Browsing by Subject "Oil and Gas"

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Arc Initiation for the Electromagnetic Powder Deposition Gun
(1997-09) Sledge, R.L.; Bacon, J.L.; Davis, D.G.; Polizzi, R.J.; Uglum, J.R.; Zowarka, R.C.
The instrumentation, interpretation of data, and subsequent decisions regarding the direction of system development are discussed. Important system parameters, their impact on system performance, and techniques to measure them are presented. The electromagnetic powder deposition system is based on railgun technology developed by the Department of Defense. The system drives an ionized plasma sheet down the length of a railgun, reaching a final plasma velocity of 4 km/sec. The high velocity plasma, in turn, snowplows a shock compressed gas column in front of it. This gas column sweeps through a powder cloud and accelerates it by viscous drag to a final velocity of 2 km/sec. Important system parameters include particle velocity, gas velocity, gas column pressure, and plasma propagation and velocity. Diagnostic tools include pressure transducers, a high speed digital framing camera, fiber optics and magnetic probes.
Effect of Temperature on Wear Rate of Homopolar Pulse Consolidated Electrical Brush
(Elsevier, 1993-07) Liu, H-P.; Carnes, Jr, R.W.; Gully, J.H.
Binderless copper-graphite composite electrical brushes are being developed using a high-energy, high-rate pulse sintering technique by the Center for Electromechanics at The University of Texas at Austin (CEM-UT). Experiments were done to investigate temperature's effect on the homopolar pulse consolidated (HPC) brush wear rate for an apparent brush current density of 180 A cm−2, a brush downforce of 44.5 N, and rotor surface sliding speeds of 10 m s−1 and 40 m s−1. At a sliding speed of 10 m s−1, it was found that brush wear rate dropped steeply as the brush bulk temperature increased from 80 °C to 103 °C. Other than this unusual wear finding in this particular sliding speed and temperature range, test results indicated that brush wear rate generally increased with increasing brush bulk temperature. At a sliding speed of 40 m s−1, it was found that brush wear rate suddenly increased by several times as the brush bulk temperature approached 149 °C. In the case of 10 m s−1 sliding speed, no stepwise rise in brush wear rate was observed even as the brush bulk temperature reached 156 °C.
Electromagnetic Powder Deposition Experiments
(IEEE, 1999-01) Zowarka, R.C.; Bacon, J.L.; Davis, D.G.; Sledge, R.L.; Uglum, J.R.; Driga, M.D.
The US Department of Defense (DoD) and commercial entities are dependent on chemical plating and coating processes to replace worn or eroded material on damaged parts. Logistics Centers have been forced to consider replacement materials for repair operations due to the tightening of government regulations on the use of toxic and hazardous materials. This paper describes a new process capable of fulfilling many of these requirements. Existing state-of-the-art thermal spray processes (HVOF, D-gun, plasma spray) are limited to powder velocities of about 1 km/s because they rely on the thermodynamic expansion of gases. A new thermal spray process using electromagnetic forces can accelerate powder particles to a final velocity in excess of 2 km/s. At this velocity, powder particles have sufficient kinetic energy to melt their own mass and an equivalent substrate mass on impact. The energetics of the process allow fusion bonding of greater strength than that created by low velocity processes as well as improved coating density. This paper describes the laboratory system designed and constructed to conduct proof of principle experiments. Results of the experiments are presented along with high speed photographs of powder particles confirming system modeling and performance. The paper concludes with a discussion of the future direction of the program
Homopolar Pulsed Welding of API Line Pipe
(1992-03) Haase, P.W.; Eliezer, Z.; Carnes, R.W.; Harville, M.W.; Gully, J.H.; Trevisan, R.E.
