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74-1411: Oil and gas in Province 045 are produced from carbonate and clastic rock reservoirs ranging in age from the Ordovician to the Permian . The 1995 USGS Assessment of undiscovered, technically recoverable oil and gas identified six conventional plays in Province 045, which are listed below in Table 1: One continuous unconventional play, the " Mississippian Barnett Shale " (4503), was also considered. The cumulative mean of undiscovered resource for conventional plays was: 381 million barrels (60.6 × 10 ^  m) of oil, 103.6 million barrels (16.47 × 10 ^  m) of natural gas liquids , 479 billion cubic feet (13.6 × 10 ^  m) associated gas, and 1,029 billion cubic feet (29.1 × 10 ^  m) non-associated gas. Notes: 1. Assessment unit number also indicates time span of stratigraphic units. The United States Geological Survey's assessment of undiscovered conventional oil and gas and undiscovered continuous (unconventional) gas within Province 045 resulted in estimated means of 26.7 trillion cubic feet (760 × 10 ^  m) (Tcf) of undiscovered natural gas, 98.5 million barrels (15.66 × 10 ^  m) of undiscovered oil, and

148-684: A barrel of crude into various products results in an increase to 45 US gallons (37 imp gal; 170 L). In the 18th and 19th centuries, whale oil was commonly used for lamps, which was replaced with natural gas and then electricity. Crude oil can be refined into a wide variety of component hydrocarbons . Petrochemicals are the refined components of crude oil and the chemical products made from them. They are used as detergents , fertilizers , medicines , paints , plastics , synthetic fibers , and synthetic rubber . Organic oils are another important chemical feedstock, especially in green chemistry . Stratigraphic Stratigraphy

222-510: A combination of facies and depositional topography , erosion, updip pinchout of facies, and diagenetically controlled enhanced-permeability and porosity zones. A good example of a carbonate stratigraphic trap is the pinnacle reef traps of the Chappel Limestone, where local porous grainstone and packstone are restricted to isolated buildups or reef clusters on the eroded Ellenburger Group. Chappel pinnacle reefs are draped and sealed by

296-520: A mean of 1.1 billion barrels (170 × 10 ^  m) of undiscovered natural gas liquids. Nearly all of the undiscovered gas resource (98%, 2.62 × 10 cu ft or 7.4 × 10 m) is considered to be in continuous accumulations of nonassociated gas trapped in strata of two of the three Mississippian-age Barnett Shale Assessment Units (AUs) - the Greater Newark East Frac-Barrier Continuous Barnett Shale Gas AU and

370-407: A religious medium. It is often considered a spiritually purifying agent and is used for anointing purposes. As a particular example, holy anointing oil has been an important ritual liquid for Judaism and Christianity . Oils have been consumed since ancient times. Oils hold lots of fats and medical properties. A good example is olive oil. Olive oil holds a lot of fats within it which is why it

444-436: A section. The samples are analyzed to determine their detrital remanent magnetism (DRM), that is, the polarity of Earth's magnetic field at the time a stratum was deposited. For sedimentary rocks this is possible because, as they fall through the water column, very fine-grained magnetic minerals (< 17  μm ) behave like tiny compasses , orienting themselves with Earth's magnetic field . Upon burial, that orientation

518-416: Is a branch of geology concerned with the study of rock layers ( strata ) and layering (stratification). It is primarily used in the study of sedimentary and layered volcanic rocks . Stratigraphy has three related subfields: lithostratigraphy (lithologic stratigraphy), biostratigraphy (biologic stratigraphy), and chronostratigraphy (stratigraphy by age). Catholic priest Nicholas Steno established

592-576: Is a peripheral Paleozoic foreland basin with about 12,000 feet (3,700 m) of strata preserved in its deepest northeast portion adjacent to the Muenster Arch and Ouachita structural belt. The basin resembles other basins of the Ouachita structural belt, such as the Black Warrior, Arkoma, Val Verde , and Marfa Basins that formed in front of the advancing Ouachita structural belt as it was thrust onto

