Shale occurring

Mining wastes and overburden. Estonian kukersite oil shales occur in limestone strata (Schmidt 1858, 1881), yielding a carbonate-rich spoil with significant potential for acid neutralisation. Other oil shales, for example, the siliceous Estonian Dictyo-nema shales, which contain only traces of carbonate compared with the kukersites, are associated with sulphides, such as pyrite, and may thus generate acidic leachate due to pyrite oxidation (Puura Pihlak 1998 Puura et al. 1999). 

Lens-Type Traps. These form in limestone and sand. In this type of trap the reservoir is sealed in its upper regions by abrupt changes in the amount of connected pore space within a formation. A trap formed in sand is shown in Fig, 7(a). An example is the Burbank Field in Osage County, Oklahoma. This type of trap may occur in sandstones where irregular deposition of sand and shale occurred at the time the formation was laid down. In these cases, oil is confined within the porous parts of the rock hy the nonporous parts of rock surrounding it. A lens-type trap formed in limestone is shown in Fig. 7(b). In limestone formations there are frequent areas of high porosity with a tendency to form traps. Examples of limestone reservoirs of this type are found in the limestone fields of West Texas. 

Another useful tool for determining fault seal characteristics is the shale smear map. Although the fault seal probability calculation, derived from an empirical database which contains faults which were affected by shale smear, already incorporates a shale smear factor (see also Lindsay et al., 1993), the purpose of producing shale smear maps is to define the shale smear envelope for individual shale beds across fault surfaces. They can also be used as an independent check on the fault seal probability calculations. Only one shale smear map was produced in the study, for the Revfallet Fault Complex, where the greatest thickness of syn- to post-rift shale occurs. 

The eastern shales occur over a wide expanse from New York to Oklahoma and from Iowa to Alabama (JO, yet as rocks that must be... 

The lower unit of the Ohio Shale which is present in the outcrop area of eastern Kentucky is the Huron Member. Primarily, the Huron consists of black to brownish-black to gray-black, laminated, siliceous, OM-rich shales. Calcareous laminae, cone-incone limestone, dolomitic gray shales, dolomite beds and biotur-bated greenish-gray shales occur as interbeds and laminae in the lower parts of the member. Pyrite occurs as framboids, nodules, and irregular forms. 

Most of the sulfur in oil shale occurs in pyrite and a smaller amount is contained in the kerogen. The major source of H2S during oil shale pyrolysis appears to be the reaction of pyrite with organic matter. In an autogenous atmosphere, most of the H2S evolves between 400 and 500°C. Addition of finely ground pyrite increases the amount of H2S evolved but does not change the evolution profile. In an argon atmosphere, however, added pyrite causes a substantial increase in H2S evolution... 

Invert emulsion drilling fluids are commonly selected for their temperature stability and their ability to prevent the wellbore stability problems associated with the hydration of clays in shale formations. The thermodynamic activity aw of the water in the aqueous (dispersed) phase is controlled by the addition of a salt (usually calcium chloride) to ensure that it is equal to or less than the activity of the water in the drilled shale formations. The emulsified layer around the water droplets is claimed to act as a semipermeable membrane that allows the transport of water into and out of the shale but not the transport of ions (61). When the activities (or, more strictly, the chemical potentials) of the water in the shale and invert emulsion are equal, then no net transport of water into or out of the shale occurs (i.e., the drilling fluid does not hydrate or dehydrate the shale). This equality of water activity has lead to the development of so-called balanced activity oil-based drilling fluids. 

Oil shales occur worldwide, span geologic time from Cambrian to present, and were deposited principally in large freshwater lakes (lacustrine environment), shallow seas and continental shelves (marine environment), and in small lakes, bogs and lagoons associated with coal-producing swamps (paludal environment). Oil shale deposits occur in at least SO countries and the estimated world supply of potential oil from shale is S X 10 barrels. Shale oil industries in Scotland, Australia, France, Russia and China have been active since about 1860. In Australia, France and Scotland oil shales have been the source of products similar to that obtained from petroleum. However, the discovery of petroleum in the United States in 1859, and elsewhere soon after, sound the death knell for the economic production of shale oil and the situation remains much the same today. Limited, but continued use of oil shale as an energy resource has been made since about 1909 in China and 1916 in Rus. In Brazil, a pilot plant has been in operation since 1982 and has produced over a million barrels of ale oil. Oil shale is used for some power generation in Israel, and in Australia a new oil shale demonstration plant has been scheduled for construction in the near future. 

