Geology Wikipedia. Europe, compiled by the Belgian geologist Andr Dumont. Colors indicate the distribution of different rock types across the continent, as they were known then. D Geologic Modeling Software' title='3 D Geologic Modeling Software' />Geology from the Ancient Greek, g, i. Earth, the rocks of which it is composed, and the processes by which they change over time. Geology can also refer to the study of the solid features of any terrestrial planet or natural satellite, such as Mars or the Moon. Geology describes the structure of the Earth beneath its surface, and the processes that have shaped that structure. Water information is fundamental to national and local economic wellbeing, protection of life and property, and effective management of the Nations water resources. The majority of research in geology is associated with the study of rock, as rock provides the primary record of the majority of the geologic history of the Earth. About Safe Software. Read our story and what Safe does. Put Voxlers 3D modeling abilities to work to better understand your geologic, GIS, well, borehole, and point cloud data. Software di Geologia e Geotecnica Su GeoExpo potrai trovare numerosi Software per lingegneria, la geologia e la geotecnica. Di seguito si riporta lelenco. Acronyms and Abbreviations. Contents taken from Global Change Acronyms and Abbreviations, 1995. ORNLCDIAC83, Carbon Dioxide Information Analysis Center, Oak Ridge. It also provides tools to determine the relative and absolute ages of rocks found in a given location, and also to describe the histories of those rocks. By combining these tools, geologists are able to chronicle the geological history of the Earth as a whole, and also to demonstrate the age of the Earth. Geology provides the primary evidence for plate tectonics, the evolutionary history of life, and the Earths past climates. Geologists use a wide variety of methods to understand the Earths structure and evolution, including field work, rock description, geophysical techniques, chemical analysis, physical experiments, and numerical modelling. In practical terms, geology is important for mineral and hydrocarbon exploration and exploitation, evaluating water resources, understanding of natural hazards, the remediation of environmental problems, and providing insights into past climate change. Geology, a major academic discipline, also plays a role in geotechnical engineering. D-Geomodellar-geological-modeling.jpg' alt='3 D Geologic Modeling Software' title='3 D Geologic Modeling Software' />Geologic materialseditThe majority of geological data comes from research on solid Earth materials. These typically fall into one of two categories rock and unconsolidated material. This schematic diagram of the rock cycle shows the relationship between magma and sedimentary, metamorphic, and igneous rock. The majority of research in geology is associated with the study of rock, as rock provides the primary record of the majority of the geologic history of the Earth. There are three major types of rock igneous, sedimentary, and metamorphic. The rock cycle illustrates the relationships among them see diagram. When a rock crystallizes from melt magma andor lava, it is an igneous rock. 2010 Becker Cpa Review Pdf Download. This rock can be weathered and eroded, then redeposited and lithified into a sedimentary rock. It can then be turned into a metamorphic rock from the heat and pressure that change its mineral content, resulting in a characteristic fabric. All three types may melt again, and when this happens, a new magma is formed, from which an igneous rock may once more crystallize. To study all three types, geologists evaluate the minerals of which they are composed. Each mineral has distinct physical properties, and there are many tests to determine each of them. The specimens can be tested for Luster Measurement of the amount of light reflected from the surface. Luster is broken into metallic and nonmetallic. Color Minerals are grouped by their color. Mostly diagnostic but impurities can change a minerals color. Streak Performed by scratching the sample on a porcelain plate. The color of the streak can help name the mineral. Hardness The resistance of a mineral to scratch. Breakage pattern A mineral can either show fracture or cleavage, the former being breakage of uneven surfaces and the latter a breakage along closely spaced parallel planes. Specific gravity the weight of a specific volume of a mineral. Effervescence Involves dripping hydrochloric acid on the mineral to test for fizzing. Magnetism Involves using a magnet to test for magnetism. Taste Minerals can have a distinctive taste, like halite which tastes like table salt. Smell Minerals can have a distinctive odor. For example, sulfur smells like rotten eggs. Unconsolidated materialeditGeologists also study unlithified materials referred to as drift, which typically come from more recent deposits. These materials are superficial deposits which lie above the bedrock. This study is often known as Quaternary geology, after the Quaternary period of geologic history. Whole Earth structureeditPlate tectonicseditIn the 1. Earths lithosphere, which includes the crust and rigid uppermost portion of the upper mantle, is separated into tectonic plates that move across the plastically deforming, solid, upper mantle, which is called the asthenosphere. This theory is supported by several types of observations, including seafloor spreading56 and the global distribution of mountain terrain and seismicity. There is