666-431: Is also commonly used to delineate the nature and extent of hydrocarbon -bearing reservoir rocks, seals, and traps of petroleum geology . Chronostratigraphy is the branch of stratigraphy that places an absolute age, rather than a relative age on rock strata . The branch is concerned with deriving geochronological data for rock units, both directly and inferentially, so that a sequence of time-relative events that created

740-689: Is any nonpolar chemical substance that is composed primarily of hydrocarbons and is hydrophobic (does not mix with water ) and lipophilic (mixes with other oils). Oils are usually flammable and surface active . Most oils are unsaturated lipids that are liquid at room temperature. The general definition of oil includes classes of chemical compounds that may be otherwise unrelated in structure, properties, and uses. Oils may be animal , vegetable , or petrochemical in origin, and may be volatile or non-volatile. They are used for food (e.g., olive oil ), fuel (e.g., heating oil ), medical purposes (e.g., mineral oil ), lubrication (e.g. motor oil ), and

814-535: Is associated with gas production in Wise County , Barnett source rock maturity is generally 1.1% Ro or greater. The zone of wet gas generation is in the 1.1-1.4% Ro range, whereas the primary zone of dry gas generation (main gas window) begins at a Ro of 1.4%. Thermal maturity of Barnett Shale can also be derived from TOC and Rock-Eval (Tmax) measurements. Although Tmax is not very reliable for high maturity kerogens due to poor pyrolysis peak yields and peak shape,

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888-402: Is converted to hydrocarbons. Thus, its original TOC was about 7.0% with an initial estimated potential of 5.64% by volume. Any oil generated would be expelled into shallow (or deeper) horizons as in the west and north, or cracked to gas where measured vitrinite reflectance is above 1.1% Ro. The Barnett Shale is thermally mature for hydrocarbon generation over most of its area. Barnett source rock

962-558: Is derived from the Mitcham #1 well in Brown County where TOC is 4.2% and hydrocarbon potential is 3.37% by volume. Using these data we can determine TOC values will decrease 36% during maturation from the immature stage to the gas-generation window. Samples from the T. P. Simms well in the Newark East gas-producing area have average TOC values of 4.5%, but greater than 90% of the organic matter

1036-534: Is due to physical contrasts in rock type ( lithology ). This variation can occur vertically as layering (bedding), or laterally, and reflects changes in environments of deposition (known as facies change). These variations provide a lithostratigraphy or lithologic stratigraphy of the rock unit. Key concepts in stratigraphy involve understanding how certain geometric relationships between rock layers arise and what these geometries imply about their original depositional environment. The basic concept in stratigraphy, called

1110-1030: Is estimated to contain a mean of 409.2 billion cubic feet (11.59 × 10 ^  m) of conventional gas, or about 88% of all undiscovered conventional gas, and about 64.6 million barrels (10.27 × 10 ^  m) of conventional oil, or about 65% of all undiscovered oil in Province 045. Continuous-type accumulations include fractured shale and fractured limestone oil and gas, basin-centered gas, coal bed gas, and tight reservoir gas. They typically cover large areas, have source rocks in close association with these unconventional reservoir rocks, and are mostly gas (and in some cases oil) charged throughout their extent. Continuous accumulations commonly have transition zones that grade into more conventional accumulations. The Fort Worth Basin and Bend Arch lie entirely within North Central Texas covering an area of 54,000 square miles (140,000 km). The southern and eastern boundaries are defined by county lines that generally follow

1184-536: Is from Mississippian fractured Barnett Shale and early Pennsylvanian (Morrowan) fractured Marble Falls Limestone. Conglomerate of the Pennsylvanian Bend Group is the main producing reservoir in the Boonsville Bend Field with cumulative production through 2001 exceeding 3 trillion cubic feet (85 × 10 ^  m) of gas. Oil sourced from Barnett Shale is produced from numerous reservoir rocks in

