The Experts below are selected from a list of 306 Experts worldwide ranked by ideXlab platform
Nikolaos Nikiforakis - One of the best experts on this subject based on the ideXlab platform.
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Multiphysics modeling of the initiating capability of Detonators. I. The underwater test
Journal of Applied Physics, 2021Co-Authors: Eleftherios Ioannou, Nikolaos NikiforakisAbstract:Detonators are explosive devices used for the initiation of secondary explosives in commercial and military applications. They are characterized by their initiating capability, which is a critical factor for their safe and effective use but challenging to assess accurately. In this two-part study, we employ numerical simulations to investigate the blast wave generated by Detonators and examine their initiating capability. The first part, presented here, follows the European underwater test of initiating capability, which evaluates Detonators in isolation (direct method) and the second part considers Detonators placed within a receiving explosive charge (indirect method). In the underwater test, the Detonator is ignited inside a water tank and the initiating capability is assessed through pressure measurements in the far field. We employ a multiphysics methodology that allows the use of distinct mathematical models for each component such as two-phase reactive materials, elastic–plastic solids, and inert fluids. The computational implementation is validated against underwater experiments and is employed for the simulation of the blast wave generated by different types of Detonators. The initial focus is on the general characteristics of the blast wave and subsequently on the differences between Detonators of different shell material and thickness. Results show that the blast wave in the near field is asymmetric and varies significantly between Detonators, but these features do not persist in the far field. The underwater test considers only the far field and is thus unable to capture the near field differences, which have a significant impact on the initiation of secondary explosives.
Edl Schamiloglu - One of the best experts on this subject based on the ideXlab platform.
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Electromagnetic Modeling of Hot-Wire Detonators
IEEE Transactions on Microwave Theory and Techniques, 2009Co-Authors: M.r. Lambrecht, K.l. Cartwright, Carl E. Baum, Edl SchamilogluAbstract:An effort is underway to determine the electromagnetic (EM) characteristics of hot-wire Detonators in order to quantify more precisely how they might respond to modern EM illumination. These analyses provide a precise tailored approach to EM safety and insights into IEEE Standard C95.7-2005. The analyses include a comprehensive investigation of physical Detonator characteristics, which is then used to model Detonators using EM theory. The theoretical analysis treats the Detonator as a cascaded transmission line incorporating several different dielectric regions, and examines both differential and common mode excitation for a generic Detonator geometry. This model is then implemented in MATLAB and is used to calculate the input impedance for the Detonator from dc to 9 GHz. This program can then be used to quickly investigate similarly constructed hot-wire Detonators by simply varying the input parameters. The model is used to predict the input impedance for a state-of-the-art blasting cap, and these predictions are then compared with experimental measurements.
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Characterization of Hot-Wire Detonators Using Analytical Modeling and Computational Tools
2008 DoD HPCMP Users Group Conference, 2008Co-Authors: M.r. Lambrecht, Carl E. Baum, Edl Schamiloglu, Keith CartwrightAbstract:An effort is underway to determine the electromagnetic (EM) characteristics of hot-wire Detonators to quantify the possible effects of EM radiation. The analyses include a comprehensive investigation of physical Detonator characteristics, which is then used to model Detonators using EM theory and numerical simulations. The theoretical analysis treats the Detonator as a cascaded transmission line incorporating several different dielectric regions, and examines both differential and common mode excitation. In addition, the Detonator is modeled and simulated using ICEPIC (Improved Concurrent electromagnetic particle in cell), a finite-difference-time-domain (FDTD) EM solver. The cascaded transmission line model is then augmented with additional circuit elements whose values are found using ICEPIC. This combination produces a refined transmission line model that is implemented in MATLAB and can be run quickly for a wide range of Detonators to determine possible deviations in radio frequency (RF) response due to manufacturing variations. A detailed RF response is not a given specification for Detonators and, therefore, it is not a characteristic that is controlled during manufacturing. The results of both the analytic and computational methods, including Detonator input impedance and resonant frequencies, are compared.
James M. Barker - One of the best experts on this subject based on the ideXlab platform.
