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Research about Anadarko Basin

Source-linked reports with geographic coverage including Anadarko Basin.

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Petroleum systems and assessment of undiscovered oil and gas in the Anadarko Basin Province, Colorado, Kansas, Oklahoma, and Texas: USGS Province 58

This publication provides research results and related data in support of the U.S. Geological Survey assessment of the undiscovered oil and gas resource potential of the Anadarko Basin Province of western Oklahoma and Kansas, northern Texas, and southeastern Colorado. This province area includes the Las Animas arch of southeastern Colorado, part of the Palo Duro Basin of Texas, and the Anadarko Basin. Results of the geologic analysis and resource assessment are based on the geologic elements of each defined total petroleum system, including hydrocarbon source rocks (source-rock maturation, hydrocarbon generation and migration), reservoir rocks (sequence stratigraphic and petrophysical properties), hydrocarbon traps (trapping mechanisms and timing), and seals. Using this geologic framework, the U.S. Geological Survey defined 2 total petroleum systems, the Woodford Composite total petroleum system and Pennsylvanian Composite total petroleum system and 12 included assessment units, and quantitatively estimated the undiscovered oil and gas resources within these conventional and continuous (unconventional) AUs. The 13 chapters included in U.S. Geological Survey Digital Data Series DDS–69–EE cover topics that range from the oil and gas resource assessment results (chapter 1 and 5–7), to geological, geochemical, and geophysical research across the province (chapters 3–11), tabular data and graphs in support of the assessment (chapter 12), and data releases of zmap-format grid files that were used to build petroleum system models and a standalone three-dimensional geologic model (chapter 13).

Colorado, Kansas, Oklahoma, Texas

Maps showing petroleum exploration intensity and production in major Cambrian to Ordovician reservoir rocks in the Anadarko Basin

The Anadarko basin is a large, deep, two-stage Paleozoic basin (Feinstein, 1981) that is petroleum rich and generally well explored. The Anadarko basin province, a geogrphic area used here mostly for the convenience of mapping and data management, is defined by political boundaries that include the Anadarko basin proper. The boundaries of the province are identical to those used by the U.S. Geological Survey (USGS) in the 1995 National Assessment of United Stated Oil and Gas Resources. The data in this report, also identical to those used in the national assessment, are from several computerized data bases including Nehring Research Group (NRG) Associates Inc., Significant Oil and Gas Fields of the United States (1992); Petroleum Information (PI), Inc., Well History Control System (1991); and Petroleum Information (PI), Inc., Petro-ROM: Production data on CD-ROM (1993). Although generated mostly in response to the national assessment, the data presented here arc grouped differently and arc displayed and described in greater detail. In addition, the stratigraphic sequences discussed may not necessarily correlate with the "plays" of the 1995 national assessment. This report uses computer-generated maps to show drilling intensity, producing wells, major fields, and other geologic information relevant to petroleum exploration and production in the lower Paleozoic part of the Anadarko basin province as defined for the U.S. Geological Survey's 1995 national petroleum assessment. Hydrocarbon accumulations must meet a minimum standard of 1 million barrels of oil (MMBO) or 6 billion cubic feet of gas (BCFG) estimated ultimate recovery to be included in this report as a major field or revoir. Mapped strata in this report include the Upper Cambrian to Lower Ordovician Arbuckle and Low Ordovician Ellenburger Groups, the Middle Ordovician Simpson Group, and the Middle to Upper Ordovician Viola Group.

Colorado, Kansas, Oklahoma, Texas

Thermal maturity of the Anadarko Basin

Levels of thermal maturity are estimated for Paleozoic strata in five areas of the central Anadarko basin for times between the Paleozoic and the present, and depths of the oil window are plotted as a function of geologic time. Mean surface temperature assumed here for calculating Lopatin's time-temperature index of thermal maturity (TTl) in the central Anadarko basin declines from 80°F (27°C) to 60°F (16°C) from early Paleozoic time to the present. Shallow-water carbonates and lower paleolatitudes suggest warmer climates in the Paleozoic for this area. The geothermal gradient is assumed to equal 4.0°F/100 ft (7.3°C/100 m) in the Late Cambrian and to decay over a 100-m.y. period to the present regional gradient of 1.3°F/100 ft (2.4°C/100 m). Initial basin formation was caused by crustal thinning. Accumulation of thick Pennsylvanian sediments in a foreland-style basin dominated by vertical lithospheric flexure represents a second major period of subsidence. An elevated geothermal gradient during this time is not assumed for TTl calculations, because mathematical models suggest time-invariant heat flows in such basins. TTl computations based on these assumptions indicate that oil could have been generated in the ancestral Anadarko basin >350 m.y. ago. By the end of the Pennsylvanian, significant volumes of kerogen were in the oil window (and perhaps beyond), and significant volumes have remained in the oil window up to the present day. These circumstances may partially explain the unusual richness of the Anadarko basin as a Paleozoic hydrocarbon province.

