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According to several seminal investigation reports on the BP Deepwater Horizon (DWH) accident, misinterpretation of a critical test, called negative pressure test (NPT), was a major contributing cause of that disaster. NPT, according to many credible references, is the primary step to ascertain well integrity during any offshore drilling. This paper introduces a three-layer, conceptual risk analysis framework to assess the critical role of human and organizational factors in conducting and interpreting a negative pressure test. This framework has been developed by generalizing the risk assessment model that was proposed by the authors for the analysis of the conducted NPT by the DWH crew. In addition, the application of the introduced framework in this study is not limited to NPT misinterpretation. In fact, it can be generalized and be potentially useful for the risk analysis of future oil and gas drilling as well as other high-risk operations. Analysis of the developed framework in this paper confirms the results of previous studies by indicating that organizational factors are root causes of accumulated errors and questionable decisions made by personnel or management. Further analysis of this framework identifies procedural issues, economic pressure, and personnel management issues as the organizational factors with the highest influence on misinterpreting a negative pressure test. It is noteworthy that the captured organizational factors in the introduced conceptual framework are not only specific to the scope of the NPT. The three aforementioned organizational factors have been identified as common contributing causes of other offshore drilling accidents as well. 相似文献
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Deep eutectic solvents are becoming more popular nowadays since they are green, safe and often save raw materials and energy compared to organic solvent. Due to the importance of environmentally compatible solvent in multicomponent reactions, herein we report an efficient and sustainable catalyst-free synthesis of imidazo [1,2-a] pyridines via Groebke multicomponent reaction in choline chloride-based deep eutectic solvent. One-pot, three-component reaction of 2-amino pyridine, aromatic aldehydes and cyclohexyl isocyanide in six different choline chloride-based deep eutectic solvents in the absence of catalyst were examined. Urea–choline chloride was selected as an efficient solvent for this isocyanide-based multicomponent reaction and afforded the imidazo [1,2-a] pyridines in good yields of 57–87 % and reaction times of 2–6 h. The method has several advantages such as environmentally benign and biodegradable solvent, easy purification processes by a simple filtration and methodological simplicity. 相似文献
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All oil and gas pipeline systems are run by human operators (called controllers) who use computer-based workstations in control rooms to "control" pipelines. Several human factor elements could contribute to the lack of controller success in preventing or mitigating pipeline accidents/incidents. These elements exist in both the work environment and also in the computer system design/operation (such as data presentation and alarm configuration). Some work environment examples include shift hours, shift length, circadian rhythms, shift change-over processes, fatigue countermeasures, ergonomics factors, workplace distractions, and physical interaction with control system computers. The major objective of this paper is to demonstrate the critical effects of human and organizational factors and also to highlight the role of their interactions with automation (and automated devices) in the safe operation of complex, large-scale pipeline systems. A case study to demonstrate the critical role of human organizational factors in the control room of an oil and gas pipeline system is also presented. 相似文献
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The use of water as a solvent has sometimes benefits such as improving reactivities and selectivities, simplifying work-up procedures, and environmentally benign. Many carboxylic dithiocarbamic anhydride products are valuable building blocks in heterocycles and natural products. Here we present a simple one-pot synthesis of carboxylic dithiocarbamic anhydride by condensation of amines, carbon disulfide, acyl halide, or acetic anhydride in water. We obtained a variety of biologically important acyl dithiocarbamate derivatives in 82–93% yields in 10–30 min. This procedure can be used for the synthesis of thioureas from dithiocarbamates. Here, the sequential, one-pot three-component reaction of amines, carbon disulfide, and isothiocyanates provides unsymmetrical substituted thioureas in 81–91% yields. 相似文献
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Dithiocarbamate and their derivatives are of importance in medicinal chemistry due to their biological activities, in agriculture as fungicides and in organic synthesis as versatile synthetic intermediates. Green solvents such as deep eutectic solvents and polyethylene glycol are new emerging alternatives to conventional harmful organic solvents. Here, we report the synthesis of amino acid–based dithiocarbamates by one-pot three-component reaction of the electrophilic reagent, carbon disulfide and α-amino acids in deep eutectic solvent and polyethylene glycol as a catalyst and reaction media. In situ preparation of dithiocarbamates by the reaction of different amino acids and carbon disulfide, followed by addition reaction with epoxides, alkyl halides and α, β-unsaturated enones at room temperature, gave the corresponding products in 62–92 % yield with a short reaction time without any tedious workup procedures. The deep eutectic solvents and polyethylene glycol were recycled without activity or yield decrease. Therefore, the synthesis of amino acid–based dithiocarbamates in green solvents is a promising alternative to previously used procedures. 相似文献
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