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Unique electrical Detonator enhances safety in explosive operations : Case histories
1997Co-Authors: Jerry D. Motley, James M. BarkerAbstract:The electroexplosive devices most commonly used in today's oilfield operations include hot-wire Detonators, resistorized Detonators, exploding bridgewire devices, and exploding foil initiators. Each of these Detonators functions differently and is subject to inherent operational, safety, and/or economic drawbacks. To overcome limitations of the present devices, a new type of electrical Detonator has been designed. The new device, designated the rig-type environment Detonator, utilizes semiconductor bridge technology and deflagration-to-detonation techniques with secondary explosives and does not require primary explosives, special surface firing panels, or downhole firing units in order to function. The new detonating device is insensitive to common wellsite hazards from radio transmissions, electrostatic discharge, cathodic protection, and welding, which have caused problems with other Detonators, and thus, can significantly enhance operational safety. In addition, the new device is cost efficient and versatile as the different embodiments of the device allow it to be easily adapted for use with other common downhole explosive hardware and surface firing panels. A description of the qualification tests to which the new Detonator has been subjected will be presented and will compare its safety and operational capabilities to that of other traditionally used devices. Case histories of its usage to date and evaluations from independent testing authorities in both the U.S. and U.K. attest to its safety and reliability for oilfield explosive operations.
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Unique Electrical Detonator Enhances Safety in Explosive Operations: Case Histories
All Days, 1996Co-Authors: Jerry D. Motley, James M. BarkerAbstract:Abstract The electroexplosive devices most commonly used in today's oilfield operations include hot-wire Detonators, resistorized Detonators, exploding bridgewire devices, and exploding foil initiators. Each of these Detonators functions differently and is subject to inherent operational, safety, and/or economic drawbacks. To overcome limitations of the present devices, a new type of electrical Detonator has been designed. The new device, designated the rig-type environment Detonator, utilizes semiconductor bridge technology and deflagration-to-detonation techniques with secondary explosives and does not require primary explosives, special surface firing panels, or downhole firing units in order to function. The new detonating device is insensitive to common wellsite hazards from radio transmissions, electrostatic discharge, cathodic protection, and welding, which have caused problems with other Detonators, and thus, can significantly enhance operational safety. In addition, the new device is cost efficient and versatile as the different embodiments of the device allow it to be easily adapted for use with other common downhole explosive hardware and surface firing panels. A description of the qualification tests to which the new Detonator has been subjected will be presented and will compare its safety and operational capabilities to that of other traditionally used devices. Case histories of its usage to date and evaluations from independent testing authorities in both the U.S. and U.K. attest to its safety and reliability for oilfield explosive operations. Introduction Many of the services such as jet perforating of wellbores, tubing and casing cutting, and wellhead and platform removal that are conducted in oilfield operations today are run on electric wireline, and electroexplosive devices (EEDs) are needed to initiate the explosive trains for these services. Hot-wire Detonators, resistorized Detonators, exploding bridgewire (EBW) devices, and exploding foil initiators (EFIs) have traditionally been used for this purpose. These devices are often subjected to environments that have potential for stray electrical and electromagnetic hazards with possible sources being electric batteries (12- and 24-volt), cathodic protection systems (potentials to 50 VDC), welding units (potentials to 70 VDC), and radio frequency (RF) transmissions. The hot-wire and resistorized Detonators are extremely sensitive to these hazards, so much so that it is a required practice when using these devices to shut down cathodic protection, welding, and radar/radio transmissions before conducting explosive operations. In addition, stray voltages greater than 0.25 volts must be traced and corrected before commencing explosive operations. On the other hand, the EBW and EFI devices are so insensitive to wellsite electrical hazards that they require a special downhole, high-voltage, firing unit (and sometimes surface firing panel) to function. Because of this insensitivity, when using the EBW and EFI systems, the requirements for shutting down of cathodic protection, welding and RF transmissions can often be waived. Also, they can be used in environments where stray voltages are in the range of 30 to 40 volts. This is possible because their functioning voltage is on the order of 150 to 160 volts, which provides an ample margin of safety. The primary drawback of EBW and EFI Detonators, however, is their high cost, which can range from several hundred to several thousand dollars per shot. A secondary drawback to EBWs and EFIs is their difficulty to adapt to existing explosive hardware such as select-fire systems and bottom-fired port plug guns. A new type of electrical Detonator has been developed to overcome the hazard limitations of hot-wire and resistorized Detonators as well as the extensive cost and adaptation limitations of EBW and EEl devices. The method of operation for the new device, the rig-type environment Detonator (RED), is based on semiconductor bridge technology and deflagration-to-detonation techniques with secondary explosives. This new Detonator is insensitive to common wellsite hazards, and its safe method of operation allows certain operational procedures to be waived during performance of perforating services. P. 633
M.r. Lambrecht - One of the best experts on this subject based on the ideXlab platform.
