Modelling the pressure dependence and the influence of added polymeric fibers on the permeability of refractory concretes

In order to facilitate the water evacuation during drying, polymeric fibers are added to refractory concretes. A permeability model using Bruggeman's approach is developed to predict the permeability increase due to the fibers addition. This model (without adjustable parameters) knowing the fibers geometry (given by the manufacturer) and added amount (mass fraction varying between 0 and 0.20%) is validated by a thorough comparison with experimental results. The refractory permeability is measured at ambient temperature varying the quantity of added organic fibers after the samples were fired at different temperatures (from 80 °C to 500 °C). The analysis of results is especially careful to take into account the influence on the permeability, on both pressure (Klinkenberg effect) and firing temperature. The agreement between theoretical and experimental results is shown to be very satisfactory.     

Formation of water-impermeable crust on sand surface using biocement

This paper examines the feasibility of using calcium-based biocement to form an impermeable crust on top of a sand layer. The biocement used was a mixture of calcium salt, urea, and bacterial suspension, which hydrolyzed urea with production of carbonate and an increase of the pH level. Applying 0.6 g of Ca per cm² of sand surface, the permeability of the biocemented sand can be reduced from 10⁻⁴ m/s to 1.6·10⁻⁷ m/s (or 14 mm/day) due to formation of the crust on sand surface. The rupture modulus (maximum bending stress) of the crust was 35.9 MPa, which is comparable with that of limestone. The formation of a water-impermeable and high strength crust layer on sand surface could be useful for the construction of aquaculture ponds in sand, stabilization of the sand dunes, dust fixation in the desert areas, and sealing of the channels and reservoirs in sandy soil.     

Sealing performance of compacted block joints backfilled with bentonite paste or a particle-powder mixture

Technology gaps are inevitable parts of the buffer barriers in the high-level radioactive waste (HLW) repositories. The mechanical properties, permeability and water-solute-radionuclide migration of buffer barrier are different when considering the gaps. The present study was designed to investigate the sealing effect of joint between the compacted blocks with two types of sealing materials, a bentonite paste (P) and a bentonite particles and powder mixture (P/P) both from the macro- and micro-aspects.A series of laboratory test was conducted to study the hydro-mechanical properties of bentonite blocks after backfilling the joint between blocks. Both the intake and outflow water volume, and the pressure on radial and axial direction were monitored during the hydration. Following the permeability test, the joint’s sealing was evaluated by a final dry density, water content distribution and microstructure evolution. The results showed that the axial and radial pressure of blocks backfilled with bentonite P and bentonite P/P mixture were higher than that of blocks with a blank joint. Pressure preferentially increased in the low-stress areas (the joint areas), contributing to sealing of the joint. The hydraulic conductivities for backfilled bentonite blocks were almost on the same order of magnitude as to intact bentonite blocks, revealing a clear sealed hydraulic behavior. The final dry density decreased in the block area and increased in the joint area after hydration, forming a transition zone with a certain width. A smaller difference was found between the block and joint area in the backfilled block. The mercury intrusion porosimetry (MIP) test and scanning electron microscope (SEM) test showed that backfill decreased the numbers of inter-aggregates pores ranged between 8 and 15 μm compared with that in the blank joint. The comprehensive data showed that a joint backfilled with a bentonite P/P mixture has a higher swelling capacity, lower permeability, and denser structure compared with joint backfilled with bentonite P. The results suggested that joint backfilling improved the integrity of the blocks and enhanced the swelling property and impermeability compared with that of the non-backfilled blocks. Both bentonite P and bentonite P/P has satisfactory sealing performance of compacted block joints, with better effect of the later.     

Reservoir characterization utilizing core and wire line logging data for Kareem sandstone,Ashrafi oil Field,Gulf of Suez,Egypt

This study aims to integrate core and wire line logging data for evaluation of Kareem sandstone (Middle Miocene) in Ashrafi Field, Gulf of Suez, Egypt. The study has been carried out on seven wells ASHRAFI_A_01_ST, ASHRAFI_A_02_ST, ASHRAFI_H_IX_ST2, ASHRAFI_I_1X_ST, ASHRAFI_K_1X, ASHRAFI_SW_04, ASHRAFI_SW_06, by using wire line logging data and core data. The interpretation of these data has been done by using Interactive Petrophysics software.The Net pay thickness ranges between 17?ft to about 110?ft, porosity varies from 13% to 26%, permeability from 125?mD to about 960?mD, water saturation from 19% to about 50% and shale content from about 18% to about 56%. The interpretation of the Kareem sandstone (core data for ASHRAFI_SW_04 well) indicates that the average core porosity value is about 17% and the average core permeability is about 800?mD, which indicate a suitable reservoir. The porosity increases with the increasing of the permeability and the relationship between them has good correlation coefficient of 0.81 for wire line logging data set and 0.85 for core data set. These relations can be used to determine permeability from porosity for sandstone of Kareem Formation.The new development area for Ashrafi Field can be determined where there are two zones: one in the Middle and the other in South west. Stratigraphic correlation chart shows that, the Kareem Formation thickness varies laterally in Ashrafi field so, the new well location could be determined perfectly. The integration between well logging data and core data are very important tools to evaluate the degree of heterogeneity in the Kareem sandstone and storage capacity properties as well as the zone of interest of productivity and perforation.     

