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Tungsten 2025年第1期7卷 120-136页

作者： Zao-Ming Wu Lin He Lin-Sen Ye Xiao-Feng Yang jia-jia zhang Hong-Bo Lei Institute of Materials China Academy of Engineering Physics

High-density uniform microstructure nanocrystalline W-10wt.% Cr-5wt.% Y（W-10Cr-5Y） alloy with an average grain size of 85 nm and a relative density of 99.8% was successfully prepared.W-Cr-Y alloys with different amounts of second-phase particles were prepared by high-energy ball milling and hot isostatic pressing *** effects of composition design,ball milling parameters,and sintering parameters on the microstructure of W-Cr-Y alloys were studied.A feasible technology for controlling the synthesis of high-density nanocrystalline W-based alloys has been *** microstructure analysis of nanocrystalline W-10Cr-5Y alloy shows that there are two types of doping in the second phase:intergranular doping and intragranular *** "uniform distribution YOx-rich particles" effectively suppresses the grain growth of W and leads to the formation of nanocrystalline W-10Cr-5Y alloy.W-10Cr-5Y has an ultra-high hardness,with a Vickers hardness of 1312±12 kgf·***-temperature annealing treatment shows that W-10Cr-5Y has good thermal stability at 1000 and1100℃,as demonstrated by the comparison of Vickers hardness and grain size between annealed and unannealed alloys.

关键词： Hot isostatic pressing Microstructure Nanocrystalline tungsten Thermal stability Vickers hardness

Robustness of F-Tests in Singular Linear Models

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Acta Mathematica Sinica,English Series 2014年第5期30卷 872-880页

作者： Hong Bing QIU Ji LUO jia jia zhang School of Applied Mathematics Guangdong University of Technology School of Mathematics and Statistics Zhejiang University of Finance and Economics Department of Epidemiology and Biostatistics University of South Carolina

F-test is the most popular test in the general linear model. However, there is few discussions on the robustness of F-test under the singular linear model. In this paper, the necessary and sufficient conditions of robust F-test statistic are given under the general linear models or their partition models, which allows that the design matrix has deficient rank and the covariance matrix of error is a nonnegative definite matrix with parameters. The main results obtained in this paper include the existing findings of the general linear model under the definite covariance matrix. The usage of the theorems is illustrated by an example.

关键词： Linear model F-test robustness maximal class

Azimuthal elastic impedance-based Fourier coefficient variation with angle inversion for fracture weakness

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Petroleum Science 2020年第1期17卷 86-104页

作者： Lin Li jia-jia zhang Xin-Peng Pan Guang-Zhi zhang School of Geosciences China University of Petroleum(East China)Qingdao 266580ShandongChina School of Geoscience and Info-Physics Central South UniversityChangsha 410082HunanChina Laboratory for Marine Mineral Resources Qingdao National Laboratory for Marine Science and TechnologyQingdao 266071ShandongChina

Quantitative inversion of fracture weakness plays an important role in fracture *** reservoirs with a set of vertical fractures as horizontal transversely isotropic media,the logarithmic normalized azimuthal elastic impedance(EI)is rewritten in terms of Fourier coefficients(FCs),the 90°ambiguity in the azimuth estimation of the symmetry axis is resolved by judging the sign of the second FC,and we choose the FCs with the highest sensitivity to fracture weakness and present a feasible inversion workflow for fracture weakness,which involves:(1)the inversion for azimuthal EI datasets from observed azimuthal angle gathers;(2)the prediction for the second FCs and azimuth of the symmetry axis from the estimated azimuthal EI datasets;and(3)the estimation of fracture weakness combining the extracted second FCs and azimuth of the symmetry axis iteratively,which is constrained utilizing the Cauchy sparse regularization and the low-frequency regularization in a Bayesian *** on synthetic and field data demonstrate that the 90°ambiguity in the azimuth estimation of the symmetry axis has been removed,and reliable fracture weakness can be obtained when the estimated azimuth of the symmetry axis deviates less than 30°,which can guide the prediction of fractured reservoirs.

