There is considerable interest in predicting the permeability arising from the detonation of explosives emplaced in low permeability geological formations. These predictions would be useful for applications such as hydrogeology (Sarbhukan, 1990), massive explosive stimulation of tight gas reservoirs (Li and Xue, 2000), shale gas formations (Guo et al, 2014), coal gasification (Zhu et al, 2013), stimulation of geothermal reservoirs (Austin et al, 1973), and fracturing oil shale with explosives (Miller and Johansen, 1976). It is well known that energy released during blasting causes damage in the surrounding rocks in the form of micro to macro cracks, which increases the permeability of rocks. It is therefore of prime importance in reservoir …show more content…
Sometimes certain physical characteristics related to explosion cannot be scaled to practical experimental set up.
On the other hand, computational methods have been broadly applied to study blast-induced fractures in rocks. The finite element method (FEM) (Zhu et al. 2008), discrete element method (DEM) (Potyondy et al. 1996), combined finite-discrete element method (FEM-DEM) (Trivino and Mohanty, 2015), combined discrete element method-smoothed particle hydrodynamics (DEM-SPH) (Fakhimi and Lanari, 2015) and combined finite element method-smoothed particle hydrodynamics (FEM-SPH) method (Gharehdash et al, 2016) have been successfully adopted to investigate the blasting-induced fracture patterns in rocks. The approaches hold promise for this class of rock fracture problems. Numerical predictions of these methods could provide useful knowledge for blast induced fracture problems. However, dealing with the large deformation and post-failure is generally a difficult task for FEM since this method is a grid-based technique. It thus suffers from grid distortions, which lead to inaccuracies in the solution or even to failure of the computation. DEM simulation does not have that limitation; however, specification of DEM parameters is somewhat ambiguous, and reliable guidelines have not yet been clearly established. Combined FEM-DEM, DEM-SPH and FEM-SPH
Paragraph 1: Fracking, also known as hydraulic fracturing, is a method designed to extract oil and gas from shale rock. According to Susan L. Brantley and Anna Meyendorff from the article, The Facts on Fracking, “The word fracking comes from the fracturing that occurs when the high-pressure water is injected into the rock. The process of fracking is accomplished by drilling into the earth where a mixture of high-pressure water is drilled into the rock causing the gas to be released.” The high-pressure water can have a mixture of materials such as water, sand, and different chemicals. The pressure of the water being injected is so high that it allows gas to burst out of the head of the well. The process can be achieved through two different ways, one being more common than another. One of the processes can be done vertically but the more common method is done horizontally. According to the New York Times, when the drilling is carried by horizontally, “New pathways can be used in the rock layer. Due to new pathways being created, more gas can be released,” (Marshall, 2015). Drillers can create mini-explosions in the wells to boost flow. How do mini-explosions not increase the probabilities of earthquakes? The horizontal drilling can allow millions of gallons of high-pressure water into the fractures of shale. Chemicals can be added to the high-pressure water for the purpose of dissolving minerals as well as inserting sand to open fractures made by the drillers and kill the
The mole is a convenient unit for analyzing chemical reactions. Avogadro’s number is equal to the mole. The mass of a mole of any compound or element is the mass in grams that corresponds to the molecular formula, also known as the atomic mass. In this experiment, you will observe the reaction of iron nails with a solution of copper (II) chloride and determine the number of moles involved in the reaction. You will determine the number of moles of copper produced in the reaction of iron and copper (II) chloride, determine the number of moles of iron used up in the reaction of iron and copper (II) chloride, determine the ratio of moles of iron to moles of copper, and determine the number of atoms and formula units involved in
October 17, 18, and 19, samples were collected from multiple sites along the BSR. The class was split into groups, and samples were collected from seven separate locations along the river and WWTP. There was also a sample collected by the S which is located between sites four and five. For each of these sites, there were ten groups from other labs that also collected a sample from the BSR. At site two of the river, the location included multiple sources of possible contamination. A drainage site was located 200 yards upstream, along with a small PVC drainage pipe next to the collection site. Not only was there drainage running into the river, the site was under a bridge, and contained other trash scattered throughout the area. The
2. When 2.00 g of NaOH were dissolved in 49.0 g water in a calorimeter at 24.0 ˚C, the temperature of the
In the method of continuous variations the total number of moles of reactants is kept constant for the series of measurements. Each measurement is made with a different mole ratio of reactants. A mole ratio is ratio between the amounts in moles of any two compounds involved in a chemical reaction. Mole ratios are used as conversion factors between products and reactants in many chemistry problems.
With the age of constant industrial and technological growth has come the necessity for not only cost effective and efficient methods for industry, but also the need for obtaining fuel for the machines that make the modern world possible. Oil has become as precious a commodity as gold, if not more so; its attainments constantly driving the world's largest businesses and governments across the world into action. Naturally, a "quick-fix" solution to this problem is constantly sought after by oil companies wishing to provide oil on a massive scale. One of these drilling methods is known as induced hydraulic fracturing (also known as fracking).