1258-506: Is mostly from clastic reservoirs. The sedimentary section in the Fort Worth Basin is underlain by Precambrian granite and diorite . Cambrian rocks include granite conglomerate, sandstones, and shale that are overlain by marine carbonate rocks and shale. No production has been reported from Cambrian rocks. The Silurian , Devonian , Jurassic , and Triassic are absent in the Fort Worth Basin. From Cambrian through Mississippian time,

1332-1202: Is no evidence that NASA has used whale oil. Some oils burn in liquid or aerosol form, generating light , and heat which can be used directly or converted into other forms of energy such as electricity or mechanical work. In order to obtain many fuel oils, crude oil is pumped from the ground and is shipped via oil tanker or a pipeline to an oil refinery . There, it is converted from crude oil to diesel fuel (petrodiesel), ethane (and other short-chain alkanes ), fuel oils (heaviest of commercial fuels, used in ships/furnaces), gasoline (petrol), jet fuel , kerosene , benzene (historically), and liquefied petroleum gas . A 42-US-gallon (35 imp gal; 160 L) barrel of crude oil produces approximately 10 US gallons (8.3 imp gal; 38 L) of diesel, 4 US gallons (3.3 imp gal; 15 L) of jet fuel, 19 US gallons (16 imp gal; 72 L) of gasoline, 7 US gallons (5.8 imp gal; 26 L) of other products, 3 US gallons (2.5 imp gal; 11 L) split between heavy fuel oil and liquified petroleum gases, and 2 US gallons (1.7 imp gal; 7.6 L) of heating oil. The total production of

1406-622: Is preferred for lubricating clocks, because it does not evaporate, leaving dust, although its use was banned in the US in 1980. It is a long-running myth that spermaceti from whales has still been used in NASA projects such as the Hubble Space Telescope and the Voyager probe because of its extremely low freezing temperature. Spermaceti is not actually an oil, but a mixture mostly of wax esters, and there

1480-674: Is presently in the oil-generation window along the north and west parts of the province, and in the gas window on the east half of the Barnett-Paleozoic TPS. Expulsion of high-quality oil from the Barnett was episodic and began at low (Ro = 0.6%) thermal maturity. Thirty-two oils from Wise and Jack Counties were analyzed to determine the characteristics of the generating source rock. API gravity and sulfur content were integrated with high-resolution gas chromatography (GC) and Gas chromatography-mass spectrometry (GCMS) analyses. The API gravity of

1554-411: Is preserved. For volcanic rocks, magnetic minerals, which form in the melt, orient themselves with the ambient magnetic field, and are fixed in place upon crystallization of the lava. Oriented paleomagnetic core samples are collected in the field; mudstones , siltstones , and very fine-grained sandstones are the preferred lithologies because the magnetic grains are finer and more likely to orient with

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1628-465: Is remote (and was unknown at the time of its discovery), and because it is obtained in the vicinity of rocks, underground traps, and sands. Mineral oil also refers to several specific distillates of crude oil. Several edible vegetable and animal oils, and also fats , are used for various purposes in cooking and food preparation. In particular, many foods are fried in oil much hotter than boiling water. Oils are also used for flavoring and for modifying

1702-492: Is represented by the egg yolk, and the reef flank debris are represented by the egg white. The inter-reef facies is represented by a black, calcareous, bituminous shale. Where it occurs in Jack County it is typically 30 to 40 feet (9 to 12 meters) thick, and it is synonymous with the calcareous basal shale member of the Barnett. Consequently, the proximity of a given borehole to a nearby reef complex can be qualitatively estimated by

1776-594: The Ouachita structural front, although a substantial portion of this structural feature is included near Dallas . The north boundary follows the Texas-Oklahoma State line in the east, where the province includes parts of the Sherman Basin and Muenster Arch. In the west, the north boundary follows the north-east county lines of Oklahoma's three southwestern counties (Harmon, Jackson and Tillman Counties), which include

1850-431: The law of superposition , states: in an undeformed stratigraphic sequence, the oldest strata occur at the base of the sequence. Chemostratigraphy studies the changes in the relative proportions of trace elements and isotopes within and between lithologic units. Carbon and oxygen isotope ratios vary with time, and researchers can use those to map subtle changes that occurred in the paleoenvironment. This has led to