Oklahoma

Characterization and origin of natural gases of the Anadarko Basin

Natural-gas production in the Anadarko basin is from three geographically separated areas that can be differentiated by age of reservoir and by inferred nature of thermal origin of the gases. In the central basin, nonassociated gases are produced mainly from Upper Mississippian and Pennsylvanian sandstones. Gases become isotopically heavier (&delta; 13 C 1 values range from -49.8 to -33.2 ppt) and chemically drier (C 1 /C 1&ndash;5 values range from 0.74 to 0.99) with increasing level of thermal maturity. Gas samples are from depths as much as 21,600 ft. Gases were generated mainly from interbedded shales with type-III kerogen during the mature and postmature stages of hydrocarbon generation. Deviations from the trend are due to mixing and migration of gases generated at different levels of thermal maturity over the past 250 m.y. In the giant Panhandle-Hugoton field, nonassociated gases are generally produced from Permian carbonates at depths <3,000 ft. Gases display little compositional variation &delta; 13 C 1 values range from -46.4 to -39.9 ppt, C 1 /C 1&ndash;5 values range from 0.69 to 0.96). Because organic-rich, mature source rocks are not present in the area, gases probably were generated in the central basin from Pennsylvanian or older source rocks during the mature stage of hydrocarbon generation. This implies migration over distances as much as several hundred miles. In the Sooner trend, associated gases are produced from Silurian, Devonian, and Mississippian carbonates at depths as great as 9,600 ft and were generated from type-II kerogen during the mature stage of hydrocarbon generation. Associated oil correlates with extracts of the Upper Devonian and Lower Mississippian Woodford Shale. Gases are isotopically lighter (&delta; 13 C 1 values of -47.3 to -40.6 ppt) and chemically wetter (C 1 /C 1&ndash;5 values of 0.67 to 0.99) than those derived from type-III kerogen at an equivalent level of thermal maturity.

Oklahoma

Geochemistry of oils and hydrocarbon source rocks, greater Anadarko Basin: evidence for multiple sources of oils and long-distance oil migration

Organic geochemical analyses of 104 crude oils and 190 core samples of dark-colored shales from the greater Anadarko basin show three major oil types which generally correlate with reservoir age and source-rock age. Analyses include C 3 -C 30 whole-oil gas chromatography, C 10+ saturated-hydrocarbon-fraction gas chromatography, and carbon stable isotopes (ppt relative to PDB) of saturated (sat) and aromatic (arom) hydrocarbon fractions. Three samples from Middle Ordovician Simpson Group reservoirs are "typical" Ordovician oils (type 1), having strong odd-carbon predominance in the C 13 to C 19 n-alkanes, containing little or no acyclic isoprenoids, an &delta; 13 C values of -33.9 ppt (sat) and -33.7 ppt (arom). Oils from Silurian to Devonian and Mississippian reservoirs (type 2) show little or no odd-carbon predominance in the n-alkanes, a regular decrease in abundance of n-alkanes with increasing carbon number, pristane/phytane ratios (pr/ph) of 1.1 to 1.5, and &delta; 13 C values of -30.6 ppt (sat) and -30.1 ppt (arom). Oils in Pennsylvanian reservoirs (type 3) have the greatest amounts of C 15+ hydrocarbons, are isotopically heavy (-27.5 ppt [sat] and -26.4 ppt [arom]), have methyl-cyclohexane as the most abundant hydrocarbon, and have pr/ph values from 2.0 to 0.9. Oils from the Kansas shelf area of the Anadarko basin are similar to the Anadarko oil types except that they have only traces of toluene and no detectable benzene. The relative abundance of toluene in the C 7 hydrocarbons systematically decreases with distance from the depocenter of the basin. The aromatic compounds are removed by water-washing, and hence could have been lost by contact with progressively greater amounts of formation water during long-distance migration. The lack of thermally mature source rocks in southern and central Kansas supports this hypothesis.