In this paper, the author want to know whether human genetic patents affect subsequent scientific research and product development. They use the administrative data on successful and unsuccessful patent applications filed with the USPTO and then link the exact gene sequences required for each application with subsequent scientific research and business investment data. By using these data, they found patented genes have more valuable prior to being patented than non-patented genes. They used two quasi-experimental approaches to text their hypothesis. In the end, they found both of the approaches suggest that on average gene patents have had no effect on follow-on innovation. “This evidence of selection motivates two
Methods: Due to experimental error in previous labs, we did not obtain the DNA of our original taxa. We then chose to use DNA sequences supplied by the TA from the 2016 and 2017 school year. We picked six fungal taxa obtained from differing parts of English Yew Trees, including its fruit, bark, and leaves. Using the DNA sequences given, we copied the sequence into the BLAST system found on blast.ncbi.gov, making sure to add “fungi” into the organism box and to search for somewhat similar sequences. Once the program obtained the results, we scrolled down to the first result that gave a genus and species name, with an “ITS” in the description. Using the information given in the results, we filled in the information on Table 2, including seq
Abundant amounts of resources are left to be untapped from unconventional reservoirs. (Arthur 2008) observes that about 500TCF of natural gas are contained in unconventional reservoirs. Unconventional gas reservoirs account for approximately one-third of the US natural gas production (Rafiqul, 2014). Over the years, reservoir engineers have relied on numerical simulators as a tool for modeling and predicting hydrocarbon recoveries (recovery factor) from reservoirs, which translates into the economic viablility (or not) of a petroleum asset. The accurate modeling of reservoir fluid-flow using simulators depend largely on the description of actual rock/fluid interactions that occur within the reservoir. Unlike for the case of conventional reservoir systems, the flow physics for unconventional reservoirs (Tight gas, Coal-bed methane, Shale reservoirs) are complicated by their unique features which include: extremely low permeability, complex fracture networks, non-darcy flow, Klinkenberg effects, adsorption/desorption effects and rock deformation due to variations in effective stress in the reservoirs. Accouting for all of these features into numerical
The second spectrum had five distinct signals with no signs of symmetry and therefore must be coming from the ortho isomer. For this ortho isomer the calculated and observed peak values were quite different. This could have been due to many factors. These factors include the temperature, concentration, and PH of the sample and also the type of spectrometer used.8 One major difference can be caused by the solvent used for the sample. The observed spectrum was performed using CDCl3 but it was very likely the calculated spectrum was performed using a different solvent such as DMSO. Depending on the structure, bonding behaves differently to each solvent. Another reason that the calculated values may vary from observed values is that the
Hydraulic Fracturing is a controversial method by which we are able to obtain natural gas from subterranean natural reservoirs within the earth. This process requires a shaft to be drilled vertically below the ground, and once a target depth has been reached below fresh water aquifers, horizontal drilling can occur. A long this horizontal shaft, the wellbore, a high pressurized mixture of water, chemicals, and sand is injected in order to create fractures in the oil and gas reservoirs within the rock. When the pump pressure is relieved, sand particles are left behind which keep the fractures open, providing an outlet for the natural gas to be collected. This process can produce oil or natural gas for twenty to forty years or more
In chlorambucil treated rats for 5 days (Group III), congested dilated central veins and portal tract were observed. Vacuolated hepatocytes were also detected. Most hepatocytes were noticed with dense pyknotic nuclei . (Figs. 3,4 ). In chlorambucil treated rats for 10 days (Group IV), hepatocytes with cytoplasmic vacuolations and congested central veins were frequently noticed. Hepatocytes with abnormal pyknotic nuclei were also detected. (Figs. 5,6 ) While in chlorambucil treated rats for 15 days (Group V), extensive vacuolated hepatocytes with pyknotic nuclei were seen in most hepatic lobules. Dilated congested central veins, hepatic sinusoids and portal tracts were also detected. Areas of mononuclear cellular infiltration were also
As we know, hydraulic fracturing has been used worldwide in damaged formations and formations with low conductivity but performing acid fracturing has been limited to so many operational and reservoir restriction. The main difference between acid fracturing and proppant fracturing is the way fracture conductivity is created. In proppant fracturing, a propping agent is used to prop open the fracture after the treatment is completed. In acid fracturing, acid is used to etch channels in the rock that comprise the walls of the fracture. Thus, the rock has to be partially soluble in acid so that channels can be etched in the
Faults transmissibilites have high impact on flow patterns and pressure profile in the reservoir. (Edris et al 2008) updated fault transmissibility by using automated history matching method and matching 4D seismic predictions from the simulations to observed data. To examine the successful of the work, they feed the model with new data as observed data and compared the result with history match. The results gave good match between the model and observed data. In addition, they investigated that it’s better to use the data early when build the model rather than to added it later. (Ding, et al 2005) used simulation to characterize the actual flow through the fractures and the connections between matrix and fractures in the area surrounding the well. Based on the geological DFN model a near-well fracture upscaling built to improve the
Hydraulic fracturing, which is used extensively in natural gas production, is a form of induced seismicity as the process over-pressurizes the rock until it fractures (Majer et al., 2007). There has been no occurrence of large earthquakes associated with geothermal production, though induced seismicity has been documented. These events have “few (or no) adverse physical effects on operations or on surrounding communities”; though public concern regarding the seismicity associated with EGS operations is present (Majer et al., 2007). These events do not compare to the cases where hydrocarbon production and waste disposal have induced seismic events large enough to cause significant damage. Therefore, EGS-induced seismicity should not pose a threat to geothermal energy development if quality site selection is carried out and operators understand the underlying causes. Developers must ensure community issues are handled adequately, education regarding these events is provided and, effective monitoring is undertaken. If monitored, induced seismicity can be beneficial to shed light on geothermal reservoir processes (Majer et al., 2007).