1924-547: The natural remanent magnetization (NRM) to reveal the DRM. Following statistical analysis, the results are used to generate a local magnetostratigraphic column that can then be compared against the Global Magnetic Polarity Time Scale. This technique is used to date sequences that generally lack fossils or interbedded igneous rocks. The continuous nature of the sampling means that it is also a powerful technique for

1998-531: The 1995 USGS Assessment was 2 billion barrels (320 × 10 ^  m) of oil, 7.8 trillion cubic feet (220 × 10 ^  m) of gas, and 500 million barrels (79 × 10 ^  m) of natural gas liquids. Cumulative gas production from the Barnett Shale for the first half of 2002 was 94 billion cubic feet (2.7 × 10 ^  m); annual production for 2002 was estimated at 200 billion cubic feet (5.7 × 10 ^  m). The primary source rock of

2072-519: The Atoka, Strawn, and Canyon Formations occurred at this time. These Mid- and Late Pennsylvanian rocks consist mostly of sandstones and conglomerates with fewer and thinner limestone beds. Hydrocarbon shows were first encountered in Province 045 during the mid-nineteenth century while drilling water wells. Sporadic exploration began following the Civil War, and the first commercial oil discoveries occurred in

2146-447: The Barnett Shale subcrop is Ellenburger Group carbonate rocks, is being tested by several operators. The unit's resource potential will be guided by the results of current testing with directional wells and various completion methods to determine optimum completion techniques for gas recovery. Historically, estimated ultimate recoveries (EURs) for Barnett gas wells at NE-F increased with time, as follows: In 2002, Devon Energy reported

2220-482: The Barnett is of higher thermal maturity. Gas production is from hydraulically fractured black siliceous shale. Calorific values of gases from NE-F commonly range between 1,050 and 1,300 BTU. The Barnett's main producing facies is a black, organic-rich siliceous shale with a mean composition of about 45% quartz , 27% clay (mostly illite/ smectite , and illite ), 10% carbonate ( calcite , dolomite , and siderite ), 5% feldspar, 5% pyrite , and 5% TOC. Average porosity in

2294-550: The Bend Arch–Fort Worth Basin is Mississippian Chester-age Barnett Shale, perhaps including the overlying Chesterian Forestburg Formation. The Barnett commonly exhibits an uncommonly high gamma-ray log response. Other potential source rocks of secondary importance are Early Pennsylvanian and include dark fine-grained carbonate rock and shale units within the Marble Falls Limestone and the black shale facies of

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2368-800: The Bend Arch–Fort Worth Basin, including Barnett Shale, Caddo Formation, Canyon Group, Marble Falls Formation, Chappel Limestone, Bend Group, and Ellenburger Group. Seal rocks in the Barnett-Paleozoic TPS are mostly shale units and dense, low permeability carbonate rock that are distributed on both regional and local scales. Although these formations are not considered seal rocks in areas where they are tight and not water wet, they serve as barriers confining hydraulic-induced fracturing ( frac barriers ) and help retain formation pressures during well stimulation. Traps for conventional hydrocarbon accumulations are mostly stratigraphic for carbonate rock reservoirs and both structural and stratigraphic in clastic-rock reservoirs. Stratigraphic traps in carbonate rocks result from

2442-585: The Bend flexure from mid-Ordovician through Early Pennsylvanian time resulted in several unconformities. The Red River Arch and the Muenster Arch also became dominant structural features during the Late Mississippian and Early Pennsylvanian. Hydrocarbon production from Ordovician and Mississippian formations is mostly from carbonate reservoirs, whereas production in the Pennsylvanian through Lower-Permian Wolfcamp)

2516-501: The Extended Continuous Barnett Shale Gas AU (2.62 × 10 cu ft combined). The remaining 467 billion cubic feet (13.2 × 10 ^  m) of undiscovered gas resource in the province is in conventional nonassociated gas accumulations (3586 × 8 billion cu ft or 1.015 × 10 m) and associated/dissolved gas in conventional oil accumulations ( 1084 × 10 billion cu ft or 3.07 × 10 m) . The Barnett-Paleozoic TPS

