Three dimensional couette flow and heat transfer through a porous medium with variable permeability

This paper reports research on the effects of variations in injection velocity and permeability on the heat transfer and flow through a highly porous medium between two horizontal parallel plates situated at constant distance with constant suction by the upper plate. Due to this type of variation in injection velocity and in permeability the flow becomes three dimensional. The governing equations are solved by adopting complex variable notations to obtain the expressions for the velocity and temperature field. The skin-friction along the main flow direction and rate of heat transfer are discussed with the help of graphs.     

土-岩系统对洞穴景观风化的影响 --以云南弥勒白龙洞为例

云南弥勒县白龙洞发育于三叠纪灰质白云岩中,洞中碳酸钙景观的风化现象比较明显.本文从洞穴风的影响和碳酸钙沉淀条件两方面分析风化的原因,结果表明:土-岩系统的特点在其中起着十分重要的作用:①它可以通过控制洞腔形态影响洞穴风速变化;②水中CO2排放通量受滴速影响成为新洞积石形成的决定条件之一;③利用HYDROWIN程序,证明了洞穴滴水的主要矿物成分对景观物质组成的影响.     

Effect of soil-rock system on speleothems weathering in Bailong Cave, Yunnan Province, China

Bailong (White Dragon) Cave locates in theBailong hill occupied by Middle Triassic calcareousdolomite in Mile County, 200 km south to Kunming,Yunnan Province, China. The cave entrance is lo-cated in N 24°11′55.2″, E 103°20′59.7″, 1500 mabove sea level. The tourist trail in the two-level caveis 1118.8 m long: the upper level is 477 m long andthe lower level 641.8 m long. The cave is in sub-tropical semi-humid and plateau climate zone withannual average temperature of 17.3 °C and av…     

S和S-L型构造岩的显微组构与渗透性能的声学识别

为了解断裂与流体渗透的动态关系,针对S和S-L型构造岩及其原岩,采用超声波实验方法测算岩石的波速和衰减,经过与孔隙度等微孔隙结构参数的对比和相关分析,研究认为：S-构造岩和（S-L）-构造岩具有明显的各向异性,在平行面理方向上,波速和品质因子较大,渗透性最强,是最佳的流体运移方向;在垂直面理方向上,波速和品质因子较小且通常小于原岩的,封闭性最强,是最佳的封闭流体方向.波速和品质因子分别与孔隙度具有负线性关系,与气柱高度、突破压力等表征岩石封闭性能的参数具有正相关关系.张性角砾岩的波速和品质因子小于原岩的,而渗透性增强,并无明显的各向异性.     

Nonlinear analysis of consolidation with variable compressibility and permeability

INTRODUCTION Since the development of the conventionalconsolidation theory by Terzaghi (1943) in 1923,many attempts have been made to present some solu-tions for the problems considering more realistic as-sumptions on the practical geotechnical engineering.Some efforts have been made to avoid limitation ofthe assumptions in the Terzaghi’s theory. During theconsolidation of soil, it is obvious that the coefficientof volume compressibility mv and the coefficient ofpermeability kv ar…     

Three dimensional Couette flow and heat transfer through a porousmedium with variable permeability

ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｆｌｏｗｏｆａｖｉｓｃｏｕｓｌｉｑｕｉｄｏｖｅｒａｎｄｔｈｒｏｕｇｈａｐｏｒｏｕｓｍｅｄｉｕｍｈａｓｂｅｅｎｔｈｅｓｕｂｊｅｃｔｏｆｉｎｔｅｎｓ ｉｖｅｓｔｕｄｉｅｓｉｎｒｅｃｅｎｔｙｅａｒｓｂｅｃａｕｓｅｏｆｉｔｓｎａｔｕｒ     

Investigation of a novel perforation technique in petroleum wells—perforation by drilling

The objective of perforating the petroleum wells is to maximize well productivity. A good connectivity between the wellbore and formation can lead up to achieve that goal. However, the conventional method of perforation, which basically involves the use of explosive charges, rarely meets the expected well productivity. It is mainly because of the formation of a region of reduced permeability around the perforation tunnel. To offset such and several other shortcomings of present practices, a new technique is required, the highlight of this paper. Described as the ‘perforation by drilling’ (PD), this new technique is examined and compared for its performance with that of another technique, ‘Perforation by Shooting’ (PS). For this, the experimental and numerical results of the PS technique on cylindrical sand samples of varying amounts of strength and porosity are studied. Moreover, in order to achieve a so-called ‘perfect perforation’, results are compared with the ‘Casting technique’. Three different samples were selected for the measurement of fluid flow rate and differential pressure across the perforation using a ‘geotechnical digital system’ (GDS), which is a triaxial testing device. Profiles such as fluid flow rate with a change in differential pressure and pressure build-up data with time, signify that the PD technique can achieve maximum wellbore productivity when compared to the PS technique. Results also indicate that at a 100 kPa differential pressure, the PS, PD and Casting techniques can achieve 0.20, 0.65 and 1.00 mL/s fluid flow rates respectively across a sample. The paper also implements a 1-D time dependent porous media flow model to simulate flow across the perforated cylindrical samples created by the PS, PD and Casting techniques. Results show a good consistency between the experimental and numerical approaches.     

仅与传导电流有关的条件及内涵

本文根据矢量场唯一性定理,对比分析了磁场强度矢量H仅与传导电流Jf有关的充要条件及内涵,进而阐述了在该条件下磁化场的特点及典型应用。     

储层井间注采对应关系分析

油田开发过程中注采井间的注采对应关系一直是开发过程中的重难点,它的好坏直接关系到油田生产过程中的的产量和含水率,而要对注采关系作出合理的调整就必须弄清楚注采井网之间的注采对应关系,这样才能合理的作出调剖、堵孔、补孔等措施,从而提高产量,降低含水率。由于成本和施工条的的限制,很多油田没有动态测井资料或者资料不全,这使得对油田井间注采对应关系的研究更加困难。本文通过油田基本都具备的常规测井资料和生产资料,利用沉积相分析、生产资料分析并结合油藏数值模拟来研究注采井间的对应关系。实践证明这种综合性的方法很好的确立了油田的动态生产关系,为油田生产方案的调整提供了科学依据。     

浅析思想政治教育的渗透性

随着高校扩招、社会发展和社会变化等新情况 ,高校学生思想政治工作出现了许多新问题 ,渗透性教育作为教育方式的基本方式之一在新环境下对于做好学生的思想政治工作具有影响深远、学生乐意接受等特殊功效。本文力求从渗透性教育的内涵与外延、特性、基本原则、方法四个方面做一次初步探索