期刊文献+
共找到2,156篇文章
< 1 2 108 >
每页显示 20 50 100
Characterization of reservoir properties and pore structure based on micro-resistivity imaging logging: Porosity spectrum, permeability spectrum, and equivalent capillary pressure curve
1
作者 TIAN Jie WANG Liang +2 位作者 SIMA Liqiang FANG Shi LIU Hongqi 《Petroleum Exploration and Development》 SCIE 2023年第3期628-637,共10页
According to the capillary theory,an equivalent capillary model of micro-resistivity imaging logging was built.On this basis,the theoretical models of porosity spectrum(Ф_(i)),permeability spectrum(K_(i))and equivale... According to the capillary theory,an equivalent capillary model of micro-resistivity imaging logging was built.On this basis,the theoretical models of porosity spectrum(Ф_(i)),permeability spectrum(K_(i))and equivalent capillary pressure curve(pe)were established to reflect the reservoir heterogeneity.To promote the application of the theoretical models,the Archie's equation was introduced to establish a general model for quantitatively characterizing bi,K,and pei.Compared with the existing models,it is shown that:(1)the existing porosity spectrum model is the same as the general equation of gi;(2)the Ki model can display the permeability spectrum as compared with Purcell's permeability model;(3)the per model is constructed on a theoretical basis and avoids the limitations of existing models that are built only based on the component of porosity spectrum,as compared with the empirical model of capillary pressure curve.The application in the Permian Maokou Formation of Well TsX in the Central Sichuan paleo-uplift shows that the Ф_(i),K_(i),and p_(ci) models can be effectively applied to the identification of reservoir types,calculation of reservoir properties and pore structure parameters,and evaluation of reservoir heterogeneity. 展开更多
关键词 micro-resistivity imaging logging pore structure Archie's equation porosity spectrum permeability spectrum capillary pressure curve Sichuan Basin Permian Maokou Formation
下载PDF
Regional plantar foot pressure distributions on high-heeled shoes-shank curve effects 被引量:2
2
作者 Winson Lee 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2011年第6期1091-1097,共7页
Forefoot pain is common in high-heeled shoe wearers due to the high pressure caused by the center of body mass moving forward and the increased arch height with heel elevation.Sufficient arch support could reduce the ... Forefoot pain is common in high-heeled shoe wearers due to the high pressure caused by the center of body mass moving forward and the increased arch height with heel elevation.Sufficient arch support could reduce the high pressure over forefoot.However,too much arch support could lead to abnormal foot alignment and pain over midfoot.Little information is reported on the relationship among plantar arch height,shank curve design and plantar pressure.This study aimed at quantifying the plantar arch height changes at different heel heights and investigating the effect of shank curve on plantar pressure distribution.The plantar arch height increased to(7.6±1.3) mm at heel height of 75 mm.The Chinese standard suggests the depth of last should be 8.5 mm for heel height of 75 mm.When a shank curve with higher depth of last(11 mm) was used,the peak pressure over forefoot further decreased in midstance phase,which might ease the forefoot problems,while the peak pressure over midfoot increased but not exceeded the discomfort pressure thresholds.To achieve a more ideal pressure distribution in high-heeled shoes,a higher than expected depth of last would be suggested that would not cause discomfort over midfoot. 展开更多
关键词 High-heeled shoes Shank curve Plantar archheight Plantar pressure Foot biomechanics
下载PDF
Effects of sample dimensions and shapes on measuring soil-water characteristic curves using pressure plate 被引量:8
3
作者 Min Wang Lingwei Kong Meng Zang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2015年第4期463-468,共6页
