Content of PetroWiki is intended for personal use only and to supplement, not replace, engineering judgment. SPE disclaims any and all liability for your use of such content. Field instruments which sense the ability of the local surroundings, including soil, to conduct electricity by detecting resistance to induced electromagnetic radiation. Used to sense variations in soil EC within a field, but also responds to soil water content, porosity, type and amount of clay, electric power lines, and buried pipes.
The electrical system of a typical oil field consists of power generation, power distribution, electric motors, system protection, and electrical grounding. The power is either generated on site or purchased from a local utility company. To ensure continuous production from an oil field, it is of utmost importance that the associated electrical systems be designed adequately. Various organizations in the U.S. and other countries have developed many electrical codes and standards that are accepted by industry and governmental bodies throughout the world. These codes and standards provide guidelines or rules for design and installation of electrical systems.
The electrical power required to drive a motor has three components: reactive power (Pr, kVAR), active power (Pa, kW), and apparent power (Pap, kVA). The active power is the actual amount of work done by the motor and measured for billing purposes. The reactive power is the power required to magnetize the motor winding or to create magnetic flux, and is not recordable. The apparent power is the vector sum of kilowatts and kilovars and is the total amount of energy furnished by the utility company. The power triangles shown in Figure 1 illustrate the relationships between these terms.
The required power for the oil field is either generated on site by engine- or turbine-driven generator sets or purchased from a local utility company. The engines or turbines may use diesel or natural gas as a fuel. Some units are dual-fueled, using natural gas and diesel. Natural-gas-fueled prime movers are most practical for normal power generation for most applications. Diesel is used where natural gas is unavailable and for units that provide black-start and emergency power.
One of the options for gas monetization is gas to power (GTP), sometimes called gas to wire (GTW). Electric power can be an intermediate product, such as in the case of mineral refining in which electricity is used to refine bauxite into aluminum; or it can be an end product that is distributed into a large utility power grid. This page focuses on electricity as the end product. The primary issues related to GTP are the relative positions of the resource and the end market and transmission methods. The scale or volume of gas and/or power to be transported influences each of these issues.
Investigating the causal factors of electric line worker incidents is of high priority due to the decades-long record of incidents in the electric power industry. According to Bureau of Labor Statistics (BLS, 2018), 152 electrical line installer fatalities occurred in the U.S. in 2011 through 2016. For the individual years, the fatality numbers were 26, 27, 27, 25, 26 and 21, respectively. These rates often account for the ranking of electric line installers among the most dangerous professions in the U.S. Major contributors to electric line work incidents include electrocutions, machines, tools and vehicles (BLS, 2018). Closer inspection of these contributors reveals that their antecedents consist of attentional, strategic or knowledge factors (Reason, 1997). The study presented in this article investigates the role of sustained attention as a primary contributor to electric line worker incidents.
Little research exists concerning the safety of electric power line installers and, to the authors’ knowledge, no research is available regarding attentiveness as a causal factor of installer incidents. Specifically, the effect of sustained attention and vigilance (cognitive skills of immediate relevance to incident prevention for these workers) has not been examined. Past studies of cognitive-training regimens have evaluated both the effect on the trained task and transfer of training benefit to related but untrained cognitive tasks.
Tokyo Gas received its first cargo produced at Dominion’s Cove Point LNG terminal in May 2018 via the LNG Sakura. Japan is bringing its nuclear reactors back on line following the suspension of operations at all reactors after the 2011 Fukushima accident. As the reactors return to full operation, the increase in nuclear generation is likely to displace generation from fossil sources, in particular natural gas. Because Japan imports all of its natural gas in the form of LNG, increased nuclear power production is likely to reduce Japanese imports of LNG in the electric power sector by as much as 10% in 2019. Japan suspended operations at all nuclear reactors for mandatory safety inspections and upgrades, leaving the country with no nuclear generation from September 2013 to August 2015.
Chen, Yung-Wei (National Taiwan Ocean University) | Shih, Chao-Feng (National Taiwan Ocean University) | Liu, Yu-Chen (National Taiwan Ocean University) | Soon, Shih-Ping (National Taiwan Ocean University)
This paper presents an equal-norm multiple-scale Trefftz method (MSTM) associated with the group-preserving schemes (GPS) to tackle some difficulties in nonlinear sloshing behaviors. The MSTM combined with the vector regularization method is first adopted to eliminate the higher-order numerical oscillation phenomena and noisy dissipation in the boundary value problem. Then, the weighting factors of initial and boundary value problems are introduced into the linear system to prevent the elevation from vanishing without iterative computational controlled volume. More important, the explicit scheme, based on the GL (n, R), and the implicit scheme can be combined to reduce iteration number and increase computational efficiency. A comparison of the results shows that the proposed approach is better than previously reported methods.
Sloshing of liquid in tanks has received considerable attention from many researchers in related engineering fields. The problem arises because excessive sloshing of the confined liquid can strongly damage the structure or the loads induced by sloshing, which may seriously modify the dynamics of the vehicle that supports the tanks—for example, fuel sloshing in liquid propellant launch vehicles (Lu et al., 2015), oil oscillations in large storage tanks as a result of long-period strong ground motions (Hashimoto et al., 2017), and sloshing in nuclear fuel pools owing to earthquakes (Eswaran and Reddy, 2016). Besides, sloshing effects in the ballast tanks of a ship may cause it to experience large rolling moments and eventually capsize because of loss of dynamic stability (Krata, 2013; Sanapala et al., 2018). Also, if the forcing frequency coincides with the natural sloshing frequency, the high dynamic pressures, by reason of resonance, may damage the tank walls. Thus, accurate prediction of sloshing behaviors in tanks driven by external forces is very critical for successful structural design and reducing impacts on vehicle maneuvering.
Expected to begin production in 2022, Gimi will liquefy gas as part of the first phase of the project. It is designed to produce an average of approximately 2.5 mtpa of LNG using Black and Veatch’s PRICO liquefaction process. Keppel will fabricate the vessel at its shipyard in Singapore. Hilli Episeyo has maintained 100% uptime since beginning commercial operations offshore Cameroon in June 2018. The total gas resources in the field are estimated to be around 15 Tcf.