an intimate coupling between the movement of the plates on the surface and the convection of the mantle that is, the heat transfer caused by bulk movement of molecules within fluids. Thus, oceanic plates and the adjoining mantle convection currents always move in the same direction because the oceanic lithosphere is actually the rigid upper thermal boundary layer of the convecting mantle. This coupling between rigid plates moving on the surface of the Earth and the convecting mantle is called plate tectonics. In this diagram, subducting slabs are in blue and continental margins and a few plate boundaries are in red. The blue blob in the cutaway section is the seismically imaged Farallon Plate, which is subducting beneath North America. The remnants of this plate on the surface of the Earth are the Juan de Fuca Plate and Explorer Plate, both in the northwestern United States and southwestern Canada, and the Cocos Plate on the west coast of Mexico. The development of plate tectonics has provided a physical basis for many observations of the solid Earth. Long linear regions of geologic features are explained as plate boundaries. For example Transform boundaries, such as the San Andreas Fault system, resulted in widespread powerful earthquakes. Plate tectonics also has provided a mechanism for Alfred Wegeners theory of continental drift,8 in which the continents move across the surface of the Earth over geologic time. They also provided a driving force for crustal deformation, and a new setting for the observations of structural geology. The power of the theory of plate tectonics lies in its ability to combine all of these observations into a single theory of how the lithosphere moves over the convecting mantle. Earth structureedit. The Earths layered structure. Earth layered structure. Typical wave paths from earthquakes like these gave early seismologists insights into the layered structure of the Earth. Advances in seismology, computer modeling, and mineralogy and crystallography at high temperatures and pressures give insights into the internal composition and structure of the Earth. Seismologists can use the arrival times of seismic waves in reverse to image the interior of the Earth. Early advances in this field showed the existence of a liquid outer core where shear waves were not able to propagate and a dense solid inner core. These advances led to the development of a layered model of the Earth, with a crust and lithosphere on top, the mantle below separated within itself by seismic discontinuities at 4. More recently, seismologists have been able to create detailed images of wave speeds inside the earth in the same way a doctor images a body in a CT scan. These images have led to a much more detailed view of the interior of the Earth, and have replaced the simplified layered model with a much more dynamic model. Mineralogists have been able to use the pressure and temperature data from the seismic and modelling studies alongside knowledge of the elemental composition of the Earth to reproduce these conditions in experimental settings and measure changes in crystal structure. These studies explain the chemical changes associated with the major seismic discontinuities in the mantle and show the crystallographic structures expected in the inner core of the Earth. PEH Estimation of Primary Reserves of Crude Oil, Natural Gas, and Condensate Methods to estimate reserves may be categorized as either static or dynamic. Static methods typically are used before production is initiated in a subject reservoir, and include analogy methods and volumetric methods. Computer simulation that is used before production initiation is considered a static method. Dynamic methods might be used after sustained production has been initiated, and include production trend analysis, material balance calculations, and computer simulation. Because dynamic methods typically consider well andor reservoir performance, they generally are considered more reliable than static methods. A specific reserves estimate might involve one or more such methods. What method or methods are used depends on several factors, including production history of the area, if any stage of development on the date of the estimate geologic complexity quality and quantity of data maturity of production for the subject reservoir and the purpose of the estimate. Each estimate should be corroborated using an alternate, preferably independent, method. Analogy Methods. Analogy methods typically are used to estimate ultimate recoveryor unit recovery factorsof oil andor gas for undrilled locations and to supplement volumetric methods of estimating reserves in the early stages of development and production. The analogy method assumes that the analogous reservoir or well is comparable to the subject reservoir or well in those aspects that control ultimate recovery of oil andor gas. The methods weakness is that this assumptions validity cannot be determined until the subject reservoir or well has been produced long enough to estimate reserves using dynamic methods. In some scenarios, analogy may be the only feasible method until there are sufficient pressure andor production data for a reliable analysis of performance. Such scenarios include areas of widely spaced development, where subsurface information might be too sparse to facilitate reliable volumetric mapping, and reservoirs where log, core, andor test data are insufficient for reliable characterization. There are two broad categories of analogy methods analytical and