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Electromagnetic Modeling of Hot-Wire Detonators
IEEE Transactions on Microwave Theory and Techniques, 2009Co-Authors: M.r. Lambrecht, K.l. Cartwright, Carl E. Baum, Edl SchamilogluAbstract:An effort is underway to determine the electromagnetic (EM) characteristics of hot-wire Detonators in order to quantify more precisely how they might respond to modern EM illumination. These analyses provide a precise tailored approach to EM safety and insights into IEEE Standard C95.7-2005. The analyses include a comprehensive investigation of physical Detonator characteristics, which is then used to model Detonators using EM theory. The theoretical analysis treats the Detonator as a cascaded transmission line incorporating several different dielectric regions, and examines both differential and common mode excitation for a generic Detonator geometry. This model is then implemented in MATLAB and is used to calculate the input impedance for the Detonator from dc to 9 GHz. This program can then be used to quickly investigate similarly constructed hot-wire Detonators by simply varying the input parameters. The model is used to predict the input impedance for a state-of-the-art blasting cap, and these predictions are then compared with experimental measurements.
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Characterization of Hot-Wire Detonators Using Analytical Modeling and Computational Tools
2008 DoD HPCMP Users Group Conference, 2008Co-Authors: M.r. Lambrecht, Carl E. Baum, Edl Schamiloglu, Keith CartwrightAbstract:An effort is underway to determine the electromagnetic (EM) characteristics of hot-wire Detonators to quantify the possible effects of EM radiation. The analyses include a comprehensive investigation of physical Detonator characteristics, which is then used to model Detonators using EM theory and numerical simulations. The theoretical analysis treats the Detonator as a cascaded transmission line incorporating several different dielectric regions, and examines both differential and common mode excitation. In addition, the Detonator is modeled and simulated using ICEPIC (Improved Concurrent electromagnetic particle in cell), a finite-difference-time-domain (FDTD) EM solver. The cascaded transmission line model is then augmented with additional circuit elements whose values are found using ICEPIC. This combination produces a refined transmission line model that is implemented in MATLAB and can be run quickly for a wide range of Detonators to determine possible deviations in radio frequency (RF) response due to manufacturing variations. A detailed RF response is not a given specification for Detonators and, therefore, it is not a characteristic that is controlled during manufacturing. The results of both the analytic and computational methods, including Detonator input impedance and resonant frequencies, are compared.
Eleftherios Ioannou - One of the best experts on this subject based on the ideXlab platform.
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Multiphysics modeling of the initiating capability of Detonators. I. The underwater test
Journal of Applied Physics, 2021Co-Authors: Eleftherios Ioannou, Nikolaos NikiforakisAbstract:Detonators are explosive devices used for the initiation of secondary explosives in commercial and military applications. They are characterized by their initiating capability, which is a critical factor for their safe and effective use but challenging to assess accurately. In this two-part study, we employ numerical simulations to investigate the blast wave generated by Detonators and examine their initiating capability. The first part, presented here, follows the European underwater test of initiating capability, which evaluates Detonators in isolation (direct method) and the second part considers Detonators placed within a receiving explosive charge (indirect method). In the underwater test, the Detonator is ignited inside a water tank and the initiating capability is assessed through pressure measurements in the far field. We employ a multiphysics methodology that allows the use of distinct mathematical models for each component such as two-phase reactive materials, elastic–plastic solids, and inert fluids. The computational implementation is validated against underwater experiments and is employed for the simulation of the blast wave generated by different types of Detonators. The initial focus is on the general characteristics of the blast wave and subsequently on the differences between Detonators of different shell material and thickness. Results show that the blast wave in the near field is asymmetric and varies significantly between Detonators, but these features do not persist in the far field. The underwater test considers only the far field and is thus unable to capture the near field differences, which have a significant impact on the initiation of secondary explosives.