It is well known that soilewater characteristic curve (SWCC) plays an important role in unsaturated soil mechanics, but the measurement of SWCC is inconvenient. In laboratory it requires days of testing time. For fi... It is well known that soilewater characteristic curve (SWCC) plays an important role in unsaturated soil mechanics, but the measurement of SWCC is inconvenient. In laboratory it requires days of testing time. For fine-grained clays, it may last for a couple of months using pressure plate tests. In this study, the effects of sample dimensions and shapes on the balance time of measuring SWCCs using pressure plate tests and the shape of SWCCs are investigated. It can be found that the sample dimensions and shapes have apparent influence on the balance time. The testing durations for circular samples with smaller diameters and annular samples with larger contact area are significantly shortened. However, there is little effect of sample dimensions and shapes on the shape of SWCCs. Its mechanism is explored and discussed in details through analysing the principle of pressure plate tests and microstructure of the sample. Based on the above findings, it is found that the circular samples with smaller dimensions can accelerate the testing duration of SWCC using the pressure plate. 展开更多
关键词 Soil-water characteristic curve (SWCC)pressure plateMercury intrusionMicrostructureExpansive soil
下载PDF
Attenuation-type and failure-type curve models on accumulated pore water pressure in saturated normal consolidated clay 被引量:1
4
作者 赵春彦 《Journal of Central South University》 SCIE EI CAS 2012年第7期2047-2053,共7页
Based on dynamic triaxial test results of saturated soft clay, similarities of variations between accumulated pore water pressure and accumulated deformation were analyzed. The Parr's equation on accumulated deformat... Based on dynamic triaxial test results of saturated soft clay, similarities of variations between accumulated pore water pressure and accumulated deformation were analyzed. The Parr's equation on accumulated deformation was modified to create an attenuation-type curve model on accumulated pore water pressure in saturated normal consolidation clay. In this model, dynamic strength was introduced and a new parameter called equivalent dynamic stress level was added. Besides, based on comparative analysis on variations between failure-type and attenuatiun-type curves, a failure-type curve model was created on accumulated pore water pressure in saturated normal consolidation clay. Two models can take cycle number, coupling of static and dynamic deviator stress, and consolidation way into consideration. The models are verified by test results. The correlation coefficients are more than 0.98 for optimization of test results based on the two models, and there is good agreement between the optimized and test curves, which shows that the two models are suitable to predict variations of accumulated pore water pressure under different loading cases and consolidation ways. In order to improve prediction accuracy, it is suggested that loading cases and consolidation ways should be consistent with in-situ conditions when dynamic triaxial tests are used to determine the constants in the models. 展开更多
关键词 saturated normal consolidation clay equivalent dynamic stress level accumulated pore water pressure model attenuation-type curve failure-type curve
下载PDF
An analytical p-y curve method based on compressive soil pressure model in sand soil 被引量:1
5
作者 JIANG Jie FU Chen-zhi +2 位作者 WANG Shun-wei CHEN Chao-qi OU Xiao-duo 《Journal of Central South University》 SCIE EI CAS CSCD 2022年第6期1987-2004,共18页
With the high-quality development of urban buildings,higher requirements are come up with for lateral bearing capacity of laterally loaded piles.Consequently,a more accurate analysis to predict the lateral response of... With the high-quality development of urban buildings,higher requirements are come up with for lateral bearing capacity of laterally loaded piles.Consequently,a more accurate analysis to predict the lateral response of the pile within an allowable displacement is an important issue.However,the current p-y curve methods cannot fully take into account the pile-soil interaction,which will lead to a large calculation difference.In this paper,a new analytical p-y