克拉苏构造带盐下超深层储层的构造改造作用与油气勘探新发现

塔里木盆地克拉苏构造带油气群下白垩统巴什基奇克组埋深超过6 000 m,储层基质渗透率低,裂缝普遍发育,构造对储层的改造作用明显,但博孜9井的勘探突破反映出不同区带间构造改造作用差异较大、非均质性极强,重新认识构造对储层的改造作用对于预测超深层储层、指导油气勘探生产具有重要的意义。为此,基于钻井取心、构造平衡恢复、裂缝充填物同位素测年、区块应力数值模拟等资料,结合流体包裹体、声发射古应力、铸体薄片等实验分析方法,从定性分析到定量计算、研究了克拉苏构造带油气群超深层储层的构造改造作用及其差异性。研究结果表明:①北部天山造山带及南部古隆起控制了该构造带储层的沉积格局及差异构造变形,形成巴什基奇克组储层"西薄东厚"的分布特征;②博孜区段古应力最小,构造变形主要为正向挤压、逆冲传播,局部井区为斜向压扭;③大北区段主要为斜向压扭,古应力较小,构造变形为逆冲叠置;克深区段古应力最大,构造变形主要为正向挤压、后缘逆冲抬升、前缘滑脱收缩;④差异构造变形使同一构造带不同构造变形样式的构造减孔量呈现出较大的差别,且控制了不同区段造缝期与成岩胶结的叠加影响、中晚期裂缝网络与油气成藏期的配置关系,加剧了储层的非均质性,是区段间产能差异的基础改造因素;⑤现今构造应力的大小及方向影响裂缝有效性,南部为强挤压应力区,背斜相对高部位裂缝走向与现今应力交角较小,裂缝有效性最好;⑥构造成岩环境决定了构造裂缝充填物的类型,北部区块以淡水—半碱水介质成岩环境为主,裂缝充填物类型为方解石,有利于对储层进行酸化压裂改造。     

Sensitivity analysis of Johnson-Cook material parameters on adiabatic shear in different directions

ABSTRACT

This study investigates the effects of strain, strain rates, and forming directions (RD-rolling direction, TD-transverse direction, and ND-normal direction) on adiabatic shear, via dynamic impact compression tests using the Split Hopkinson Pressure Bar (SHPB) apparatus. A modified Johnson-Cook (J-C) constitutive model is proposed, which used to analyse the influence of the constitutive parameters on the sensitivity of adiabatic shear, employing a finite element software. The different sensitivities of adiabatic shear under different directions are explained by combining microscopic analysis and results from mechanical responses. The results show that the sensitivity of adiabatic shear can be related to the time of stress collapse in the following trend: ND?>?TD?>?RD; the sensitivities of these constitutive parameters on adiabatic shear are calculated and compared.     

回采巷道过断层施工技术

受断层影响,巷道过断层期间掘进速度缓慢,影响采掘接替和矿井生产效率。为了更好地促进矿井生产,以23上04轨顺掘进为研究对象,采用FLAC 3D软件模拟巷道过断层时巷道围岩变形量和塑性区范围,并将围岩划分为正常围岩、过渡带和破碎带3部分。根据模拟结果可知,围岩变形量和塑性区范围都在过渡带开始增大,在破碎带达到最大值。巷道采用后退卧底法过断层,并对断层破碎带及时采用锚网索、注浆、U型钢棚进行支护,通过联合支护相互配合,可以共同提高巷道支护强度,增强巷道顶帮抗变形能力。     

Production of Particle‐Stabilized Nonspherical Emulsion Drops in Simple Shear Flow

Nonspherical drops are of interest in the formation of microcapsules in life sciences like food, pharmacy, and cosmetics, agro and fine chemicals as well as material sciences. Out of many systems, particle‐stabilized emulsion drops, so‐called Pickering emulsions, exhibit an interesting formulation. Systems with Pickering particles applied in an excess amount were investigated. During deformation, the particles fully covered the enlarged drop interfaces and prevented its relaxation to a spherical drop shape. Nonspherical drops could be produced in simple shear flow using an adequate process routine. The production in a simple device is a promising high‐throughput alternative to microfluidic devices.     