A semi-empirical model for estimating permeability and inertial coefficient of pin-fin heat sinks

This work presents a novel semi-empirical model for estimating the permeability and inertial coefficient of pin-fin heat sinks that are set as porous media. The forms of correlations for the permeability and inertial coefficient of pin-fin heat sinks are firstly derived theoretically, then a series of pressure drop tests are performed for modifying those correlations. The variable parameters of pin-fins studied herein are the relative longitudinal pitch, the relative transverse pitch, the relative fin height and the relative fin length. The present correlations are reasonable by comparing with the data of other tests. Additionally, within the range of Reynolds number (Re_d = 676-11,252), at a given Re_d, the effect of the relative fin height on the pressure drop is negligible. The pressure drop declines as the relative fin length increases, especially as the relative transverse pitch and the relative longitudinal pitch increase. It increases as the relative transverse pitch declines or the relative longitudinal pitch increases.     

考虑储集层塑性变形的最小射孔深度计算

储集层被打开后,由于原地应力平衡被破坏,井孔周围的应力将重新分布。如果储集层胶结强度较低,近井带存在较大范围的塑性区。由于存在塑性区,以及钻井过程中发生钻井液的滤液及固相颗粒侵入,此双重作用导致近井带的渗透率很低,分成具有不同渗透率的３个带（含塑性作用的损害带,塑性带,弹性带）。由于塑性带宽度较大,其渗透率比弹性带小得多,因此在确定射孔深度时应将塑性带考虑在内。进行了近井周围储集层的弹塑性分析,给出了塑性带半径的计算方法,分析了影响塑性带范围的因素,在此基础上指出：射孔的最小深度应包括塑性带宽度。图３参７（段玉廷摘）     

Influence of pH on the Permeability of p-Toluidine and Aminopyrine Through Shed Snake Skin as a Model Membrane

The influence of pH on the permeability of p-toluidine (pKa, 5.3) and aminopyrine (pKa, 5.0) through shed snake skin as a model membrane was studied. The pH was adjusted to several values, and the solubility of the drugs in each donor was measured. Flux rates and permeability coefficients were calculated from the steady-state penetration portions. The flux rates of p-toluidine decreased as the pH value in the donor solution increased. On the other hand, the flux rates of aminopyrine were constant at any pH value. The permeability coefficients of each drug increased as the pH value in the donor solution increased. The partition coefficients (octanol/buffer) of each drug were dependent on the molecular fraction of un-ionized species. From these results, it is suggested that ionized species of p-toluidine transports through shed snake skin, but the ionized species of aminopyrine does not.     

A Simplified Model for Pavement Drainage

In this paper, we present a simplified model for pavement drainage system. The model accounts for the accumulation and flow of water through a drainable base and edge drain representing a porous medium. There is an inflow through a portion of the boundary (pavement surface) as well as an outflow through a separate part of the boundary (outlet pipe). The model consists of an initial value problem governing the growth of the region saturated with water and an elliptic boundary value problem describing the flow of water within that region. The model is validated using rainfall and outflow data obtained from an instrumented site. The proposed model can be used to evaluate the characteristics of a pavement drainage system as well as to estimate its permeability.     

岩屑P-K物性分析技术研究及应用

该文介绍了岩屑P-K物性分析技术的原理及样品预处理流程,详细探讨了样品预处理过程中,含油样品及不含油样品分别用氯仿和氯化钠溶液浸泡的时间,并根据常规物性资料从成岩演化、粒度和胶结程度三方面,找出P-K分析方法的影响因素。应用该技术在GS48井建立了回归方程,取得了较好的效果。证实了岩屑P-K物性分析技术具有快速、经济、连续等优点。     

钻井液完井液损害油层室内模拟评价程序

保护油气层的室内评价工作主要是借助于有关仪器,测定入井流体对油气层损害后的渗透率变化情况。本文利用JHDS高温高压动失水仪,在确定的实验参数条件下规定了评价各种入井流体对油气层损害程度的模拟评价程序。根据这种程序对江汉油田江陵凹陷沙27井和塔里木塔中TZ-44井岩心进行了模拟评价,通过计算机软件进行数据处理,得出了评价结果,这种评价结果对于现场完井作业具有一定的指导意义。