The Barnett Shale formation is located in the Fort Worth Basin of north-central Texas. It is a Mississippian-age black shale occurring at a depth of 6500 to 8500 feet (Table 5.2) and is bounded by limestone formations above (Marble Falls Limestone) and below (Chappel Limestone) (Figure 5.2). With 15,306 wells drilled or pending, the Barnett Shale was the most prominent shale gas play in the United States, but the Flaynesville Shale gas play has surpassed Barnett in shale gas production (Railroad Commission of Texas, 2009 ... 

The New Albany Shale is an organic-rich geologic formations located in the Illinois Basin in portions of southern Illinois, southwestern Indiana, and northwestern Kentucky (IGS, 1986). Similar to the Antrim Shale, the New Albany Shale occurs at depths between 500 and 2000 feet (Table 5.8) and is a shallower, water-filled shale with a more CBNG-like character than the other gas shales discussed in this text. The New Albany formation is a Devonian- to Mississippian-age Shale bounded by limestone above (Rockford Limestone) and below (North Vernon Limestone) (Figure 5.8). The New Albany Shale is one of the largest shale gas plays, encompassing an area of approximately 43,500 square miles with approximately 80-acre spacing between wells. Similar to the Antrim Shale, the New Albany play has a... 

Resources for Potash Fertilizers. Potassium is the seventh most abundant element in the earth s cmst. The raw materials from which postash fertilizer is derived are principally bedded marine evaporite deposits, but other sources include surface and subsurface brines. Both underground and solution mining are used to recover evaporite deposits, and fractional crystallization (qv) is used for the brines. The potassium salts of marine evaporite deposits occur in beds in intervals of haUte [14762-51-7] NaCl, which also contains bedded anhydrite [7778-18-9], CaSO, and clay or shale. The K O content of such deposits varies widely (see Potassium compounds). 

Fluorspar occurs in two distinct types of formation in the fluorspar district of southern Illinois and Kentucky in vertical fissure veins and in horizontal bedded replacement deposits. A 61-m bed of sandstone and shale serves as a cap rock for ascending fluorine-containing solutions and gases. Mineralizing solutions come up the faults and form vein ore bodies where the larger faults are plugged by shale. Bedded deposits occur under the thick sandstone and shale roofs. Other elements of value associated with fluorspar ore bodies are zinc, lead, cadmium, silver, germanium, iron, and thorium. Ore has been mined as deep as 300 m in this district. 

Hydrocarbon resources can be classified as organic materials which are either mobile such as cmde oil or natural gas, or immobile materials including coal, lignite, oil shales, and tar sands. Most hydrocarbon resources occur as immobile organic materials which have a low hydrogen-to-carbon ratio. However, most hydrocarbon products in demand have a H C higher than 1.0. 

The lanthanides, distributed widely in low concentrations throughout the earth s cmst (2), are found as mixtures in many massive rock formations, eg, basalts, granites, gneisses, shales, and siUcate rocks, where they are present in quantities of 10—300 ppm. Lanthanides also occur in some 160 discrete minerals, most of them rare, but in which the rare-earth (RE) content, expressed as oxide, can be as high as 60% rare-earth oxide (REO). Lanthanides do not occur in nature in the elemental state and do not occur in minerals as individual elements, but as mixtures. 

Mercury ore deposits occur in faulted and fractured rocks, such as limestone, calcareous shales, sandstones, serpentine, chert, andesite, basalt, and rhyolite. Deposits are mostiy epithermal in character, ie, minerals were deposited by rising warm solutions at comparatively shallow depths from 1—1000 m (6). 

