岩石储集物性的核磁共振技术研究

在实验室条件下利用Meso MR23-060H型低场核磁共振岩心分析仪以及岩心核磁共振解释分析软件对贵州各类岩性的大量岩心开展了岩心核磁孔隙度、渗透率、束缚流体饱和度实验研究,总结建立了贵州岩石核磁孔隙度、渗透率、束缚水饱和度等的储层参数的解释模型。实验研究了顺磁离子对岩石核磁响应的影响,对比了岩屑与完整岩心的核磁响应,表明利用岩屑也可以实现岩石孔渗参数的测量。     

井楼稠油高温蒸汽吞吐含水饱和度的求取研究

本文以井楼油田稠油岩心实验分析资料为基础,应用岩心刻度测井的方法,建立了稠油储层孔隙度、渗透率和饱和度测井解释模型;通过稠油岩心高温水驱实验,建立了高温蒸汽吞吐下的饱和度解释模型;并根据介电测井、碳氧比测井技术,建立了特殊测井技术下的稠油高温蒸汽吞吐下的饱和度模型。为油田后期编制开发方案、增储上产提供了坚实的物质基础。     

低渗砂岩气层岩石电性实验研究

含水饱和度对岩石电阻率、饱和度指数以及地层因素有重要影响,这些参数是利用电测井资料评价含气饱和度的重要参数.测量储层不同含水饱和度岩石的电性,对于研究储层原始含气饱和度、气层分布和综合评价含气性具有重要意义.本文通过室内实验研究了不同岩性、渗透率的岩心在不同含水饱和度条件下岩心电阻率的变化,分析了岩心含水饱和度的变化对低渗岩石电阻率和饱和度指数以及地层因素的影响.     

基于数字岩心的砂岩核磁共振测井响应特征分析

核磁共振测井在计算储层流体饱和度、孔隙度、孔隙结构及渗透率方面发挥着重要作用,本文通过过程法建立砂岩的数字岩石物理模型,采用格子玻尔兹曼方法模拟岩心中油水两相的分布,最后利用蒙特卡洛随机游走的方法模拟数字岩心的二维T2-G及T2-D核磁共振响应,分析了矿物骨架与流体磁化系数差异以及流体饱和对核磁共振响应的影响,对于解释多相流体饱和条件下核磁共振测井信号具有指导意义。     

利用核磁共振测井资料识别天然气

核磁共振测井是新型测井方式,利用核磁共振测井可以可确定束缚水体积、可动流体体积、毛管束缚水饱和度等储层参数,本文主要利用核磁共振测井识别天然气,采用核磁共振测井中的位移谱、T2对数平均曲线和回波比曲线对天然气的识别进行相关分析。     

七区八道湾组油藏测井评价

本文通过岩心刻度测井技术,结合测井和岩心分析资料,利用统计学原理,采用G auss函数通过标准层对所需的测井曲线进行校正;在对储层的四性关系研究的基础上,建立了储层孔隙度、渗透率、泥质含量和含水饱和度测井解释模型。利用此模型对七区八道湾组油藏的储层参数进行解释,解释精度可信,其结果与实际生产情况吻合,适用性较好。     

基于测井资料的储层物性参数模型分析

随着钻井取心和岩心分析技术的不断提高,利用岩心刻度测井建立测井解释模型将更好的提高测井解释精度以及储层精细描述程度。通过分析测井数据标准化、岩心归位等,利用岩心分析的孔隙度(φ)和声波时差曲线(AC)建立储层孔隙度解释模型;通过岩心分析的孔隙度与岩心测量的渗透率建立渗透率数学模型;选用阿尔奇公式建立储集层的含水饱和度解释模型。     

核磁共振测井T_2截止值的确定方法研究

目前,T2截止值的确定问题是核磁共振测井应用的困难之一。T2截止值是决定核磁共振测井资料解释的一个关键参数,对于确定孔隙度、渗透率、饱和度等解释参数十分重要。目前国内外如斯伦贝谢公司推荐T2截止值在砂泥岩和碳酸盐岩地层分别选用33ms和92ms。实际研究发现T2截止值是变化的而非是单一值。直接运用经验值计算地层参数势必会产生误差。因此,根据测量对象的不同,基于岩心实验法,探讨了T2截止值的确定方法,并证明了其可行性。     

