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Overpressure

About: Overpressure is a research topic. Over the lifetime, 3236 publications have been published within this topic receiving 34648 citations.


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01 Jan 2008
TL;DR: In this article, a new formula has been summed up, and LS-DYNA has been used to simulate the spreading of shock wave in the air generated by TNT explosion on different conditions.
Abstract: Differences between several scholars′ forecasts of peak overpressure have been compared by the con-trastive analysis of research on TNT explosion shock wave spreading in the air.A new formula has been summed up,and LS-DYNA has been used to simulate the spreading of shock wave in the air generated by TNT explosion on different conditions.The numerical values are less than empirical formula′s.The results of the explosion with heavier load are more approximate than the forecasting results of empirical formula.So it′s necessary to do more research on explosion shock wave parameters.

12 citations

Journal Article
WU Zhenzhen1
TL;DR: In this paper, the authors constructed an oil generated overpressure model with consideration of the leakage of oil and water during the oil generation of the source rocks with type I kerogens, the effect of hydrogen index on oil generation, the compaction of water and kerogens due to the overpressure, and the change of oil density during compaction and oil expulsion.
Abstract: Oil generated overpressure model was constructed with consideration of the leakage of oil and water during the oil generation of the source rocks with type I kerogens,the effect of hydrogen index on oil generation,the compaction of water and kerogens due to the oil generated overpressure,the change of oil density during the compaction and oil expulsionThe physical simulation of overpressure caused by oil generation proves the overpressure mechanism of oil generation and overpressure model,which indicate the oil generation of the source rocks with type I kerogens can cause the strong overpressure and is one of the dominant overpressure mechanism in petroliferous basinsThe excellent correlation between the measured overpressure during the physical simulation and the calculated values indicate that the oil generated overpressure model can be used to quantitative estimation of overpressure caused by oil generationThe oil generated overpressure is affected by the source rock maturity,TOC contents,hydrogen index,the oil residual coefficient(α) and so onThe sensitive analysis of the parameters in the overpressure model suggest that the oil residual coefficient(α) is the most sensitive to the overpressure caused by the oil generation among the source rock TOC contents,hydrogen index and oil residual coefficient(α),the hydrogen index is the least sensitiveOverpressure can not generate before hydrocarbon expulsion if oil residual coefficient(α) is less 075,however,strong overpressure can appear if the source rock TOC contents is only 05% with a good pressure seal

12 citations

19 May 2006
TL;DR: A probabilistic risk assessment (PRA) approach has been developed and applied to the risk analysis of capsule abort during ascent as discussed by the authors, which is used to assist in the identification of modeling and simulation applications that can significantly impact the understanding of crew risk during this potentially dangerous maneuver.
Abstract: A probabilistic risk assessment (PRA) approach has been developed and applied to the risk analysis of capsule abort during ascent The PRA is used to assist in the identification of modeling and simulation applications that can significantly impact the understanding of crew risk during this potentially dangerous maneuver The PRA approach is also being used to identify the appropriate level of fidelity for the modeling of those critical failure modes The Apollo launch escape system (LES) was chosen as a test problem for application of this approach Failure modes that have been modeled and/or simulated to date include explosive overpressure-based failure, explosive fragment-based failure, land landing failures (range limits exceeded either near launch or Mode III trajectories ending on the African continent), capsule-booster re-contact during separation, and failure due to plume-induced instability These failure modes have been investigated using analysis tools in a variety of technical disciplines at various levels of fidelity The current paper focuses on the development and application of a blast overpressure model for the prediction of structural failure due to overpressure, including the application of high-fidelity analysis to predict near-field and headwinds effects

12 citations

Journal ArticleDOI
TL;DR: In this article, the authors considered trinitrotoluene explosive as the standard charge for estimating the peak overpressure and impulse of a trinitro-lucene explosive.
Abstract: Peak overpressure and impulse are the most important parameters in the explosive performance estimation. Available models commonly consider trinitrotoluene explosive as the standard charge. In this...

12 citations

Journal ArticleDOI
TL;DR: In this article, an inverse model is proposed to calculate overpressure due to disequilibrium compaction and aquathermal pressuring, and the model output provides estimates of surface porosity, compaction factor, intrinsic permeability at surface conditions, and a parameter controlling the evolution of the intrinsic porosity with porosity.
Abstract: SUMMARY Pore pressure above the hydrostatic (overpressure) is common in deep basins. It plays an important role in pore fluid migration, represent a significant drilling hazard, and is one of the factors controlling slope stability and deformation in seismically active areas. Here, we present an inverse model to calculate overpressure due to disequilibrium compaction and aquathermal pressuring. We minimize a function that contains the misfits between estimates from our forward model and observed values using a non-linear least squares approach. The inverse model allows the introduction of observed seismic and geological constraints such as P-wave velocity (Vp) and density data, and depth of the layer boundaries, for a better pore-pressure prediction. The model output also provides estimates of: (1) surface porosity, (2) compaction factor, (3) intrinsic permeability at surface conditions, (4) a parameter controlling the evolution of the intrinsic permeability with porosity, (5) the ratio between horizontal and vertical permeability and (6) uncompacted thickness (so sedimentation rate assuming known time intervals), for each sedimentary layer. We apply our inverse approach to the centre of the Eastern Black Sea Basin (EBSB) where the Vp structure has been inferred from wide-angle seismic data. First, we present results from a 1-D inverse model and an uncertainty analysis based on the Monte Carlo error propagation technique. To represent the observed rapid change from low Vp to normal Vp below the Maikop formation, we impose a zero overpressure bottom boundary, and subdivide the layer below the Maikop formation into two sublayers: an upper layer where the rapid change is located and a lower layer where the Vp is normal. Secondly, we present the results from a 2-D inverse model for the same layers using two alternative bottom boundary conditions, zero overpressure and zero flow. We are able to simulatetheobserved Vp,suggestingthatthelowvelocityzone(LVZ)at ∼3500–6500mdepth below the seabed (mbsf) can be explained by overpressure generated due to disequilibrium compaction (>90 per cent) and to aquathermal pressuring (<10 per cent). Our results suggest thattheuppersublayer,belowtheMaikopformation,behavesasasealduetoitslowpermeability ∼0.3–2 × 10 −14 ms –1 . This seal layer does not allow the fluids to escape downwards, and hence overpressure develops in the Maikop formation and not in the layers below. This overpressure was mainly generated by the relatively high sedimentation rate of ∼0.29 m ka –1 of the Maikop formation at 33.9–20.5Ma and an even higher sedimentation rate of ∼0.93 m ka –1 at 13–11 Ma. We estimate a maximum ratio of overpressure to vertical effective stress in hydrostatic conditions (λ ∗ )o f∼0.62 at ∼5200 mbsf associated with an overpressure

12 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023263
2022504
2021174
2020173
2019171
2018174