考虑变形影响的致密砂岩油藏非线性渗流特征

致密砂岩油藏水驱渗流特征体现非线性渗流规律,存在启动压力梯度,且水驱过程中多孔介质会产生变形,岩石渗透率降低。通过电镜扫描试验研究致密砂岩纳米级微观孔隙特征,结合岩石颗粒分布特征,建立致密砂岩变形引起应力敏感理论模型,得到岩石介质变形系数,并与试验测试结果进行对比分析;建立考虑致密砂岩岩石变形影响的渗流数学模型,研究启动压力梯度及介质变形共同作用对油、水两相非线性渗流特征影响。算例结果表明,启动压力梯度与介质变形的耦合作用造成水驱渗流阻力增大,地层压降损失增大;介质变形系数越大,相同生产时间内原油采出程度越低,随着生产时间增加,地层压降损失幅度增大。     

Direct Observation of Internal Structure in Spray-Dried Alumina Granules

The internal structure of spray-dried alumina granules was characterized by optical microscopy by immersing them in a liquid having a refractive index close to that of alumina. This method provides a unique technique for the detailed analysis of the internal structure of spray-dried granules.     

A NUMERICAL SOLUTION FOR THE ANOMALOUS SEDIMENTATION OF A SMALL BROWNIAN SPHERE IN A VERTICAL CYLINDER OF PERIODICALLY VARYING RADIUS

We consider the long-time asymptotic transport of a small Brownian sphere that is sedimenting through a viscous fluid within an infinite vertical cylinder whose radius changes periodically and abruptly between two values. Use of generalized Taylor dispersion theory gives rise to a set of steady-state differential equations that govern the long-time mean velocity. We prove that these equations possess a unique solution. Finite difference discretization of all governing equations and boundary conditions, except for the normalization condition, leads to a homogeneous system of equations that possesses an infinite number of solutions. Application of the normalization condition selects the particular solution of the set that satisfies all conditions. Despite the absence of classical wall effects, the long-time mean velocity of the particle through the pore is generally less than the Stokes sedimentation velocity that applies at every point within the fluid. This anomalous behavior could be used to enhance force-driven separation of Brownian particles that possess identical Stokes velocities but different diffusivities. Furthermore, this numerical approach may be applied to similar problems.     

气—液传质设备浮阀复合塔板的应用

介绍气～液传质设备中浮阀复合塔板的应用情况，采用浮阀复合塔板可在尽可能不降低板效率的同时提高塔器的生产能力。     

Settlement of composite foundation with discrete material pile considering modulus change

Based on deeply discussing the deformation mechanism of composite foundation with discrete material pile, firstly, the settlement of composite foundation in rigid foundation conditions was assumed to consist of two parts, an expanding part and an un-expanding part. Then, in view of the differences of deformation properties between the expanding part and the un-expanding part, the relationships between the pile modulus and the applied load in these two parts were respectively developed. Thirdly, by introduci...     

孔隙介质三维逾渗机制数值模拟研究

 论述三维孔隙介质的逾渗研究方法，基于VC++6.0开发三维逾渗模拟软件。利用重正化群原理，通过数值模拟的方法研究孔隙介质三维逾渗机制和逾渗团特性，提出有效表面积率概念。研究结果表明：团的数量随着孔隙率的增加先增加后减小，在孔隙率为0.20时达到最大值；随着孔隙率的增加，最大团表面积在孔隙率大于阈值时开始快速增加，然后呈减小趋势，在孔隙率为0.55时达到最大值，此时的有效表面积率达到0.98；当孔隙率为逾越阈值0.311 6时，发现逾渗团的大小是一种统计上的随机分形，其分形维数D = 2.934。     

采用多点地质统计法重构页岩的数字岩心

由于实验设备获得的页岩岩样大多是微米或毫米尺度,如果要获得更大尺度和范围内的孔隙结构,必须通过对其特征的三维重构才能实现。为此,提出了基于纳米精度的体数据与多点地质统计方法的页岩三维数字岩心重构方法。以页岩纳米CT数据为训练图像,使用数据模板提取其中的结构特征,通过多点地质统计方法将结构特征重构到数字岩心中;形成了以变差函数曲线、孔隙直径分布和孔隙连通性来判别重构岩心与真实页岩结构相似度的判别方法 ;基于格子玻尔兹曼方法验证了相似度评价方法。结果表明:(1)变差函数可以检验重构岩心与真实岩心的空间相似性,孔隙直径分布和孔隙连通性可以检验流动特征的相似性;(2)当变差函数曲线、孔隙直径分布和孔隙连通性相似时,重构岩心与真实岩心的渗透率相近,表明所提出的重构方法与结构相似度评价方法是有效的;(3)由于强非均质性,不同位置的重构页岩岩心渗透率差异可超过100倍。该研究成果对构建三维大尺寸强非均质性页岩数字岩心、认识页岩孔隙结构、分析流动规律具有指导作用。     

低温氮吸附法与煤中微孔隙特征的研究

对不同矿区24个煤样作了低温氮吸附试验,分析了吸附等温线及吸附回线的形态、类型,划分出L1,L2,L3型3种煤的低温氮吸附回线类型,讨论了共与煤中微孔隙发育特征的关系。试验结果表明,煤中孔隙是从小至分子级（孔径约0．86nm）大至无上限的较连续的孔系统,其中孔形结构可分为：开放型透气性Ⅰ类孔;一端封闭的不透气性Ⅱ类孔;细颈瓶形Ⅲ类孔,煤中孔径约小于3nm的孔大多为一端封闭的Ⅱ类孔;细颈瓶形孔的瓶劲直径也是3nm左右。     

变温条件下煤结构与吸氧量的关系

采用压汞法技术定量测定了在不同温度与压力下煤样的孔径、孔容积与煤的表面积的值；用分形理论对煤在定压变温条件下结构参数进行分形特征描述，并对用孔径与孔容两种分形维度的值表示煤的孔隙结构的合理性进行了比较.当煤温<100 ℃时，煤的容积分形维数增大，吸氧量增加，孔隙容积对煤的吸氧量起主要作用；当煤温≥100 ℃时，煤的分形维数减小，煤的吸氧量也增加，这是由于煤的吸氧量主要是氧化反应速率决定的，孔隙结构特征对煤的吸氧量影响很小.