Oklahoma

Structural evolution of the southeastern portion of the Anadarko Basin region

Field investigations in the Lake Classen-Turner Falls, Oklahoma, area of the northern Arbuckle anticline, on the southeastern margin of the Anadarko basin, indicate that transpressional (oblique compressional) deformation of Late Pennsylvanian age dominated the structural development of this area. The Arbuckle anticline is detached along the NW -trending, SW -dipping, left-reverse Arbuckle fault and is thrust obliquely onto the margin of the Tishomingo block to the east. Paleostress analysis of slip lines on mesoscopic faults along the northeastern limb of the Arbuckle anticline, associated in style and geometry with oblique Arbuckle thrusting, indicates compression directed N. 35-60° E.

Oklahoma

Anadarko Basin conodont studies

Preliminary analysis of early Paleozoic conodonts from the subsurface within and adjacent to the Anadarko basin demonstrates their utility in stratigraphic and thermal evolution studies in the basin. More than 100 samples from 30 drill holes produced conodonts that can be correlated with faunas known from rock sequences exposed along the southern flanks of the basin. For the Middle Ordovician to Devonian, extant biozonations and/or recent published literature based on Oklahoma surface sections allow good biostratigraphic correlation into the subsurface and often allow testing of physical correlations. In contrast, conodonts from the Arbuckle Group (Lower to Middle Ordovician) are less well known. Faunas from the upper half of the group are documented only in unpublished theses, and published faunas are in need of restudy and revision. However, this limited information, along with work in progress in Oklahoma and data from carbonate platform facies elsewhere in North America, still permit correlations into the subsurface with the promise of increasingly improved resolution.

Oklahoma

Diagenesis of hydrocarbon-bearing rocks in the Middle Ordovician Simpson Group, southeastern Anadarko Basin, Oklahoma

Quartzarenites and subarkoses in the Middle Ordovician Simpson Group in the Gulf Costello No. 1 and Sunray-DX Parker No. 1 Mazur wells, southeastern Anadarko basin, have undergone a complex diagenetic and petroleum-migration history. During early burial, petroleum migrated locally through sandstones; patches of bitumen in calcite and bitumen-lined quartz overgrowths containing oil-bearing inclusions reflect the introduction of petroleum-bearing fluids at shallow depths. Stable-isotope data reveal that early calcite precipitated at near-surface temperatures from fluids dominated by marine carbon. At moderate to deep burial, calcite dissolution, followed by ferroan-dolomite and clay-mineral precipitation, occurred at about the same time as the rocks reached levels of thermal maturity sufficient for the generation of hydrocarbons. Maximum paleotemperatures during deep burial are estimated from maturation models to have reached 250°F in the Costello well and 300°F in the Mazur well. Maturation-derived temperatures in the Costello well are consistent with preliminary homogenization temperatures (210-250°F) for oil inclusions along microscopic healed fractures that formed during deep burial, thus supporting an Early to Middle Pennsylvanian timing for the generation and migration of late-stage hydrocarbons. The early petroleum phase, emplaced while the rocks were at shallow burial depths, migrated from mature source rocks deeper in the basin.

Oklahoma

Relationship of clay-mineral diagenesis to temperature, age, and hydrocarbon generation&ndash;an example from the Anadarko Basin, Oklahoma

Randomly interstratified illite/smectite (I/S) is present in Springeran and Morrowan rocks (Late Mississippian and Early Pennsylvanian) of the Anadarko basin, Oklahoma, at present-day depths <2,750 m, but disappears at depths of 2,750-3,050 m. Only ordered I/S is found in samples below 3,050 m. The work reported here relates the diagenesis of I/S to burial history and oil generation in the Anadarko basin and tests the dependence of the smectite-to-illite reaction on temperature and time. Published temperature models of clay diagenesis suggest that, for Tertiary and Cretaceous rocks, the transition from randomly interstratified I/S to ordered I/S occurs at 100-110°C. Burial reconstructions for the Anadarko basin indicate that maximum temperatures of 100-110°C correspond to present-day burial depths between 2,700 and 3,100 m. These independently calculated depths for the 100-110°C isotherm match the depths at which randomly interstratified I/S is observed to disappear in Morrowan-Springeran rocks. Thus, random I/S disappears at the same temperature in rocks that differ in age by some 300 m.y. Although the extent of the smectite-to-illite reaction is controlled by kinetics, and effects of time are apparent in laboratory experiments and short-lived geologic systems, the results of this study suggest that time plays a secondary role in long-term diagenetic settings.

Oklahoma