Structural fatigue crack growth on a representative volume element under cyclic strain behavior

By introducing parameters λ and ω into the crack tip field, a unified cyclic stress and strain field was first formulated by using the Hutchinson-Rice-Rosengren (HRR) field and the Rice-Kujawski-Ellyin (RKE) field under plane stress states in the present study. On the basis of the plastic strain energy and the linear damage accumulation, two fatigue crack growth models without any artificial parameters were then proposed from a representative volume element of cyclic strain behavior. The fatigue crack growth model included parameters λ and ω which showed the effect of two singularity fields. In addition, a simplified structural fatigue crack growth model was eventually established in terms of the fatigue life of each point on the crack front and the non-self-similar shape evolution law. Finally, the predictions of models are compared with the experimental data and the agreement is found to be fairly good.     

Origin of stress overshoot in amorphous solids

Based on the shear-transformation-zone (STZ) theory, we propose a constitutive model for describing homogeneous elastoplastic deformation of amorphous solids where the interaction of shear transformations and free volume dynamics is incorporated. This theoretical model can reproduce the stress overshoot behavior that shows the dependence of strain rate, temperature, STZ population and dilatancy of systems. It reveals that the stress overshoots its steady state value due to the delayed activation of shear transformations that results from the insufficient free volume in the system. However, the subsequent strain softening (stress drop) is attributed to the shear-induced dilatation that is a result of the positive interplay between shear transformations and free volume creation, the latter playing the dominant role. Our analysis also demonstrates that the STZs, as basic carriers of amorphous plasticity, govern the yielding of the system, whereas the free volume dynamics significantly affects the post-yielding behaviors.     

碳化钒析出对X80管线钢焊接热影响区韧性的影响

通过Gleeble-3500热模拟机对钒(V)含量分别为0.06%和0.02%的X80管线钢进行了峰值温度为1350℃和750℃的焊接热模拟试验,利用硬度计和光学显微镜(OM)分别分析了焊接热模拟试样硬度和试样中马氏体-奥氏体岛状组织(M-A)的数量、尺寸和形貌。利用透射电镜(TEM)对母材、粗晶区和部分相变区中粒子析出进行了表征。结果表明,与0.02%含V量X80管线钢相比,0.06%含V量的X80管线钢由于V含量较高,在受到多道次焊接热循环影响时,部分相变区有较大量碳化钒(VC)粒子析出,明显阻碍位错运动,使其强度明显提高的同时脆性增大、塑性变形难以进行,导致其焊接热影响区韧性下降。     

The analysis and comparison of two novel kinds of focusing elements as reflectors

In this article, two novel kinds of focusing elements as reflectors are analyzed and compared. One is the grooved Fresnel zone plate reflector with continuous phase‐correcting. The other called subzone paraboloid reflector, has the profile that consists of a series of paraboloids. Their diffraction efficiencies and bandwidths are described. The two elements still preserve the advantages of Fresnel zone plates, namely, low profile, high efficiency, and simple fabrication. Two dual‐reflector antennas using the proposed focusing elements as the main reflectors are simulated and the results show that these antennas have good radiation performances. © 2014 Wiley Periodicals, Inc. Int J RF and Microwave CAE 25:101–108, 2015.     

Highly transparent terbium gallium garnet crystal fabricated by the floating zone method for visible–infrared optical isolators

Highly transparent terbium gallium garnet (Tb₃Ga₅O₁₂; TGG) single crystal having a large Verdet constant based on the visible and near-infrared region (VIS–NIR) Faraday rotator was grown by Floating Zone (FZ) growth machine. We successfully grew TGG single-crystal rods of 8–10 mm in diameter, which was suitable for the use in optical devices. The crystal showed a full-width at half-maximum as little as 18 arcsec by the X-ray rocking curve measurement. The Faraday rotation (B = 0.55T) was investigated at wavelength of 532, 632.8, 1064 nm at room temperature. The lower weak absorption coefficient, higher Verdet constant, thermal conductivity and laser induced damage threshold (LIDT) compared to the commercial TGG gives the great potential of using this new method to meet the increasing demand of VIS–NIR Faraday rotators (FRs).     

Macromolecular motions and hydrodynamic radius variation in dilute solutions under shear action

Understanding the dynamics of single polymer chains and rheological mechanism in dilute polymer solutions under shear stress is essential for fields such as the petroleum and food industries, biomedical materials and drug delivery. Here we present an experimental method for measuring the viscosity of polymer solutions and studying the variation of single polymer chain conformation and the mechanism of molecular motions according to the relationship between the intrinsic viscosity, [η], and the shear rate. Of striking interest is that we find that [η] changing with the shear rate presents three stages which may explain the nature of the viscoelastic performance of polymer solutions and the isolated molecular motions. The significance of these results is the finding of the polymer chain deformation to match the pore throat which has enormous potential implications in drug delivery, genetics and biomedicine © 2014 Society of Chemical Industry.