关键词： Fracture weakness Azimuth of the symmetry axis Azimuthal Fourier coefficients HTI Azimuthal elastic impedance

Zoeppritz-based AVO inversion using an improved Markov chain Monte Carlo method

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Petroleum Science 2017年第1期14卷 75-83页

作者： Xin-Peng Pan Guang-Zhi zhang jia-jia zhang Xing-Yao Yin School of Geosciences China University of Petroleum(Huadong) Laboratory for Marine Mineral Resources Qingdao National Laboratory for Marine Science and Technology

The conventional Markov chain Monte Carlo （MCMC） method is limited to the selected shape and size of proposal distribution and is not easy to start when the initial proposal distribution is far away from the target distribution. To overcome these drawbacks of the conventional MCMC method, two useful improvements in MCMC method, adaptive Metropolis （AM） algorithm and delayed rejection （DR） algorithm, are attempted to be combined. The AM algorithm aims at adapting the proposal distribution by using the generated estimators, and the DR algorithm aims at enhancing the efficiency of the improved MCMC method. Based on the improved MCMC method, a Bayesian amplitude versus offset （AVO） inversion method on the basis of the exact Zoeppritz equation has been developed, with which the P- and S-wave velocities and the density can be obtained directly, and the uncertainty of AVO inversion results has been estimated as well. The study based on the logging data and the seismic data demonstrates the feasibility and robustness of the method and shows that all three parameters are well retrieved. So the exact Zoeppritz-based nonlinear inversion method by using the improved MCMC is not only suitable for reservoirs with strong-contrast interfaces and longoffset ranges but also it is more stable, accurate and antinoise.

关键词： Adaptive Metropolis (AM) algorithm Delayed rejection (DR) algorithm Bayesian AVOinversion Exact Zoeppritz Nonlinear inversion

Estimation of fracture density and orientation from azimuthal elastic impedance difference through singular value decomposition

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Petroleum Science 2021年第6期18卷 1675-1688页

作者： Lin Li Guang-Zhi zhang Jun-Zhou Liu Lei Han jia-jia zhang School of Geosciences China University of Petroleum(East China)QingdaoShandong 266580China Sinopec Exploration and Production Research Institute Beijing100083China

Accurate estimation of fracture density and orientation is of great significance for seismic characterization of fractured ***,we propose a novel methodology to estimate fracture density and orientation from azimuthal elastic impedance(AEI)difference using singular value decomposition(SVD).Based on Hudson's model,we first derive the AEI equation containing fracture density in HTI media,and then obtain basis functions and singular values from the normalized AEI difference utilizing *** shows that the basis function changing with azimuth is related to fracture orientation,fracture density is the linearly weighted sum of singular values,and the first singular value contributes the most to fracture ***,we develop an SVD-based fracture density and orientation inversion approach constrained by smooth prior elastic *** example shows that fracture density and orientation can be stably estimated,and the correlation coefficient between the true value and the estimated fracture density is above 0.85 even when an S/N ratio of *** data example shows that the estimated fracture orientation is consistent with the interpretation of image log data,and the estimated fracture density reliably indicates fractured gas-bearing reservoir,which could help to guide the exploration and development of fractured reservoirs.

关键词： Singular value decomposition HTI media Azimuthal elastic impedance inversion Fracture density Fracture orientation

Vertical grain-size trend of mouth bar in lacustrine fan delta:Flume experiments

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Petroleum Science 2022年第5期19卷 1964-1977页

作者： Ke zhang Sheng-He Wu Jun-Jie Wang Yun-Jie Xu Zhen-Hua Xu jia-jia zhang State Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum(Beijing)Beijing102249China College of Geosciences China University of Petroleum(Beijing)Beijing102249China School of Geosciences Yangtze UniversityWuhanHubei 430100China