Estimates of oil shale deposits by continent are given in Table 1 (2). Characteristics of many of the world s best known oil shales are summarized in Table 2 (3,4). Oil shale deposits in the United States occur over a wide area (Table 3). The most extensive deposits, covering ca 647,000 km (250,000 mi ), are the Devonian-Mississippian shales of the eastern United States (5). The richest U.S. oil shales are in the Green River formation of Colorado, Utah, and Wyoming. Typical mineral and organic analyses for Green River oil shale are given in Table 4. 

Temperature and Product Yields. Most oil shale retorting processes are carried out at ca 480°C to maximize liquid product yield. The effect of increasing retort temperature on product type from 480 to 870°C has been studied using an entrained bed retort (17). The oil yield decreased and the retort gas increased with increased retorting temperature the oil became more aromatic as temperature increased, and maximum yields of olefinic gases occurred at about 760°C. Effects of retorting temperatures on a distillate fraction (to 300°C) are given in Table 6. 

Carbonate Decomposition. The carbonate content of Green River oil shale is high (see Table 4). In addition, the northern portion of the Piceance Creek basin contains significant quantities of the carbonate minerals nahcoUte and dawsonite. The decomposition of these minerals is endothermic and occurs at ca 600—750°C for dolomite, 600—900°C for calcite, 350—400°C for dawsonite, and 100—120°C for nahcohte. Kinetics of these reactions have been studied (19). Carbon dioxide, a product of decomposition, dilutes the off-gases produced from retorting processes at the above decomposition temperatures. 

Water Quality. AH commercial oil shale operations require substantial quantities of water. AH product water is treated for use and operations are permitted as zero-discharge facHities. In the Unocal operation, no accidental releases of surface water have occurred during the last four years of sustained operations from 1986 to 1990. The Unocal Parachute Creek Project compliance monitoring program of ground water, surface water, and process water streams have indicated no adverse water quaHty impacts and no violations of the Colorado Department of Health standards (62). 

United States. In 1980, Unocal began constmcting the Parachute Creek Project, designed to produce 1600 m (10,000 bbl) of upgraded shale oil per day. The project included a conventional underground room-and-pikar mine, the Unishale B (see Table 7) retort, and a special Unocal upgrading facihty. Plant startup occurred in 1986, and daily shale oil production reached 1100 m /d (7000 bbl/d). By 1991, total production exceeded 0.6 x 10 m (four million barrels). However, the Parachute Creek Project was shut down in mid-1991 for economic reasons. 

Addition of a salt can transform the shale by cation exchange to a less sensitive form of clay, or reduce the osmotic swelling effect by reducing the water activity in the mud below that which occurs in the shale. These effects depend on the salt concentration and the nature of the cation. Salts containing sodium, potassium, calcium, magnesium, and ammonium ions ate used to varying degrees. 

The term tar sands is a misnomer tar is a product of coal processing. Oil sands is also a misnomer but equivalent to usage of "oil shale." Bituminous sands is more correct bitumen is a naturally occurring asphalt. Asphalt is a product of a refinery operation, usually made from a residuum. Residuum is the nonvolatile portion of petroleum and often further defined as atmospheric (bp > 350° C) or vacuum (bp > 565° C). For convenience, the terms "asphalt" and "bitumen" will be used interchangeably in this article. 

Barium [7440-39-3] Ba, is a member of Group 2 (IIA) of the periodic table where it Hes between strontium and radium. Along with calcium and strontium, barium is classed as an alkaline earth metal, and is the densest of the three. Barium metal does not occur free in nature however, its compounds occur in small but widely distributed amounts in the earth s cmst, especially in igneous rocks, sandstone, and shale. The principal barium minerals are barytes [13462-86-7] (barium sulfate) and witherite [14941-39-0] (barium carbonate) which is also known as heavy spar. The latter mineral can be readily decomposed via calcination to form barium oxide [1304-28-5] BaO, which is the ore used commercially for the preparation of barium metal. 

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