation method. Based on completion data provided by operators, it appears that production from coalbed methane reservoirs can meet minimum economic requirements in the Grand Valley, Rulison, and Pinyon Ridge fields. To achieve high gas contents or fully gas-saturated coals for consequent high productivity in the Piceance Basin, research, exploration, and development for migrated conventionally and hydrodynamically trapped gases, in situ generated secondary biogenic gases, and solution gases will be required.Item Geologic Characterization and Coalbed Methane Occurrence: Williams Fork Formation, Piceance Basin, Northwest Colorado(1995) Tyler, Roger; Kaiser, W. R.; McMurry, Ronald G.The coal-bearing Upper Cretaceous Williams Fork Formation, 1,200 to 2,500 ft thick, is operationally defined on the basis of correlation with the Sand Wash Basin. Net coal thickness is typically 80 to 120 ft and is thickest in a north-south belt west of the Divide Creek Anticline. Depositional setting and thrust faults cause coals along the Grand Hogback and in the subsurface to be in modest to poor hydraulic communication. Thus, meteoric recharge and flow basinward is restricted. Face cleats of Late Cretaceous age strike east-northeast and west-northwest in the southern and northern parts of the basin, respectively, normal to the Hogback thrust front. Parallelism between face-cleat strike and present-day maximum horizontal stress direction may enhance coal permeability in the north. Lineament azimuths lie between 20 to 40° and 280 to 310°; they are not a reliable indicator of subsurface fracture attributes nor of gas production. In the Grand Valley/Rulison and White River/Pinyon Ridge areas, structure and sandstone development control gas production from Cameo coals and/or sandstones. The most productive wells are on structural terraces and anticlines or correspond to Cameo sandstone development, reflecting fracture-enhanced permeability. As predicted, from an evolving coalbed methane producibility model, extraordinary coal-gas production is precluded by the absence of dynamic groundwater flow. The best potential for coal-gas production may lie in conventional traps basinward of where outcrop and subsurface coals are in good hydraulic communication.Item Hydraulic fracture optimization using hydraulic fracture and reservoir modeling in the Piceance Basin, Colorado(2012-08) Reynolds, Harris Allen; Olson, Jon E.; Laubach, SteveHydraulic fracturing is an important stimulation method for producing unconventional gas reserves. Natural fractures are present in many low-permeability gas environments and often provide important production pathways for natural gas. The production benefit from natural fractures can be immense, but it is difficult to quantify. The Mesaverde Group in the Piceance Basin in Colorado is a gas producing reservoir that has low matrix permeability but is also highly naturally fractured. Wells in the Piceance Basin are hydraulically fractured, so the production enhancements due to natural fracturing and hydraulic fracturing are difficult to decouple. In this thesis, dipole sonic logs were used to quantify geomechanical properties by combining stress equations with critically-stressed faulting theory. The properties derived from this log-based evaluation were used to numerically model hydraulic fracture treatments that had previously been pumped in the basin. The results from these hydraulic fracture models, in addition to the log-derived reservoir properties were used to develop reservoir models. Several methods for simulating the reservoir were compared and evaluated, including layer cake models, geostatistical models, and models simulating the fracture treatment using water injection. The results from the reservoir models were compared to actual production data to quantify the effect of both hydraulic fractures and natural fractures on production. This modeling also provided a framework upon which completion techniques were economically evaluated.Item Shoreline architecture and sequence stratigraphy of Campanian Iles clastic wedge, Piceance Basin, CO : influence of Laramide movements in Western Interior Seaway(2012-08) Karaman, Ozge; Steel, Ronald J.; Fisher, William L.; Olariu, CornelThe Campanian Iles Formation of the Mesaverde Group in northwestern Colorado contains a stacked series of some 11 shoreline sequences that form clastic wedges extending east and southeastwards from the Sevier orogenic belt to the Western Interior Seaway. Iles Formation shorelines and their alluvial and coastal plain equivalents (Neslen Formation, Trail and Rusty members of the Ericson Formation) are well exposed from Utah and from southern Wyoming into northwestern Colorado. The Iles Clastic Wedge was examined in the subsurface Piceance Basin and at outcrops in Meeker and south of Rangely, NW Colorado. The clastic wedge contains low-accommodation regressive-transgressive sequences (8-39 m thick) of Loyd Sandstones, Sego Sandstone, Corcoran Member, and Cozzette Member and their updip-equivalent Neslen Formation strata. Facies associations of the sandstone succession indicate storm-wave dominated coasts that transition seaward into offshore/prodelta mudstones with thin-bedded sandstones and extend landward into tidal/fluvial channels and coal-bearing strata; facies associations also indicate interdeltaic coastal embayments with moderate tidal influence. 14, 75-km-long Piceance Basin transects (dip and strike oriented) makes it possible to evaluate coastline variability, and the progressive southeasterly pinchout of the 11 coastline tongues within the larger Iles Clastic Wedge. The thickness and great updip-downdip extent of the Iles stratigraphic sequences (compared to the underlying Blackhawk or overlying Rollins sequences) support previous observations of a low accommodation setting during this time. It has been suggested that this low accommodation was caused by combined effects of embryonic Laramide uplifts and Sevier subsidence across the region. Uplift or greatly reduced subsidence across the Western Interior Seaway would have caused an increase in coastal embayments as well as generally accelerated coastal regressions and transgressions in this 3.3 My interval.