2590-651: The Fort Worth Basin area was part of a stable cratonic shelf with deposition dominated by carbonates. Ellenburger Group carbonate rocks represent a broad epeiric carbonate platform covering most of Texas and central North America during the Early Ordovician . A pronounced drop in sea level sometime between Late Ordovician and earliest Pennsylvanian time, perhaps related to the broad, mid-North American, mid-Carboniferous unconformity, resulted in prolonged platform exposure. This erosional event removed any Silurian and Devonian rocks that may have been present. The Barnett Shale

2664-630: The Late Mississippian and west tilting in the late Paleozoic which formed the Midland Basin. There is disagreement on the structural history of the Bend Arch. Flippen (1982) suggested it acted as a fulcrum and is a flexure and structural high and that only minor uplift occurred in the area to form an erosional surface on the Chester-age limestones that were deposited directly on top of the Barnett. In contrast, Cloud and Barnes (1942) suggested periodic upwarp of

2738-531: The Smithwick/Atoka Shale. The Barnett Shale was deposited over much of North Central Texas; however, because of post-depositional erosion , the present distribution of Barnett is limited to Province 045. The Barnett/Forestburg Chesterian interval is over 1,000 feet (300 m) thick along the southwest flank of the Muenster Arch. It is eroded in areas along the Red River-Electra and Muenster Arches to

2812-414: The US (e.g., Woodford , Bakken , New Albany , and Chattanooga Formations). These black shales all contain oil-prone organic matter (Type II kerogen ) based on hydrogen indices above 350 milligrams of hydrocarbons per gram of TOC and generate a similar type of high quality oil (low sulfur , >30 API gravity). Although kerogen cracking decomposition is a source of oil and gas from the Barnett Shale,

2886-588: The ambient field during deposition. If the ancient magnetic field were oriented similar to today's field ( North Magnetic Pole near the North Rotational Pole ), the strata would retain a normal polarity. If the data indicate that the North Magnetic Pole were near the South Rotational Pole , the strata would exhibit reversed polarity. Results of the individual samples are analyzed by removing

2960-573: The commercial hydrocarbons consist of oil in Pennsylvanian reservoirs. Province 045 is among the more active drilling areas during the resurgence of domestic drilling, which began after the OPEC oil embargo in 1973. It has consistently appeared on the list of the ten most active provinces in terms of wells completed and footage drilled. More than 9100 oil wells and 4,520 gas wells were drilled and completed in this area from 1974 to 1980. Cumulative production in Province 045 from conventional reservoirs prior to

3034-427: The degree to which this lower member of the Barnett has been impregnated with calcite. Clastic rocks of provenance similar to the Barnett dominate the Pennsylvanian part of the stratigraphic section in the Bend Arch–Fort Worth Basin. With progressive subsidence of the basin during the Pennsylvanian, the western basin hinge line and carbonate shelf, continued migrating west. Deposition of thick basinal clastic rocks of

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3108-431: The discovery of more fields and production from numerous other reservoirs including Strawn fluvial/deltaic sandstones, Marble Falls carbonate bank limestones, the Barnett siliceous shale, and occasional upper Ellenburger dolomitic limestones. By 1960, the province reached a mature stage of exploration and development as demonstrated by the high density and distribution of well penetrations and productive wells. A majority of

3182-527: The early 1900s. In 1917, discovery of Ranger field stimulated one of the largest exploration and development "booms" in Texas. The Ranger field produces from the Atoka-Bend formation, a sandstone-conglomerate reservoir that directly overlies the Barnett formation. Operators drilled more than 1,000 wildcats in and around the Fort Worth Basin attempting to duplicate the success of Ranger. These wildcat efforts resulted in

3256-630: The east portion is an area that includes the Eastern Shelf and Concho Arch, collectively known as the Concho Platform . The Mineral Wells fault runs northeast-southwest through Palo Pinto , Parker, Wise, and Denton Counties and joins with the Newark East fault system. The fault system bisects the Newark East Field (NE-F) creating a zone of poor production in Barnett Shale gas reservoirs. Several faults that cut basement and lower Paleozoic rocks in