curve is established and a finite difference method for determining the lateral response of pile is proposed,which can consider the separation effect of pile-soil interface and the coefficient of circumferential friction resistance.In particular,an analytical expression is developed to determine the compressive soil pressure by dividing the compressive soil pressure into two parts:initial compressive soil pressure and increment of compressive soil pressure.In addition,the relationship between compressive soil pressure and horizontal displacement of the pile is established based on the reasonable assumption.The correctness of the proposed method is verified through four examples.Based on the verified method,a parametric analysis is also conducted to investigate the influences of factors on lateral response of the pile,including internal friction angle,pile length and elastic modulus of pile. 展开更多
关键词 laterally loaded piles compressive soil pressure model separation effect of pile-soil interface coefficient of circumferential friction resistance analytical p-y curve finite difference method
下载PDF
Pressure Buildup Analysis Using Type Curves for a Well in a Pressure-Maintained System
6
作者 林加恩 杨慧珠 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2007年第1期6-11,共6页
The development and application of a new solution is demonstrated for the type-curve analysis and in-terpretation of well test data from a multiwell reservoir system of both production and injection wells with two-pha... The development and application of a new solution is demonstrated for the type-curve analysis and in-terpretation of well test data from a multiwell reservoir system of both production and injection wells with two-phase flow. The buildup type curves or buildup behavior could be obtained through the solution by using su-perposition. But a new outer boundary condition for variable pressure boundary must be introduced to obtain the correct pressure buildup solutions by superposition. A technique is shown to determine the deviation time from the infinite-acting semilog radial flow stabilization in the derivatives of pressure, which is calculated with respect to and plotted vs. shut-in time. Field examples are given to illustrate the use of the proposed method for analyzing transient pressure data from a well located in a multi-well water-injection reservoir. An adaptive genetic algorithm-based method is used to match the pressure and pressure derivative data to estimate reservoir parameters. The validity and applicability of the proposed method are also demonstrated through the examples. 展开更多
关键词 multi-well reservoir pressure buildup two-phase flow type curve analysis
下载PDF
A new method to construct reservoir capillary pressure curves using NMR log data and its application 被引量:5
7
作者 肖亮 张伟 《Applied Geophysics》 SCIE CSCD 2008年第2期92-98,共7页
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
关键词 NMR log pore structure Swanson parameter synthesized index capillary pressure curves
下载PDF
Determination of volumetric elastic moduli of plant leaf cells based on pressure-volume curves 被引量:1
8
作者 Yanxiang Zhang Quanshui Zheng 《Theoretical & Applied Mechanics Letters》 2012年第1期18-21,共4页
Volumetric elastic modulus (VEM) is an important parameter in biophysics and biomechanics of plants for in particular understanding cell growth. This paper proposes a new relation that can be used for precisely dete... Volumetric elastic modulus (VEM) is an important parameter in biophysics and biomechanics of plants for in particular understanding cell growth. This paper proposes a new relation that can be used for precisely determining VEM. With the aid of this relation, it shows that the exponential approximation of the pressure-volume relationship adopted in most of the literatures in this field may lead to serious errors on VEM. 展开更多
关键词 plant leaf cell volumetric elastic modulus pressure-volume curve
下载PDF
Stability and melting behavior of boron phosphide under high pressure
9
作者 梁文嘉 向晓君 +2 位作者 李倩 梁浩 彭放 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第4期579-584,共6页