Field observational previously indicated a mouth bar of a fan delta could exhibit a fining-or coarseningupward trend,which bring a new challenge to the identification of mouth bar in subsurface studies due to the lack of morphological *** studies have indicated that effluent behavior in rivermouth system can affect the vertical grain-size trend of mouth bar,but the drivers and magnitude of this phenomenon are not *** conducted flume experiments to investigate the mechanism and controlling factors of vertical grain-size trend of mouth *** with a steeper slope of the substrate layer,greater discharge,higher sediment/water ratio,and coarser sediment induced a finingupward trend of mouth bar,because the effluent was dominated by strong *** bar in the experiment with a gentler slope of the substrate layer,smaller discharge,lower sediment/water ratio,and finer sediment exhibited a coarsening-upward trend dominated by the friction-dominated *** relationship between the vertical grain-size trend of mouth bar and the gradients of foreset bedding in small-scale flume models and the cut-off of 15°-18°are applicable in natural *** depositional setting to infer depositional process in river-mouth system and analyzing the plane geometry of sandbodies are two steps in the interpretation of ancient fan deltaic rock record.

关键词： Mouth bar Vertical grain-size trend Effluent behavior Inertia Bed friction

A two-step method to apply Xu–Payne multi-porosity model to estimate pore type from seismic data for carbonate reservoirs

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Petroleum Science 2020年第3期17卷 615-627页

作者： Hong-Bing Li jia-jia zhang Sheng-Juan Cai Hao-Jie Pan Research Institute of Petroleum Exploration and Development Petrochina Company LimitedBeijing 100083China School of Geosciences China University of Petroleum(East China)Qingdao 266580China

Carbonate reservoirs exhibit strong heterogeneity in the distribution of pore types that can be quantitatively characterized by applying Xu–Payne multi-porosity ***,there are some prerequisites to this model the porosity and saturation need to be *** general,these application conditions are difficult to satisfy for seismic *** order to overcome this problem,we present a two-step method to estimate the porosity and saturation and pore type of carbonate reservoirs from seismic *** step one,the pore space of the carbonate reservoir is equivalent to a single-porosity system with an effective pore aspect ratio;then,a 3D rock-physics template(RPT)is established through the Gassmann’s equations and effective medium models;and then,the effective aspect ratio of pore,porosity and fluid saturation are simultaneously estimated from the seismic data based on 3D *** step two,the pore space of the carbonate reservoir is equivalent to a triple-porosity *** with the inverted porosity and saturation in the first step,the porosities of three pore types can be inverted from the seismic elastic *** application results indicate that our method can obtain accurate physical properties consistent with logging data and ensure the reliability of characterization of pore type.

关键词： Carbonate reservoirs Pore type Physical properties Rock-physics modeling Rock-physics inversion

First-order multiples imaging aided by water bottom

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Petroleum Science 2021年第6期18卷 1650-1661页

作者： Zhen-Hua Xu Sheng-He Wu Ming-Cheng Liu Jun-Shou Zhao Zhao-Hui Chen Ke zhang jia-jia zhang Zhao Liu State Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum-BeijingBeijing 102249China College of Geosciences China University of Petroleum-BeijingBeijing102249China Bohai Petroleum Research Institute CNOOC Tianjin BranchTianjin300459China Sinopec Geophysical Research Institute NanjingJiangsu211103China

Surface-related multiples frequently propagate into the subsurface and contain abundant information on small reflection *** with the conventional migration of primaries,migration of multiples offers complementary illumination and a higher vertical ***,crosstalk artifacts caused by unrelated multiples during reverse time migration(RTM)using multiples severely degrade the reliability and interpretation of the final migration ***,we proposed RTM using first-order receiver-side water-bottom-related multiples for eliminating crosstalk artifacts and enhancing vertical *** first backward propagate the first-order receiver-side water-bottom-related multiples using a water-layer model,followed by saving the upper boundary *** we produce the source wavefield using a seismic wavelet and the receiver wavefield by back-extrapolating the saved ***,the cross-correlation imaging condition is applied to generate the final *** method transforms the receiver-side multiples into primaries,followed by the conventional migration processing *** examples using synthetic datasets demonstrate that our method significantly enhances the imaging quality by eliminating crosstalk artifacts and improving the resolution.