3330-896: The excess grime and creating a layer where new grime could form but be easily washed off in the water as oil is hydrophobic. Fish oils hold the omega-3 fatty acid. This fatty acid helps with inflammation and reduces fat in the bloodstream.   Color pigments are easily suspended in oil, making it suitable as a supporting medium for paints . The oldest known extant oil paintings date from 650 AD. Oils are used as coolants in oil cooling , for instance in electric transformers . Heat transfer oils are used both as coolants (see oil cooling ), for heating (e.g. in oil heaters ) and in other applications of heat transfer. Given that they are non-polar, oils do not easily adhere to other substances. This makes them useful as lubricants for various engineering purposes. Mineral oils are more commonly used as machine lubricants than biological oils are. Whale oil

3404-430: The extent of kerogen transformation can be utilized. For example, Barnett Shale having a 4.5% TOC and a hydrogen index of less than 100 is in the wet or dry gas windows with equivalent Ro values greater than 1.1% TOC. In contrast, low maturity Barnett Shale from Lampasas County outcrops have initial TOC values averaging about 12% with hydrocarbon potentials averaging 9.85% by volume. A good average value for Barnett Shale

3478-512: The gap may be due to removal by erosion, in which case it may be called a stratigraphic vacuity. It is called a hiatus because deposition was on hold for a period of time. A physical gap may represent both a period of non-deposition and a period of erosion. A geologic fault may cause the appearance of a hiatus. Magnetostratigraphy is a chronostratigraphic technique used to date sedimentary and volcanic sequences. The method works by collecting oriented samples at measured intervals throughout

3552-517: The gas generation window is along a trend sub-parallel to the Ouachita thrust front. Jarvie (2001) reported the British Thermal Unit (BTU) content of Barnett gas is directly proportional to Ro levels. Reservoir rocks include clastic and carbonate rocks ranging in age from Ordovician to Early Permian. Most production from conventional reservoirs is from Pennsylvanian rocks, whereas the only recognized production from unconventional accumulations

3626-542: The manufacture of many types of paints, plastics, and other materials. Specially prepared oils are used in some religious ceremonies and rituals as purifying agents. First attested in English 1176, the word oil comes from Old French oile , from Latin oleum , which in turn comes from the Greek ἔλαιον ( elaion ), "olive oil, oil" and that from ἐλαία ( elaia ), " olive tree", "olive fruit". The earliest attested forms of

3700-457: The margin of North America . Thrusting occurred during a late Paleozoic episode of plate convergence. The Bend Arch extends north from the Llano Uplift. It is a broad subsurface, north-plunging, positive structure. The arch formed as a hingeline by down-warping of its eastern flank due to subsidence of the Fort Worth Basin during early stages of development of the Ouachita structural belt in

3774-500: The mean EUR for Newark East Barnett gas wells is 1.25 billion cubic feet (35 × 10 ^  m) of gas. The progressive increase in EUR in Barnett wells is the result of improved geologic and engineering concepts that guide development of the Barnett continuous gas play. Moreover, recompletion of wells after about five years of production commonly adds 759 million cubic feet (21.5 × 10 ^  m) to its EUR. Oil An oil

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3848-412: The modern economy. Crude oil originates from ancient fossilized organic materials , such as zooplankton and algae , which geochemical processes convert into oil. The name "mineral oil" is a misnomer , in that minerals are not the source of the oil—ancient plants and animals are. Mineral oil is organic. However, it is classified as "mineral oil" instead of as "organic oil" because its organic origin

3922-591: The north, the Llano uplift to the south where it outcrops, and the easternmost portion of the province where the Barnett laps onto the Eastern Shelf-Concho Platform. Average total organic carbon (TOC) content in the Barnett Shale is about 4% and TOC is as high as 12% in samples from outcrops along the Llano uplift on the south flank of the Fort Worth Basin. It has geochemical characteristics similar to other Devonian-Mississippian black shales found elsewhere in