Boron phosphide(BP)has gained significant research attention due to its unique photoelectric and mechanical properties.In this work,we investigated the stability of BP under high pressure using x-ray diffraction and s... Boron phosphide(BP)has gained significant research attention due to its unique photoelectric and mechanical properties.In this work,we investigated the stability of BP under high pressure using x-ray diffraction and scanning electron microscope.The phase diagram of BP was explored in both B-rich and P-rich environments,revealing crucial insight into its behavior at 5.0 GPa.Additionally,we measured the melting curve of BP from 8.0 GPa to 15.0 GPa.Our findings indicate that the stability of BP under high pressure is improved within B-rich and P-rich environments.Furthermore,we report a remarkable observation of melting curve frustration at 10.0 GPa.This study will enhance our understanding of stability of BP under high pressure,shedding light on its potential application in semiconductor,thermal,and light-transmitting devices. 展开更多
关键词 boron phosphide STABILITY melting curve high pressure
下载PDF
Pump-stopping pressure drop model considering transient leak-off of fracture network
10
作者 WANG Fei XU Jiaxin +1 位作者 ZHOU Tong ZHANG Shicheng 《Petroleum Exploration and Development》 SCIE 2023年第2期473-483,共11页
By introducing the coupling flow expressions of main fracture-matrix, secondary fracture-matrix and main fracture-secondary fracture into the traditional main fracture material balance equation, the “main fracture-se... By introducing the coupling flow expressions of main fracture-matrix, secondary fracture-matrix and main fracture-secondary fracture into the traditional main fracture material balance equation, the “main fracture-secondary fracture-matrix” leak-off coupling flow model is established. The pressure-dependent fracture width equation and the wellbore injection volume equation are coupled to solve the pressure-rate continuity problem. The simulation and calculation of the bottomhole pressure drop and fracture network closure after the pump stopping in slickwater volumetric fracturing treatment are realized. The research results show that the log-log curve of pump-stopping bottomhole pressure drop derivative presents five characteristic slope segments, reflecting four dominant stages, i.e. inter-fracture crossflow, fracture network leak-off, fracture network closure and residual leak-off, after pump shutdown. At the initial time of pump shutdown for volumetric fracturing treatment of horizontal well, the crossflow between main and secondary fractures is obvious, and then the leak-off becomes dominant. The leak-off of main and secondary fractures shows a non-uniform decreasing trend. Specifically, the leak-off of main fractures is slow, while that of secondary fractures is fast;the fracture network as a whole presents the leak-off law of fast first, then slow, until close to zero. The influence of fracture network conductivity on the shape of pressure decline curve is relatively weaker than that of fracture network size. The fracture network conductivity is positively correlated with leak-off volume and fracture closure. The secondary fracture size is positively correlated with leakoff volume and closure of the secondary fracture, but negatively correlated with closure of the main fracture. Field data validation proves that the proposed model and simulation results can effectively reflect the closure characteristics of the fracture network, and the interpretation results are reliable and can reflect the non-uniform stimulation performance of each fracturing stage of an actual horizontal well. 展开更多
关键词 volume fracturing stop-pumping pressure drop fracture network characteristic curve transient leak-off frac-ture closure stimulation performance
下载PDF
Experimental study on pressure fluctuation characteristics of slug flow in horizontal curved tubes 被引量:1
11
作者 邓志安 Xiao Xue 《High Technology Letters》 EI CAS 2017年第1期23-29,共7页
