Measurement and Modelling of Gas Condensate Flow Around Rock Perforation

In the petroleum production industry wells are mostly cased and perforated in the producing formation. Perforation characteristics such as size, length, number of perforation tunnels and their arrangements as well as fluid and rock properties determine fluid flow behaviour in the wellbore region, hence, well productivity. Flow of gas and condensate around a perforation tunnel (including the damaged zone) has been studied by performing steady-state core experiments and simulating the results numerically, using a finite element modelling approach. The model allows for the changes in fluid properties and accounts for the coupling of the two phases and the inertial effect using a fractional flow based correlation. The results indicated that different sets of thickness-permeability (h−k) values obtained from matching single-phase flow performance could be assigned to the damaged zone around perforation to represent the two-phase flow performance. The status of the tip of the perforation for two extreme cases of totally closed and fully open was investigated and found to have a minimal effect on the performance of the system.     

The temperature‐dependent ballistic performance and the ductile‐to‐brittle transition in polymer networks

The temperature dependence of the ballistic impact performance of a series of transparent polymer networks is evaluated. A systematic series of homogeneous epoxy/propylene‐oxide‐based thermosets, a nanoscale phase‐separated epoxy/dual amine thermoset, and two homogeneous, completely aliphatic materials synthesized via ring‐opening metathesis polymerization are examined. The Vogel temperature (T_o) and the Kauzmann temperature (T_K) are critical parameters for scaling the temperature‐dependent ballistic impact performance of each class of materials. The ductile‐to‐brittle transition temperature in a series of propylene‐oxide amine‐cured epoxies occurs at the material T_K, corresponding to a sharp drop in fracture toughness and ballistic impact performance. Two aliphatic, ring‐opening metathesis polymerized materials are found to exhibit no clear transition from purely ductile to purely brittle behavior, but the temperature dependence is still scaled to a single curve when normalized by T_o. The cooperatively rearranging region (CRR) or the volume of this region is related to the breadth of temperatures over which these materials exhibit purely ductile deformation both quasi‐statically and at higher rates. The temperature‐dependent performance is discussed in the context of the configurational entropy. The breadth of the ductility window is related to the size of the CRR, calculated from calorimetric measurements at the resin T_g. Published 2019. This article is a U.S. Government work and is in the public domainin the USA. J. Polym. Sci., Part B: Polym. Phys. 2019 , 57, 511–523     

Hopkinson压杆技术在中国的发展回顾

简要回顾了Hopkinson压杆实验技术在中国的发展历程及推广应用。系统介绍了关于金属、高聚物、复合材料、脆性材料、混凝土及软材料、泡沫材料等材料的SHPB实验技术研究，并对相关材料的实验结果进行简要讨论。     

离子选择性电极测定岩石矿物中的氯

用离子选择性电极法测岩石中的Ｃｌ＾－，相对误差不大于５．０％，处理成溶液后的检出限为１．５＊１０＾－６ｇ／ｍＬ。     

Raman spectroscopy as suitable tool for the field study of recent volcanic environments

In 2013, a portable Raman setup was implemented for on‐site and rear‐base characterization of volcanic products. Silica and rutile rock coatings, sulfate incrustations and speleothems, plagioclase, clinopyroxene, and (Fe, Ti, Cr) oxides lava minerals were identified on the young lava flows of Piton de la Fournaise volcano. These analytical abilities opens the way of in situ study of the first aging and weathering steps of recent lava flows. This paper relates the preliminary results of the field campaign. Three months after the investigation, all the speleothems have naturally disappeared. Copyright © 2016 John Wiley & Sons, Ltd.     