薄层电阻率测井的校正方法研究

为了对薄层深感应电阻率进行有效的校正,本文利用岩心实验分析资料并结合测井曲线特征,分别建立了深感应电阻率的岩性和层厚校正模型,以校正岩性以及层厚对薄层测井响应造成的影响,通过校正后的效果对比表明,计算的含水饱和度与岩心分析的饱和度非常接近,表明在研究区本文所用方法对薄层电阻率校正的实际效果很好,具有可行性和实用性。     

低渗储层非均质性对电阻率的影响研究

电阻率参数是测井解释中反演储层流体饱和度的重要资料,低渗储层具有非均质性较强、裂缝较发育等特征,将对电阻率测量产生较大影响.为充分考虑低渗储层非均质特征,准确计算储层含油饱和度,本文通过岩心实验研究了渗透率和裂缝对电阻率值的影响规律.研究发现,相同饱和度下不同渗透率岩心的电阻率值不同,渗透率越高电阻率值越低;法向裂缝的...     

Prediction of Permeability for Chemical Vapor Infiltration

Accurate estimation of the permeability of fibrous media is extremely important for designing and optimizing composites processing. Compared with the liquid processing of composites, the researchers on chemical vapor infiltration (CVI) are more concerned with detailed knowledge of the variation in permeability during the densification. Although, many models and theories have been developed to relating the permeability of porous medium to their structural properties, the ones can be directly applied to CVI are very limited. Thus, in this study, we numerically calculate the permeability of six types of fiber or fiber bundle structures in the high and intermediate density domain (porosity is less than 70%) and the applicabilities of Tomadakis's and Gebart's permeability models to CVI are studied. Our study shows that the original form of Tomadakis's model overpredicts the viscous tortuosity (underpredicts the permeability) in most cases, thus his model should be modified by introducing a new parameter, whereas the general form of Gebart's model with three adjustable parameters is able to predict the evolution of permeability fairly well. Furthermore, our prediction is compared well with the reported data from various references not limited to CVI, thus could also be useful for other engineering applications.     

核磁共振测井渗透率模型及其应用

渗透率是储层评价的重要参数之一,利用测井方法求取渗透率是最经济的。常规测井已经发展了多种计算渗透率的方法,但是这些方法在精度和通用性方面尚不能满足储层评价的需要。核磁共振测井得到的回波串中包含了孔径大小及流体赋存状态等十分丰富的信息,用核磁共振测井来确定地层渗透率有独特的优势。本文综述了目前国内外常用的三种核磁共振测井渗透率模型,Coates模型、SDR模型以及回波串的和计算公式,介绍了这三种模型的基本形式,各自的特点及适用范围。     

The hydrodynamics of trickling flow in packed beds operating at high pressures. The relative permeability concept

One of the largest experimental databases of measured pressure drops and liquid holdups in high-pressure trickle-bed reactors is presented in order to evaluate the currently existing models for the prediction of hydrodynamic parameters of cocurrent two-phase flow through packed beds. Our findings support the conclusions of Carbonell (Oil & Gas Science and Technology—Revue de l'IFP 55 (2000) 417) based on theoretical analysis of existing models that only the relative permeability model and the fluid–fluid interaction model are based on solid hydrodynamic principles, which are able to predict the hydrodynamic parameters within the experimental error. Special emphasis has been given to the relative permeability model to demonstrate its practicalness in describing the complex phenomena existing within the two-phase flow through porous media.     

煤热解模型的研究方向

介绍了各种热解模型,并对最近发展起来的各种网络模型（ＦＧ－ＤＶＣ模型,ＦＬＡＳＨＣＨＡＩＮ模型,ＣＰＤ模型）进行了较全面的比较,认为如果减少模型中的参数,而且各输入参数若能由＾１３Ｃ－ＮＭＲ直接得到,便可使各个模型更加完善。     

Unified determination of relative molecular diffusivity and fluid permeability for partially saturated cement-based materials

From conductivity theory, general models for relative molecular diffusivity and fluid permeability are first derived with unknown tortuosity function and modification coefficient, which can be respectively deduced from hydraulic diffusivity and water retention curve (WRC). Based on empirical laws for hydraulic diffusivity and WRC of cement-based material, unified models for relative molecular diffusivity and fluid permeability are further formulated with only two measurable parameters. Because of practical difficulty for measuring water permeability and pure gaseous molecular diffusivity, only relative gas permeability and relative chloride diffusivity models are verified by the reported data. It is found that the predicted relative gas permeability agrees with measured values and exponential law is a little more preferable than power law for quantifying hydraulic diffusivity. Moreover, relative chloride diffusivity from the unified model also agrees well with experimental data derived via Nernst–Einstein Equation. However, the unified model doesn't capture the possibly overestimated relative chloride diffusivity from Fick's law.     