In order to study the pressure characteristics of slug flow in horizontal curved tubes,two kinds of curved tubes with central angle 45° and 90° respectively are studied,of which are with 0. 5m circumference ... In order to study the pressure characteristics of slug flow in horizontal curved tubes,two kinds of curved tubes with central angle 45° and 90° respectively are studied,of which are with 0. 5m circumference and 26 mm inner diameter are used. When the superficial liquid velocity or the superficial gas velocity is constant,the pressure fluctuations and the probability distribution of the average velocity of slug flow are clear for all of the five experimental conditions. The results of experiment show that the pressure characteristics of slug flow in curved tubes have periodic fluctuations. With the rise of central angle,the period of pressure fluctuation is more obvious. The system pressure of the slug flow increases with the increasing of superficial liquid/gas velocity. Meanwhile,the probability distribution of pressure signal shows regularity,such as unimodal,bimodal or multimodal. 展开更多
关键词 slug flow horizontal curved tube pressure fluctuations central angle
下载PDF
Shale high pressure isothermal adsorption curve and the production dynamic experiments of gas well 被引量:1
12
作者 DUAN Xianggang HU Zhiming +4 位作者 GAO Shusheng SHEN Rui LIU Huaxun CHANG Jin WANG Lin 《Petroleum Exploration and Development》 2018年第1期127-135,共9页
The high pressure static adsorption curves of shale samples from Silurian Changning-Weiyuan Longmaxi Formation were tested by using high pressure isothermal adsorption equipment.The physical modeling of depletion prod... The high pressure static adsorption curves of shale samples from Silurian Changning-Weiyuan Longmaxi Formation were tested by using high pressure isothermal adsorption equipment.The physical modeling of depletion production was tested on single cores and multi-core series by using self-developed shale gas fluid-solid coupling experiment system.The adsorption and desorption laws were summarized and a high pressure isothermal adsorption model was established.The calculation formula of gas content was corrected,and the producing law of adsorption gas was determined.The study results show that the isothermal adsorption law of the shale reservoir under high pressure was different from the conventional low pressure.The high pressure isothermal adsorption curve had the maximum value in excess adsorption with pressure change,and the corresponding pressure was the critical desorption pressure.The high pressure isothermal curve can be used to evaluate the amount of adsorbed gas and the producing degree of adsorption gas.The high pressure isothermal adsorption model can fit and characterize the high pressure isothermal adsorption law of shale.The modified gas content calculation method can evaluate the gas content and the proportion of adsorbed gas more objectively,and is the theoretical basis of reserve assessment and production decline analysis.The producing degree of adsorption gas is closely related to the pressure,only when the reservoir pressure is lower than the critical desorption pressure,the adsorption gas can be produced effectively.In the process of gas well production,the pressure drop in the near-well area is large,the production of adsorption gas is high;away from the wellbore,the adsorption gas is low in production,or no production. 展开更多
关键词 SHALE high pressure ISOTHERMAL ADSORPTION excess ADSORPTION critical DESORPTION pressure SHALE gas ADSORPTION curve
下载PDF
Fusion curves and thermodynamic properties of carbon tetrachloride,chloroform,bromoform and silicon tetrachloride at pressure up to 3500 MPa
13
作者 朱荣娇 徐伟 +1 位作者 田宜灵 郝纪双 《Chinese Physics B》 SCIE EI CAS CSCD 2008年第3期1088-1093,共6页
The fusion temperature as a function of pressure for carbon tetrachloride, chloroform, bromoform and silicon tetrachloride at pressures up to 3500MPa has been determined. The experimental data were fitted by the equat... The fusion temperature as a function of pressure for carbon tetrachloride, chloroform, bromoform and silicon tetrachloride at pressures up to 3500MPa has been determined. The experimental data were fitted by the equation Tfus=T0(1 + Δp/a1)^a2 exp(-a3Δp) and the changes of the maolar enthalpy and molar internal energy on fusion were calculated using the parameters of the fitted equation. Comparisons with the data from the literature show that the experimental data, parameters of fitted equations, changes of the molar enthalpy and molar internal energy are reliable. 展开更多