ANALYSIS OF MECHANICAL PROPERTIES OF CEMENT CLINKER UNDER DIFFERENT TEMPERATURES BASED ON HERTZIAN INDENTATION METHOD1)

本文通过高温球压法得到各种脆性和准脆性材料的表面压痕应力与应变之间的关系曲线。通过压痕应力-应变曲线的分析既可比较方便地确定出材料的压痕弹性模量、剪切模量和布氏硬度,又可比较不同温度下水泥熟料的变形性能。在不同温度(25 ${^\circ}\!$C$\sim $1400 ${^\circ}\!$C)处理下,球压应力松弛试验载荷松弛,在载荷峰值为100 N时,随着温度的升高,水泥熟料载荷松弛更明显。随着温度从500 ${^\circ}\!$C升高到1400 ${^\circ}\!$C,载荷松弛非常明显,尤其温度高于1200 ${^\circ}\!$C,水泥熟料样品内部的硅酸三钙(Ca$_3$SiO$_5$, 简称C3S)分解以及有部分液相的出现引起的应力松弛现象最为明显,在1275 ${^\circ}\!$C时熟料基本上已经软化,载荷急速松弛,所以认为1275 ${^\circ}\!$C为熟料的脆延转化温度。通过水泥熟料高温球压松弛试验可以确定水泥熟料在二次加热过程中的脆-延转化温度,测定熟料弹性模量和抗压强度急剧变化的温度范围。研究水泥熟料在不同温度下的力学行为和力学特性,探索提高粉磨效率的新途径,实现高温下的低能耗粉碎。     

Nonlinear Coupled Mathematical Model for Solid Deformation and Gas Seepage in Fractured Media

Based on detailed investigation into the interactional physical mechanism of solid deformations and gas seepage in rock matrix and fracture, a nonlinear coupled mathematical model of solid deformation and gas seepage is put forward and the FEM model is built up to carry out numerical analysis. The coupled interaction laws between solid deformations and gas seepage in rock matrix and fractures has been emphasized in the model, which is a vital progress for coupled mathematical model of solid deformation and gas seepage of rock mass media. As an example, the methane extraction in fractured coal seam has been numerically simulated. By analyzing the simulation results, the law of methane migration and exchange in rock matrix and fractures is interpreted.     

Dynamic force-penetration curves in rock by matching theoretical to experimental wave propagation response

A methodology to obtain the dynamic force-penetration curve of a rock specimen is presented. For this, a simple portable experimental setup is used. On one end, a hand-held hammer strikes a slender chisel. On the other end the chisel is in contact with the rock specimen into which the generated stress wave propagates. Strain gages installed at a selected section of the chisel are recorded throughout the impact duration. The theoretical signal at the same section is simulated using a numerical method based on the impulsemomentum principle previously developed by the author. Essentially the shape of the simulated theoretical response at the strain gage section depends on the impact velocity of the hammer and the slope of the assumed force-penetration curve. These two parameters are adjusted until the shape of the theoretical signal at the strain gage closely matches the experimental signal. Due to its simplicity, the proposed methodology has the potential of becoming a standard dynamic test for obtaining the force-penetration curvs in rocks.     

分段爆破地震强度的试验研究

在爆破实验中,通过调整段数、分段炸药量、炸药总量、间隔时间、孔网参数、岩石波阻等爆破相关因素,以改变各分段爆破地震波持续时间、段别间爆破地震波重叠程度来研究爆破地震强度与爆破相关因素间的相互关系。阐明了爆破地震波传播规律及其破坏行为特征,以及各个爆破相关因素对爆破地震强度的影响程度。获得了确定段数等爆破参数的规则,从而为生产实践设计最佳爆破参数提供理论依据。     

基于曲梁弹性理论的弯曲覆岩变形及应力分析

引入适用于极坐标下曲梁的位移函数,通过理论分析得出用位移函数表示的曲梁控制方程和位移分量、应力分量.在此基础上,采用差分原理给出曲梁控制方程、位移分量和应力分量的差分代数方程.最后,采用数值计算方法,分析了煤层开采后弯曲覆岩的位移和应力分布特征,结果表明:1)煤层开采后弯曲覆岩产生下沉变形;弯曲岩层环向位移既有拉伸也有压缩.2)离开切眼不远处径向应力将达到峰值,径向应力由内边界向外逐渐增大;工作面后方不远处环向应力将达到峰值,环向应力较容易引起压缩破断;离开切眼不远处剪应力将达到峰值,对于小角度截面上的剪应力由内边界向外逐渐增大.研究结果为煤矿工程提供了科学依据与参考.