3996-427: The northern part of the Fort Worth Basin for three-quarters of a century. The Chappel buildups are often referred to as "pinnacle reefs," but that is a misnomer. They may appear as pinnacles on a cross section with an exaggerated vertical scale (see cross sections A-A′ and B-B′ above), but in reality they have almost exactly the same height/width aspect ratio as a fried chicken egg sunny side up. The reef core, of course,

4070-453: The oils ranges from 35° to 62° and sulfur contents are low (<0.2%), which is characteristic of high thermal maturity oils. Biomarkers from GCMS analyses show oils were sourced from marine shale, based on sterane distribution and the presence of diasteranes. Carbon isotopic analyses of saturated and aromatic hydrocarbon fractions support hydrocarbon generation from a single-source unit. In the main gas-producing area of fractured Barnett Shale,

4144-549: The overlying Barnett Shale. Stratigraphic traps in Pennsylvanian Atoka sandstones and conglomerates are mainly pinch outs related to facies changes or erosional truncation. Lesser amounts of high-quality (35-40° API gravity, low sulfur) oil is produced from Barnett Shale in the province's north and western portions where it exhibits low thermal maturity (Ro ≈ 0.6%). Similar quality oils (40-50° API gravity), and condensates associated with gas are produced in Wise County where

4218-507: The overlying Marble Falls Formation (Early Pennsylsvnian), and they have never been formally named, although they are widely referenced in the literature as the "Forestburg Formation." Since the underlying Barnett is generally assumed to be Late Mississippian Chester in age, the superposed Forestburg is occasionally referred to informally as "the Chester Limestones." As the shallow Late Mississippian seas spread southward and westward from

4292-604: The principal source of gas in the Newark East Field is from cracking of oil and bitumen . Low maturation levels in the Barnett Shale at vitrinite reflectance (Ro), estimated at 0.6-0.7%, yield oils of 38° API gravity in Brown County . Oils found in Shackelford , Throckmorton , and Callahan Counties as well, as in Montague County , are derived from Barnett Shale at the middle of the zone of oil generation (oil window) thermal maturities levels (≈0.9% Ro). Although condensate

4366-448: The productive portions is about 6% and matrix permeability is measured in nanodarcies. Three assessment units have been proposed for the Barnett Shale continuous accumulations, each with different geologic and production characteristics: The siliceous nature of the Barnett Shale, and its relation to fracture enhancement in NE-F, was noted by Lancaster. Also, the second assessment unit, where

4440-494: The reefs did not survive to the end of Barnett time; all known Chappel reefs are immediately overlain by the typical Barnett Shale facies except for a very few in central Clay County that have been very deeply breached by pre-Atokan erosion. The reef complexes are subdivisible into three constituent facies: the reef core, the reef flanks, and the inter-reef area. The reef cores are porous enough to serve as stratigraphic traps for oil and gas, and they have yielded excellent production in

4514-437: The rock layers. Strata from widespread locations containing the same fossil fauna and flora are said to be correlatable in time. Biologic stratigraphy was based on William Smith's principle of faunal succession , which predated, and was one of the first and most powerful lines of evidence for, biological evolution . It provides strong evidence for the formation ( speciation ) and extinction of species . The geologic time scale

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4588-480: The rocks formation can be derived. The ultimate aim of chronostratigraphy is to place dates on the sequence of deposition of all rocks within a geological region, and then to every region, and by extension to provide an entire geologic record of the Earth. A gap or missing strata in the geological record of an area is called a stratigraphic hiatus. This may be the result of a halt in the deposition of sediment. Alternatively,

4662-405: The significance of strata or rock layering and the importance of fossil markers for correlating strata; he created the first geologic map of England. Other influential applications of stratigraphy in the early 19th century were by Georges Cuvier and Alexandre Brongniart , who studied the geology of the region around Paris. Variation in rock units, most obviously displayed as visible layering,

