鲍林(L.Pauling)在谈到共振论概念的将来发展和应用时说过:“共振概念在过去三十年中的应用主要是定性的。这仅仅是第一步;随着这一步,应当是具有定量意义的更细微的处理”。岁月流逝,共振论至今五十年,它的发展,它的定量化的情况如何?...鲍林(L.Pauling)在谈到共振论概念的将来发展和应用时说过:“共振概念在过去三十年中的应用主要是定性的。这仅仅是第一步;随着这一步,应当是具有定量意义的更细微的处理”。岁月流逝,共振论至今五十年,它的发展,它的定量化的情况如何?近年来许多学者发现,根据共振论的基本概念,可以用十分简捷的算术方法,得到复杂有机分子的参数,如共振能、键序等、其精确性远远超过简单分子轨道法,而达到高级分子轨道法的精度,属于 VB 范畴的共振论与 MO 法计算结果的高度一致性。展开更多
By analyzing hundreds of capillary pressure curves, the controlling factors of shape and type of capillary pressure curves are found and a novel method is presented to construct capillary pressure curves by using rese...By analyzing hundreds of capillary pressure curves, the controlling factors of shape and type of capillary pressure curves are found and a novel method is presented to construct capillary pressure curves by using reservoir permeability and a synthesized index. The accuracy of this new method is verified by mercury-injection experiments. Considering the limited quantity of capillary pressure data, a new method is developed to extract the Swanson parameter from the NMR T2 distribution and estimate reservoir permeability. Integrating with NMR total porosity, reservoir capillary pressure curves can be constructed to evaluate reservoir pore structure in the intervals with NMR log data. An in-situ example of evaluating reservoir pore structure using the capillary pressure curves by this new method is presented. The result shows that it accurately detects the change in reservoir pore structure as a function of depth.展开更多
The traditional reservoir classification methods based on conventional well logging are inefficient for determining the properties,such as the porosity,shale volume,J function,and flow zone index,of the tight sandston...The traditional reservoir classification methods based on conventional well logging are inefficient for determining the properties,such as the porosity,shale volume,J function,and flow zone index,of the tight sandstone reservoirs because of their complex pore structure and large heterogeneity.Specifically,the method that is commonly used to characterize the reservoir pore structure is dependent on the nuclear magnetic resonance(NMR)transverse relaxation time(T2)distribution,which is closely related to the pore size distribution.Further,the pore structure parameters(displacement pressure,maximum pore-throat radius,and median pore-throat radius)can be determined and applied to reservoir classification based on the empirical linear or power function obtained from the NMR T2 distributions and the mercury intrusion capillary pressure ourves.However,the effective generalization of these empirical functions is difficult because they differ according to the region and are limited by the representative samples of different regions.A lognormal distribution is commonly used to describe the pore size and particle size distributions of the rock and quantitatively characterize the reservoir pore structure based on the volume,mean radius,and standard deviation of the small and large pores.In this study,we obtain six parameters(the volume,mean radius,and standard deviation of the small and large pores)that represent the characteristics of pore distribution and rock heterogeneity,calculate the total porosity via NMR logging,and classify the reservoirs via cluster analysis by adopting a bimodal lognormal distribution to fit the NMR T2 spectrum.Finally,based on the data obtained from the core tests and the NMR logs,the proposed method,which is readily applicable,can effectively classify the tight sandstone reservoirs.展开更多
Based on a simple nonrelativistic constituent quark model, the nucleon structure function F<SUB>2</SUB> in the resonance region is estimated by taking the contributions from low-lying nucleon resonances in...Based on a simple nonrelativistic constituent quark model, the nucleon structure function F<SUB>2</SUB> in the resonance region is estimated by taking the contributions from low-lying nucleon resonances into account. Calculated results are employed to study quark-hardon duality in the nucleon electron scattering process by comparing them to the scaling behavior from the data in deep inelastic scattering region.展开更多
文摘鲍林(L.Pauling)在谈到共振论概念的将来发展和应用时说过:“共振概念在过去三十年中的应用主要是定性的。这仅仅是第一步;随着这一步,应当是具有定量意义的更细微的处理”。岁月流逝,共振论至今五十年,它的发展,它的定量化的情况如何?近年来许多学者发现,根据共振论的基本概念,可以用十分简捷的算术方法,得到复杂有机分子的参数,如共振能、键序等、其精确性远远超过简单分子轨道法,而达到高级分子轨道法的精度,属于 VB 范畴的共振论与 MO 法计算结果的高度一致性。
文摘By analyzing hundreds of capillary pressure curves, the controlling factors of shape and type of capillary pressure curves are found and a novel method is presented to construct capillary pressure curves by using reservoir permeability and a synthesized index. The accuracy of this new method is verified by mercury-injection experiments. Considering the limited quantity of capillary pressure data, a new method is developed to extract the Swanson parameter from the NMR T2 distribution and estimate reservoir permeability. Integrating with NMR total porosity, reservoir capillary pressure curves can be constructed to evaluate reservoir pore structure in the intervals with NMR log data. An in-situ example of evaluating reservoir pore structure using the capillary pressure curves by this new method is presented. The result shows that it accurately detects the change in reservoir pore structure as a function of depth.
基金supported by the by the National Science and Technology Major Project “Prediction Technique and Evaluation of Tight Oil Sweet Spot”(2016ZX05046-002)
文摘The traditional reservoir classification methods based on conventional well logging are inefficient for determining the properties,such as the porosity,shale volume,J function,and flow zone index,of the tight sandstone reservoirs because of their complex pore structure and large heterogeneity.Specifically,the method that is commonly used to characterize the reservoir pore structure is dependent on the nuclear magnetic resonance(NMR)transverse relaxation time(T2)distribution,which is closely related to the pore size distribution.Further,the pore structure parameters(displacement pressure,maximum pore-throat radius,and median pore-throat radius)can be determined and applied to reservoir classification based on the empirical linear or power function obtained from the NMR T2 distributions and the mercury intrusion capillary pressure ourves.However,the effective generalization of these empirical functions is difficult because they differ according to the region and are limited by the representative samples of different regions.A lognormal distribution is commonly used to describe the pore size and particle size distributions of the rock and quantitatively characterize the reservoir pore structure based on the volume,mean radius,and standard deviation of the small and large pores.In this study,we obtain six parameters(the volume,mean radius,and standard deviation of the small and large pores)that represent the characteristics of pore distribution and rock heterogeneity,calculate the total porosity via NMR logging,and classify the reservoirs via cluster analysis by adopting a bimodal lognormal distribution to fit the NMR T2 spectrum.Finally,based on the data obtained from the core tests and the NMR logs,the proposed method,which is readily applicable,can effectively classify the tight sandstone reservoirs.
文摘Based on a simple nonrelativistic constituent quark model, the nucleon structure function F<SUB>2</SUB> in the resonance region is estimated by taking the contributions from low-lying nucleon resonances into account. Calculated results are employed to study quark-hardon duality in the nucleon electron scattering process by comparing them to the scaling behavior from the data in deep inelastic scattering region.