关键词 fusion curve molar entropy change molar internal energy change high pressure
下载PDF
Biomagnetic Validation to Skin Level for Blood Pressure Curves and Venous
14
作者 T. Cordova-Fraga Francisco Gómez-Aguilar +6 位作者 T. Bravo-Arellano M. A. Hernández-Gonzalez S. Solorio-Meza H. A. Perez-Olivas M. Sosa-Aquino J. J. Bernal-Alvarado C. R. Contreras-Gaytan 《Open Journal of Applied Sciences》 2012年第3期128-134,共7页
An analysis of the reproducibility from signal record bioelectric heart activity is presented. The measurements were carried out with a recently patented medical device, which one is able to record the curves of press... An analysis of the reproducibility from signal record bioelectric heart activity is presented. The measurements were carried out with a recently patented medical device, which one is able to record the curves of pressure arterial and venous as those obtained using the gold standard technique in these evaluations, the cardiac catheterization technique. The measurements were carried out 15 health subjects and patients;each one was measured 5 times in order to have auto-correlations and correlations of these records. Analysis indicates correlations from 0.9 to 1 as long as p values were below 0.05. It is indicated an excellent reproducibility of evaluated patients. 展开更多
关键词 Bioelectric HEART Activity curveS of pressure ARTERIAL and VENOUS Correlation Coefficient Statistical Analysis
下载PDF
DETERMINATION OF PRESSURIZING CURVE AND COMPUTER CONTROL OF THICKNESS THINNING FOR SUPERPLASTIC BULGING
15
作者 张中元 黄翔 +1 位作者 周建华 王卫英 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 1995年第1期30-38,共9页
This paper proposes the assumption that the flow with viscous friction is the stretch of part of the sheet that lies along the walls of a die during the process of superplastic bulging according to superplastic flow e... This paper proposes the assumption that the flow with viscous friction is the stretch of part of the sheet that lies along the walls of a die during the process of superplastic bulging according to superplastic flow equation and geometrical model of bulging of a sheet into a long trapezoid groove or truncated cone, by introducing the friction-factor P which describes the friction effect on the process. Also, the paper proposes the method of controlling thickness nonuniformity and develops the equipment which for uniform thickness of bulging, is automatically controlled with a computerl it also analyzes the important innuence of lubrication on thickness distribution of bulging materials. By the assumption, the relationship between bulging pressure and time is obtained in bulging of a sheet into the groove and cone, and p-t curve of multi-mould-cavity complicated bulging is discussed based on the analysis of single-mould-cavity bulging characteristics. 展开更多
关键词 superplastic forming computer control friction-factor thinning-rate pressure curve superplastic bulging
下载PDF
基于广义波阻抗理论的SHPB试验中弹性压缩阶段试件应力-应变曲线的应力波效应及其影响机理
16
作者 高光发 《爆炸与冲击》 EI CAS CSCD 北大核心 2024年第9期98-111,共14页
定量研究分离式霍普金森压杆(split Hopkinson pressure bar,SHPB)试验中弹性压缩阶段试件中的应力波效应是解耦准确材料弹性曲线的基础。在满足平面波假设的基础上,基于广义波阻抗理论,对杆与试件面积不匹配时试件弹性压缩阶段应力波... 定量研究分离式霍普金森压杆(split Hopkinson pressure bar,SHPB)试验中弹性压缩阶段试件中的应力波效应是解耦准确材料弹性曲线的基础。在满足平面波假设的基础上,基于广义波阻抗理论,对杆与试件面积不匹配时试件弹性压缩阶段应力波演化造成的结构效应开展了定量理论研究,分析了不同情况下弹性阶段内试件唯象工程及实际材料应力-应变曲线的偏差特征与主要因素,并揭示了影响这种偏差的影响规律及其机理。研究表明:对于线性入射加载波,当无量纲时间为0.5的倍数时,即使其他参数改变,试件唯象与材料实际的应力-应变曲线仍对应相等;试件两端的应力差较大时,若应力差的变化趋于稳定,则试件唯象与材料实际的应力-应变曲线差异较小。计算了不同波动区间内试件的最大应力偏离值及其变化趋势和对应的无量纲时间,研究了入射波是双线性组合波时试件的应力-应变曲线。研究表明:双线性波入射时,2个线性区间可以独立分析,无论如何组合线性区间或应力差如何变化,只要试件两端应力差为近似恒定曲线,对应的试件唯象工程应力-应变曲线都是相对准确的。 展开更多
关键词 分离式霍普金森压杆 应力波效应 应力均匀性假设 动态应力-应变曲线
下载PDF
基于Master Curve方法的A508-Ⅲ钢断裂韧性研究 被引量:5
17
作者 方颖 李辉 +2 位作者 惠虎 贺寅彪 李培宁 《核动力工程》 EI CAS CSCD 北大核心 2011年第S1期31-34,共4页