4736-687: The south flank of the Wichita Mountains and the Hollis Basin. The western boundary trends north-south along county lines defining the junction with the Permian Basin where part of the eastern shelf of the Permian Basin lies in Province 045. Major structural features include the Muenster and Red River Arches to the north, and the Bend and Lampasas Arches along the central part of Province 045. Along

4810-570: The southern part of the province are identified at the Ordovician Ellenburger Group stratigraphic level. These faults and associated structures formed during development of the Llano Uplift and Fort Worth Basin with faulting ending by the early Missourian. Evolution of the Fort Worth Basin and Bend Arch structures are critical to understanding burial histories and hydrocarbon generation. The asymmetrical, wedge-shaped Fort Worth Basin

4884-406: The specialized field of isotopic stratigraphy. Cyclostratigraphy documents the often cyclic changes in the relative proportions of minerals (particularly carbonates ), grain size, thickness of sediment layers ( varves ) and fossil diversity with time, related to seasonal or longer term changes in palaeoclimates . Biostratigraphy or paleontologic stratigraphy is based on fossil evidence in

4958-496: The subsiding Southern Oklahoma Aulacogen, they inundated an uneven Lower Paleozoic surface and almost immediately initiated the growth of reef-forming organic communities. All of the Mississippian-age reef complexes whose bases have been penetrated by boreholes have been found, without exception, to be resting directly upon the underlying Ordovician rocks. But although reef growth began at the same time as Barnett Shale deposition,

5032-399: The texture of foods (e.g. stir fry ). Cooking oils are derived either from animal fat, as butter , lard and other types, or plant oils from olive , maize , sunflower and many other species. Oils are applied to hair to give it a lustrous look, to prevent tangles and roughness and to stabilize the hair to promote growth. See hair conditioner . Oil has been used throughout history as

5106-429: The theoretical basis for stratigraphy when he introduced the law of superposition , the principle of original horizontality and the principle of lateral continuity in a 1669 work on the fossilization of organic remains in layers of sediment. The first practical large-scale application of stratigraphy was by William Smith in the 1790s and early 19th century. Known as the "Father of English geology", Smith recognized

5180-533: The way that they are made by an organism, their chemical structure and their limited solubility in water compared to oils. They have a high carbon and hydrogen content and are considerably lacking in oxygen compared to other organic compounds and minerals; they tend to be relatively nonpolar molecules, but may include both polar and nonpolar regions as in the case of phospholipids and steroids. Crude oil, or petroleum , and its refined components, collectively termed petrochemicals , are crucial resources in

5254-775: The word are the Mycenaean Greek 𐀁𐀨𐀺 , e-ra-wo and 𐀁𐁉𐀺 , e-rai-wo , written in the Linear B syllabic script. Organic oils are produced in remarkable diversity by plants, animals, and other organisms through natural metabolic processes. Lipid is the scientific term for the fatty acids , steroids and similar chemicals often found in the oils produced by living things, while oil refers to an overall mixture of chemicals. Organic oils may also contain chemicals other than lipids, including proteins , waxes (class of compounds with oil-like properties that are solid at common temperatures) and alkaloids . Lipids can be classified by

5328-419: Was also used in lighting in ancient Greece and Rome. So people would use it to bulk out food so they would have more energy to burn through the day. Olive oil was also used to clean the body in this time as it would trap the moisture in the skin while pulling the grime to the surface. It was used as an ancient form of unsophisticated soap. It was applied on the skin then scrubbed off with a wooden stick pulling off

5402-409: Was deposited over the resulting unconformity. Provenance of the terrigenous material that constitutes the Barnett Shale was from Ouachita thrust sheets and the reactivation of older structures such as the Muenster Arch. Post-Barnett deposition continued without interruption as a sequence of extremely hard and dense limestones were laid down. These limestones have often been confused with the lower part of

5476-525: Was developed during the 19th century, based on the evidence of biologic stratigraphy and faunal succession. This timescale remained a relative scale until the development of radiometric dating , which was based on an absolute time framework, leading to the development of chronostratigraphy. One important development is the Vail curve , which attempts to define a global historical sea-level curve according to inferences from worldwide stratigraphic patterns. Stratigraphy

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