statistical. Regardless of the method used, however, analogous and subject reservoirs should be similar in their structural configuration lithology and depositional environment of the reservoir rock nature and degree of principal heterogeneity average net thickness and ratio of net pay to gross pay petrophysics of the rockfluid system initial pressure and temperature reservoir fluid properties and drive mechanism spatial relationship between free gas if any, oil, and aquifer at initial conditions stacked vs. Because all these reservoir aspects seldom, if ever, are similar, judicious compensating adjustments from analogous to subject reservoir usually are needed. Such adjustments require considerable local knowledge and reservoir engineering experience. Analytical analogy methods include using recovery factors e. STBOacre ft of reservoir or recovery efficiencies percent recovery from analogous reservoirs to estimate oil andor gas reserves for wells or reservoirs being studied. Basic rock andor fluid parametersporosity, water saturation, and formation volume factor FVFmay be used with, or as modifiers to, these recovery factors or recovery efficiencies. For example, the recovery factor observed in an analogous reservoir FRA might be adjusted by. ShiS and ShiA refer to subject and analogous reservoirs, respectively. Depending on circumstances, more complex relations might be appropriate, such as one or more of the factorial groups in Eqs. Recovery Efficiency section below. In many areas, estimates of rock propertiesporosity, initial water saturation, and net paymade from wireline logs are subject to considerable uncertainty. Without core data or definitive formation tests, analogy may be the only method available initially to estimate reserves. Analogies can be drawn from mature reservoirs in comparable geologic and engineering settings. Several examples are provided for mature areas in the U. S. A. Using American Petroleum Institute API data,1. REs were estimated3 for groups of oil reservoirs in various regions in the U. S. A. Table 1. 8. Comparable data on natural gas reservoirs in the U. S. A. have not been published. From Table 1. Louisiana, for example, the respective influence of lithology and drive mechanism on RE 2 for Oklahoma and Pennsylvania, for example, the significant difference in waterflood ultimate RE, which probably results from the Pennsylvania waterfloods significantly poorer rock quality 3 for southern Louisiana and the Texas Gulf Coast, for example, the reasonable agreement in waterdrive RE. The slightly higher quality sands in the Louisiana Gulf Coast probably cause small differences. Table 1. 8. 1. From a review of these admittedly limited data, it appears that variations in aggregate oil RE between regions are attributable principally to differences in reservoir rockfluid systems and reservoir drive mechanisms. SPEE has published additional, useful summary discussions of regional variations in rock quality and reservoir drive mechanism for various areas in the U. S. A. 1. 6In 1. 98. API published estimates of oil initially in place OIP and primary RE for 5. U. S. A. and estimates of primary and waterflood RE for 2. U. S. A. 1. 7 Table 1. Estimates such as these can be developed for other areas using detailed data published annually by most U. S. A. state oil and gas regulatory commissions, the Alberta Energy Resource Conservation Board ERCB which since 1. Alberta Energy and Utilities Board EUB, the Saskatchewan Dept. Energy and Mines, various regional geological societies, and other such agencies. This type of regional data might be useful in making preliminary estimates of reserves, pending development of specific data for the wellreservoir in question. Table 1. 8. 2. Information presented in Tables 1. Statistical analogy methods include using per well recoveries of oil andor gas from analogous wells in the same producing trend or in analogous geologic settings to estimate recoveries from wells being studied. Two types of statistical analogy methods are discussed here isoultimate recovery maps and analysis of observed frequency distributions of ultimate recovery. Additional comments are provided in the Recovery Efficiency section below. When analogy methods are used to estimate reserves for individual wells, the analogous and subject wells should be similar regarding well completion, including stimulation type if any production method initial absolute open flow potential for gas wells initial potential andor productivity index for oil wells well spacing and economic limit. In some producing areas, ultimate recovery of oil or gas from individual wells may be controlled by geologic trends such as depositional environment, intensity of fracturing, or degree of diagenesis. In such cases, an isoultimate recovery map can be made by posting and contouring estimated ultimate recovery from individual wells in the area of interest. Such a map can be used to estimate reserves for undrilled tracts, but one should use this technique cautiously Nongeologic factors might control ultimate recovery of oil or gas. Different completion and stimulation procedures may yield different ultimate recoveries from individual wells. For example, for wells in several areas of the U. S. A., a correlation has been observed between size of fracture treatment and ultimate recovery. Thus, before relying on isoultimate recovery maps, one should determine whether there is a statistically valid relation between ultimate recovery and the completion or stimulation method or another parameter.