关键词： Surface-related multiples Multiples imaging Multiples elimination

Effects of water discharge on river-dominated delta growth

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Petroleum Science 2021年第6期18卷 1630-1649页

作者： Yan-Bao zhang Yi-Ke Liu jia Yi Xue-jian Liu Institute of Geophysics China Earthquake AdministrationBeijing100081China Key Laboratory of Petroleum Resources Research Institute of Geology and GeophysicsChinese Academy of SciencesBeijing100029China China Earthquake Disaster Prevention Center China Earthquake AdministrationBeijing100029China The Pennsylvania State University Department of GeosciencesUniversity ParkPA16802USA

River-dominated deltas are commonly developed at modern bays and lakes and ancient petroliferous *** discharge is an important variable at pay zone scales in river-dominated delta reservoirs,which affects deltaic sand distributions and ***,it's unclear how it influences riverdominated delta *** paper integrates Delft3 D simulations and modern analogs to analyze the effects of water discharge,considering growth time,sediment supply,and coupled effects of sediment *** water discharges lead to the formation of lobate deltas,and the water discharge of 1,000 m~3/s is a referenced threshold ***-grained,highly-cohesive sediments increase the threshold values of water discharge at which the deltas become lobate from digitate,and vice *** the same simulation time,high water discharges favor more rugose shorelines,more distributary channels(especially secondary distributaries),and longer and wider deltas with more land ***,for the same sediment supply,high water discharges have few effects on shoreline roughness and the number of distributary channels.

关键词： River-dominated delta Water discharge Morphology Distributary channel Hydrocarbon exploration

Sedimentary architecture of submarine channel-lobe systems under different seafloor topography:Insights from the Rovuma Basin offshore East Africa

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Petroleum Science 2024年第1期21卷 125-142页

作者： Mei Chen Sheng-He Wu Rui-Feng Wang jia-jia zhang Peng-Fei Xie Min Wang Xiao-Feng Wang Ji-Tao Yu Qi-Cong Xiong State Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum(Beijing)Beijing102249China College of Geosciences China University of Petroleum(Beijing)Beijing102249China Faculty of Geosciences University of BremenBremen28359Germany MARUM-Center for Marine and Environmental Sciences University of BremenBremen28359Germany Research institute of Petroleum Exploration and Development PetroChinaBeijing10083China School of Geosciences Yangtze UniversityWuhan 100083HubeiChina CNODC Mozambique Ltd. Beijing 100034China

Seafloor topography plays an important role in the evolution of submarine ***,it is still not so clear how the shape of slope affects the three-dimensional(3-D)architecture of submarine *** this study,we analyze the effect of topography factors on different hierarchical lobe architectures that formed during Pliocene to Quaternary in the Rovuma Basin offshore East *** characterize the shape,size and growth pattern of different hierarchical lobe architectures using 3-D seismic *** find that the relief of the topographic slope determines the location of preferential deposition of lobe complexes and single *** the topography is irregular and presents topographic lows,lobe complexes first infill these *** lobes are deposited preferentially at positions with higher longitudinal(***-slope)slope *** the longitudinal slope becomes higher,the aspect ratio of the single lobes ***(***-slope)topography does not seem to have a strong influence on the shape of single lobe,but it seems to affect the overlap of single *** the lateral slope gradient is relatively high,the single lobes tend to have a larger overlap ***,as the average of lateral slope and longitudinal slope gets greater,the width/thickness ratio of the single lobe is smaller,*** tend to accumulate *** results demonstrate that the shape of slopes more comprehensively influences the 3-D architecture of lobes in natural deep-sea systems than previously other lobe deposits and analogue experiments,which helps us better understand the development and evolution of the distal parts of turbidite systems.

关键词： Submarine fan Seafloor topography Sedimentary architecture Slope system SW Indian ocean