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81.
Relative permeability of CBM reservoirs: Controls on curve shape 总被引:1,自引:0,他引:1
C.R. Clarkson M. Rahmanian A. Kantzas K. Morad 《International Journal of Coal Geology》2011,88(4):204
Relative permeability to gas and water for 2-phase flow coalbed methane (CBM) reservoirs has long been known to exhibit a strong control on (gas and water) production profile characteristics. Despite its important control on both primary and enhanced recovery of CBM for coal seams that have not been fully dewatered, relative permeability in coal has received little attention in the literature in the past decade. There are few published laboratory-derived curves; these studies and their resulting data represent a small subset of the commercial CBM reservoirs and do not allow for a systematic investigation of the physical controls on relative permeability curve shape. Other methods for estimation of relative permeability curves include derivation from simulation history-matching, and production data analysis. Both of these methods will yield pseudo-relative permeability curves whose shapes could be affected by several dynamic CBM reservoir and operating characteristics.The purpose of the current work is to perform a systematic investigation of the controls on CBM relative permeability curve shape, including non-static fracture permeability and porosity, multi-layer effects and transient flow. To derive the relative permeability curves, effective permeability to gas and water are obtained from flow equations, flow rates and pressure data. Simulated cases are analyzed so that derived and input curves may be compared allowing for investigation of CBM reservoir properties on curve shape. One set of relative permeability curves that were input into the simulator were obtained from pore-scale modeling. Field cases from two basins are also examined and controls on derived relative permeability curve shape inferred. The results of this work should be useful for future CBM development and greenhouse gas sequestration studies, and it is hoped that it will spark additional research of this critical CBM flow property. 相似文献
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Nicholas A. Teanby 《Mathematical Geology》2007,39(4):419-434
A method of fitting a smooth cubic spline curve through noisy data points is presented. Overshoots of the spline curve between
data points were prevented by applying tension to the fit using a quadratic spring approximation, which allowed a linear inverse
theory approach to be adopted. Error-bars in the measured data were mapped through the inversion process to give the covariance
of the fitted curve. This is an improvement over previous methods, which largely neglect the effect of data errors on the
fit. Another improvement is to impose fixed constraints on the fit by simultaneously applying the method of Lagrange multipliers.
The effect of these constraints on the covariance of the fitted curve is quantified using results from linear algebra. Example
applications to synthetic data and a record of magnetic inclination from Hawaii are given. 相似文献
85.
采用乌鲁木齐市和其郊区日照时间的差值作为衡量城市"浑浊岛效应"的标准,以乌鲁木齐市城市化九项指标的综合值作为衡量城市化的标准,数据的跨度从1976—2004年;对这两列数值进行相关分析。文章的结论包括:城市化与"城市浑浊岛"效应有很强的相关性;城市化对城市浑浊岛的影响分3个阶段;乌鲁木齐市的浑浊岛效应符合环境库兹涅茨规律。 相似文献
86.
基于RS和GIS的中尺度流域土地利用空间结构变化——以伊洛河流域中部洛宁县为例 总被引:5,自引:0,他引:5
选择伊洛河流域中部洛宁县为研究区域 ,运用RS和GIS技术 ,分别提取研究区 1 987和 1 999年以地貌类型为单元的土地利用数据绘制罗伦兹曲线。结果表明 :1 987~ 1 999年 ,各地类在各类地貌单元的集中与分散程度的整体状况未发生变化 ,其分布的集中程度依次为建设用地 >水域 >林地 >耕地 >未利用土地 ;但集中和分散程度发生明显变化 ,其中林地分布趋于集中 ,耕地、水域和未利用土地趋于分散 ,而建设用地基本没有变化 ,其原因主要是该时段川涧区林地大幅度增加 ,而其它地貌单元林地面积大量减少所致 相似文献
87.
人口预测方法及可靠性探讨 总被引:10,自引:1,他引:10
运用曲线拟合和灰色系统理论对我国人口发展进行预测,并对预测结果进行可靠性检验。 相似文献
88.
黄河中游区水,沙变化趋势及其预测 总被引:2,自引:0,他引:2
本文用灰色系统分析方法对黄河中游区干、支流主要测站水、沙资料进行研究、评估,阐明了水、沙多年变化趋势,论证了水、沙多年变化的原因,并对几个测站试作水、沙长期预测。 相似文献
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90.
James V. Bonta 《国际泥沙研究》2000,(2)
1INTRODUCTIONSediment-yieldestimatesarerequiredforsurfacec0al-minepermitsunderFederalandStatelaws-Estimatesareneededfordeterminingtheimpactsofminingandreclamationduringmine0Peration,fordiversi0nandsmallimpoundmentdesigns,andforsizingsedimentpondstocontrolsedimenttransporteddownstfeam0faproposedminesite.Technologiesavailablef0rsediment-yieldestimationsincludetheUniversalSoilLossEquati0n(USLE,WischmierandSmith,l978);theWaterErosionPredictionPr0ject(WEPP,FlanaganandLivingst0n,l995),… 相似文献