Homopolar pulse welding is a welding process that is being developed to rapidly join API line pipe. This process has particular potential for application in offshore pipeline construction utilizing the J lay method. The weld joint produced has high strength and a narrow heat affected zone. There is a thin brittle zone at the weld interface, resulting in low impact toughness. The weld line is characterized by a very thin >light band>, believed to be a ferrite rich zone produced by a combination of localized melting and mechanical upset. Current developmental research is progressing to eliminate this brittle zone and improve weld geometry
A New Electromagnetic Powder Deposition System
(1997-09) Bacon, J.L.; Davis, D.G.; Pollizzi, R.J.; Sledge, R.L.; Uglum, J.R.; Zowarka, R.C.
Existing state of the art thermal spray processes (HVOF, D-Gun, Plasma Spraying) are limited to powder velocities of about 1 km/sec because they rely on the thermodynamic expansion of gases. A new thermal spray process using electromagnetic forces can accelerate powder particles to a final velocity of up to 2 km/sec. At this velocity powder particles have sufficient kinetic energy to melt their own mass and an equivalent substrate mass on impact. The process is based on railgun technology developed by the Department of Defense. A railgun is filled with argon gas and a high energy electrical pulse, provided by a capacitor bank, drives the gas down the railgun to a final velocity of up to 4 km/sec. This gas passes over a powder cloud and accelerates the powder through drag forces. The electrical and powder discharge frequency can be adjusted so that the deposition rate and thermal input to the substrate can be controlled.
Public Data Analysis of Parent-Child Well Relationships Across US Unconventional Basins
(2020-12) Cozby, Joe Wilson
Parent-child wells are horizontal wells drilled in close proximity to each other in unconventional basins. Simulation work in the technical literature demonstrates how the depletion effects and fracture communication between parent and child wells can lead to child well underperformance. High-level, basin-wide data analysis of unconventional basins confirms this effect. However, as completion designs evolve and more state-of-the-art horizontal wells are completed in these basins, it is necessary to revisit this analysis and make adjustments and additions to the previous body of work. Specifically, initial production differences between parent and child wells need to be correlated to cumulative production differences, and more analysis regarding the effect of timing and spacing were in order. In this study, parent-child well pairs for wells completed within the last seven years in nine different unconventional basins are identified with Python code and Enverus public data obtained in November 2020. Those basins include the Bakken, Delaware, Eagle Ford, Haynesville, Marcellus/Utica, Midland, Niobrara, Powder River, and Scoop/Stack Basins. In Python, calculations are performed to create the necessary comparative metrics for analysis. Four cumulative production proxies are created and First 12 Months BOE (barrel of oil equivalent) is chosen as the appropriate metric for analysis. Basin-to-basin comparisons are conducted, and the effects of well spacing and infill timing are investigated. The study finds that as stated in the technical literature, child well performance increases with spacing and decreases with infill timing but asserts that parent produced BOE at child completion is a better indicator of child performance. Additionally, the study finds that child well productivity decreases with parent proppant loading and increases with child proppant and fluid loading. Overall, these assessments can help operators manage child well underperformance and can help them understand the effects of differing completion metrics on child well performance in different US unconventional basins.
Scaling Analysis of the Electromagnetic Powder Deposition Gun
(1997-09) Uglum, J.R.; Bacon, J. L.; Davis, D.G.; Polizzi, R.J.; Sledge, R.L.; Zowarka, R.C.
The electromagnetic powder deposition (EPD) system employs high velocity gas flow to accelerate powder material to conditions required for high strength plating. The gas flow, however, is not continuous; rather it consists of bursts generated by an electromagnetic railgun and pulsed power system. Each gas burst is created by a high pressure plasma arc which fills a transverse section of the gun. This current carrying arc is driven by the railgun Lorentz force (magnetic pressure) and acts much like a piston, which via a snowplow process accelerates and compresses an ambient gas column to the flow speed required to accelerate powder particles. Analysis of the total system was carried out to provide scaling relations which give guidance in design of the system. Plating considerations define a desired powder velocity; this combined with the choice of working gas and ambient pressure determines the velocity and duration of each gas burst. Selection of gun geometry completes the definition of the pulsed power system requirements. An outline of the analysis is presented along with the physical models used.