稠油高温相对渗透率实验数据处理方法及软件开发

稠油高温相对渗透率实验数据处理包括水热物性参数计算、实验数据光滑插值、模型求解,这些过程依靠手工计算繁琐,效率低。常规相对渗透率数据处理方法拟合函数单一,适应性差。为此采用了Borland C＋＋编制了稠油蒸汽驱油、湿氮气驱油和热水驱油三种实验条件下的相对渗透率数据处理计算软件,提供了多种数据拟合和处理方法,并且考虑了实验仪器死体积中原油产出非活塞驱、压力滞后、数据波动、数据异常等因素的影响。该软件可以提高高温相渗数据处理的效率和准确性,易于实现数据处理的规范化。     

Evolution of coal permeability from stress-controlled to displacement-controlled swelling conditions

When a coal sample is constrained either by displacements or by a confining stress, additional force and resulting stress develop within the coal. A simple “free expansion + push back” approach is developed in this work to determine the magnitude of this stress and its effect on permeability evolution. In this approach, the coal is allowed to expand freely due to gas sorption, and then it is pushed back by the applied effective stress to the original constrained conditions. The total “push-back” strains are used to calculate the change in coal permeability. This free expansion plus push back approach is applied to examine the variety of permeability responses observed in the laboratory and the veracity of their representation by theoretical models linking this behavior to gas sorption-induced swelling/shrinkage. These cases include (1) coal swelling tests under the uniaxial strain condition; (2) coal swelling tests under the displacement controlled condition; (3) coal swelling tests under the stress controlled condition. These responses are verified against other coal permeability models available in the literature and against experimental data and field data where few analytical solutions are currently available. In particular, this approach has led to a new coal permeability model that can be used to explain stress-controlled experimental observations. Stress-controlled swelling tests are normally conducted in the laboratory to characterize the evolution of coal permeability under the influence of gas sorption. Typically reductions in permeability are observed from gas-sorption-induced swelling even where effective stresses remain constant. This behavior remains enigmatic as the permeability of the porous coal is determined by the effective stress only. Our model is capable of replicating this apparently anomalous behavior.     

Comparative 27Al NMR and LAXS studies on rapidly quenched aluminosilicate glasses

Aluminium site occupancies deduced from ²⁷Al NMR measurements of several aluminosilicate glasses of composition 35–60 mol% Al₂O₃ were used to calculate the mean coordination number, assuming two polyhedral models. In the models the 30 ppm Al NMR resonance was assigned to fivefold coordinated Al or to distorted tetrahedral units, respectively. Comparison of these mean coordination numbers with those derived from pair distribution functions (PDF) from X-ray scattering data of these glasses support the model in which the 30 ppm Al NMR peak is assigned to distorted tetrahedral units. This conclusion is also supported by simulations of the PDF line profiles using the NMR site occupancies and mean polyhedral bond lengths.     

A fractal in‐plane permeability model for fabrics

In this paper, a fractal in‐plane permeability model for various fabrics is developed. The model is based on the fractal characteristics of pores in fiber preforms. Four different glass fabrics are considered in the modeling: plain woven, 4‐harness, bidirectional stitched, and continuous strand random mats. The fractal in‐plane permeability model can be expressed as a function of the pore area fractal dimension and architectural parameters of the fiber preform. This model also relates the permeability to porosity changes of fiber preforms under compression, which usually occurs in the molding processes. To verify the applicability of the model, the results from the present fractal model are compared with those from the one‐dimensional analysis model and with a set of permeability measurements. Good agreement is found between the two models and the permeability measurements in the general porosity ranges of interest.     

CONVECTIVE DRYING OF PAPER CALCULATED WITH A NEW MODEL OF THE PAPER STRUCTURE

Paper drying models are based on the assumption of a rigid solid matrix. Because of the interaction of water molecules and paper fibre the dimensions of the sheet are changing, especially the thickness. These changes influence the moisture transport within the material. A model of the paper structure has been developed taking into account different kinds of pores in the paper.

By the assistance of this model the dependence between water content and thickness or transport parameters as permeability and thermal conductivity can be predicted. The only informations which are needed are sorption isotherms, apparent paper density and permeability of the single phase flow. Further informations as the pore size distribution are useful but not necessary.

The transport parameters are generated in the suggested way for wood pulp. It is shown that in the case of convective drying, the agreement between experimental results and model simulations is good.