进行了国产A508-Ⅲ钢在韧脆转变区的拉伸实验和夏比冲击实验,获得了A508-III钢在此区域的力学性能和夏比冲击功随温度的变化曲线。以夏比冲击功为28 J或41 J所对应的特征温度关联预估MasterCurve方法的试验温度,分别采用多温度试验法和... 进行了国产A508-Ⅲ钢在韧脆转变区的拉伸实验和夏比冲击实验,获得了A508-III钢在此区域的力学性能和夏比冲击功随温度的变化曲线。以夏比冲击功为28 J或41 J所对应的特征温度关联预估MasterCurve方法的试验温度,分别采用多温度试验法和单温度试验法获得12.7 mm厚三点弯曲试样[SE(B)试样]的Master Curve曲线,并对其参考温度T0进行有效性判定。结果表明,采用单温度及多温度法获得的T0基本一致,国产A508-Ⅲ钢断裂韧性参考温度约为-63℃。 展开更多
关键词 A508-Ⅲ钢 MASTER curve方法 断裂韧性 韧脆转变 ASMEKIC曲线
下载PDF
基于停泵压降曲线的压裂窜扰效果定量评价--以吉木萨尔页岩油平台井为例
18
作者 王飞 董卓 +3 位作者 徐田录 陈璐 王政凯 李占杰 《新疆石油天然气》 CAS 2024年第3期91-98,共8页
针对目前缺乏压裂窜扰效果定量评价方法的难题,创新提出一套基于停泵压降曲线的压裂窜扰效果诊断分析方法。结合井组拉链式压裂工艺,提出了4种典型窜扰模式下的停泵压降曲线,用以诊断压裂窜扰类型。选取吉木萨尔页岩油A平台6个典型压裂... 针对目前缺乏压裂窜扰效果定量评价方法的难题,创新提出一套基于停泵压降曲线的压裂窜扰效果诊断分析方法。结合井组拉链式压裂工艺,提出了4种典型窜扰模式下的停泵压降曲线,用以诊断压裂窜扰类型。选取吉木萨尔页岩油A平台6个典型压裂窜扰段开展实例应用,通过与微地震监测结果对比,验证了方法的有效性。在此基础上,利用压降试井解释方法对吉木萨尔“新井组内部压窜”和“新老井间压窜”两种典型的停泵压降曲线开展拟合分析,反演解释缝网参数。解释结果表明,新井组内部压窜使主次裂缝的改造效果均受到影响,具体影响效果因窜扰类型的不同而存在差异;新老井间压窜主要影响主裂缝的改造效果,导致缝网由“长宽”向“短窄”转变,有效体积降低28%,整体改造效果变差。 展开更多
关键词 吉木萨尔页岩油 平台井组 压裂窜扰 停泵压降曲线 试井解释
下载PDF
常规压汞-恒速压汞联合曲线构型模式及其指示意义
19
作者 代金友 雷禧桢 +2 位作者 皮莎 沈小述 陈代欣 《新疆石油地质》 CAS CSCD 北大核心 2024年第6期735-741,共7页
利用构型理论和层次分析方法,对常规压汞-恒速压汞联合曲线构型形貌进行划分,建立具有普遍意义的常规压汞-恒速压汞联合曲线三段式构型模式,探讨了该模式对岩石孔喉体系及其润湿滞后特性的指示意义。结果表明:常规压汞-恒速压汞联合曲线... 利用构型理论和层次分析方法,对常规压汞-恒速压汞联合曲线构型形貌进行划分,建立具有普遍意义的常规压汞-恒速压汞联合曲线三段式构型模式,探讨了该模式对岩石孔喉体系及其润湿滞后特性的指示意义。结果表明:常规压汞-恒速压汞联合曲线由a、b和c构型段组成,各构型段相互衔接,形貌各异;a构型段呈重叠形貌,指示了大孔喉体系,常规压汞-恒速压汞联合曲线无润湿滞后特性;b构型段呈分离形貌,可细分为b_(1)和b_(2)构型亚段,b_(1)构型亚段指示了中孔喉体系,恒速压汞曲线无润湿滞后特性,常规压汞曲线有润湿滞后特性,b_(2)构型亚段指示了中孔喉体系,常规压汞-恒速压汞联合曲线关联润湿滞后特性;c构型段呈重叠形貌,指示了小孔喉体系,常规压汞-恒速压汞联合曲线具有同等润湿滞后特性;常规压汞汞弯液面变形集中于b—c构型段,恒速压汞汞弯液面变形集中于b_(2)构型亚段—c构型段;常规压汞曲线和恒速压汞曲线的b_(1)构型亚段可用于接触角校正。常规压汞-恒速压汞联合曲线的三段式构型模式,对分段接触角校正及表征岩石孔喉分布具有重要指导意义。 展开更多
关键词 常规压汞 恒速压汞 毛细管压力曲线 构型模式 孔喉体系 润湿滞后
下载PDF
Comparative study of CEA and CA19-9 in esophageal,gastric and colon cancers individually and in combination(ROC curve analysis) 被引量:56
20
作者 Bhawna Bagaria Sadhna Sood +1 位作者 Rameshwaram Sharma Soniya Lalwani 《Cancer Biology & Medicine》 SCIE CAS CSCD 2013年第3期148-157,共10页
Objective: To determine the clinical serum levels of carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9), individually and in combination, for the diagnosis of 50 healthy subjects and 150 cases ... Objective: To determine the clinical serum levels of carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9), individually and in combination, for the diagnosis of 50 healthy subjects and 150 cases of esophageal, gastric, and colon cancers. Methods: The sensitivities of the two markers were compared individually and in combination, with specificity set at 100%. Receiver operating characteristic (ROC) curves were plotted. Results: Serum CEA levels were significantly higher in cancer patients than in the control group. The sensitivity of CEA was determined: in esophageal cancer, sensitivity=28%, negative predictive value (NPV)=61.72%, and AUC=0.742 (SE=0.05), with a significance level of P〈0.0001; in gastric cancer, sensitivity=30%, NPV=58.82%, and AUC=0.734 (SE=0.0S), with a significance level of P〈0.0001; in colon cancer, sensitivity=74%, NPV=79.36%, and AUC=0.856 (SE=0.04), with a significance level of P〈0.0001. The sensitivity of CA19-9 was also evaluated: in esophageal cancer, sensitivity=18%, NPV=54.94%, and AUC=0.573 (SE=0.05), with a significance level of P=0.2054. In gastric cancer, sensitivity=42%, NPV=63.29%, and AUC=0.679 (SE=0.05), with a significance level of P〈0.0011. In colon cancer, sensitivity=26%, NPV=57.47%, and AUC=0.S80 (SE=0.05), with a significance level ofP=0.1670. The following were the sensitivities of CEA/CA19-9 combined: in esophageal cancer, sensitivity=42%, NPV=63.29%, SE=0.078 (95% CI: 0.0159-0.322); gastric cancer, sensitivity=S8%, NPV=70.42%, SE=0.072 (9$% CI: -0.0866-0.198); and colon cancer, sensitivity=72%, NPV=78.12%, SE=0.070 (9S% CI: 0.137-0.415). Conclusion: CEA exhibited the highest sensitivity for colon cancer, and CA19-9 exhibited the highest sensitivity for gastric cancer. Combined analysis indicated an increase in diagnostic sensitivity in esophageal and gastric cancer compared with that in colon cancer. 展开更多
关键词 Carcinoembryonic antigen carbohydrate antigen 19-9 human Receiver operating characteristic curve sensitivity andspecificity
下载PDF
上一页 1 2 108 下一页 到第
使用帮助 返回顶部