用于预防和解除有机垢的修井液添加剂

原油沥青质沉积形成的有机垢是造成油气层损害的主要原因之一,并且某些损害是永久性和不可逆的,因此有必要对原油中沥青质的沉积采取有效的预防和解除措施.使用所建立的评价方法,筛选出了能有效预防有机垢损害的修井液添加剂正电聚醇,以及用于解除有机垢损害的修井液添加剂L-01.正电聚醇分子链上的多个羟基具有较强的正电性和比沥青质更强的吸附能力,因此能够优先吸附在岩石表面上,形成保护层,从而起到很好的预防沥青质沉积的作用.L-01中的甲苯对沥青质具有很好的溶解能力,并且其中的石油磺酸(或盐酸)还对无机垢具有一定的溶解和解堵能力.在适宜的加量下,正电聚醇的抑制率可达到100%,而L-01的相对溶解度可达到80%以上.     

罗家寨构造水平井钻井液技术

针对罗家寨构造地质特点及水平井钻井液技术难点,确立了浅井段为深井段做准备、直井段为斜井段做准备、重点解决大斜度井段钻井液技术难题的基本原则.在直井段使用钾钙基聚合醇有机硅聚合物钻井液,引入抑制和防塌能力强的聚合物和有机硅等处理剂,防止直井段的井眼坍塌和钻屑分散;大斜度井段使用钾钙基聚合醇正电胶钻井液,防止形成岩屑床,通过护胶剂、润滑剂、表面活性剂、柴油的复配使用,提高了该钻井液的抗膏盐、酸性气体污染的能力和润滑防卡性能;水平井段使用改性钾钙基聚合醇正电胶钻井液,利用聚合物保护产层,保持过量的除硫剂,以提高钻井液的抗H2S污染能力.现场应用表明,该套钻井液体系能减轻岩屑床的形成、有效地防止了岩屑分散、井漏,降低了起下钻摩阻,有效地保护了油气层,确保了该构造水平井的顺利钻探.     

国外无侵害钻井液技术

介绍了国外无侵害钻井液体系的技术背景,论述了防止钻井液侵入储层技术的发展和无侵害钻井液技术的形成过程,分析了无侵害钻井液的技术关键和封堵机理,并简要介绍了无侵害钻井液组成.该钻井液体系的主要处理剂--无侵害钻井液降滤失剂FLC2000由一系列可溶于油和水的改性聚合物混合而成,这些聚合物具有较宽的HLB值,当加入到水基钻井液中时,混合物中一些聚合物溶解,类似于常规降滤失剂,可以控制滤失量;而另外一些组分由于其亲油特性,只能部分溶解,这些聚合物组成可变形的胶束,在孔喉和微裂缝中快速形成低渗阻挡层,有效地阻止液体侵入.基于上述钻井液组分的作用机理,无侵害钻井液在防止地层伤害、防止衰竭地层的压差卡钻、防止钻井液漏失、提高地层承压能力、控制微裂缝地层的不稳定性等方面具有独特优点.最后总结了国外保护储层钻井液的发展方向.     

旧混凝土防渗渠道破坏的原因及修补改建措施

混凝土是我国渠道防渗工程主要采用的工程材料之一。但我国旧的混凝土防渗渠道经过输水运行后 ,存在着破坏现象 ,有的甚为严重 ,影响了工程的安全运行、效益发挥和防渗效果。为了合理修补改建此类工程 ,笔者根据自己的体会并参考有关资料 ,对旧混凝土防渗渠道破坏的原因及修补改建措施 ,提出初步意见 ,供讨论、交流和参考。     

Analysis of damaged material containing periodically distributed elliptical microcracks by using the homogenization method based on the superposition method

The presence of multiple microcracks in a structural component causes material degradation such as reduction in the stiffness or reduction in the fracture toughness of the component. In this paper, the homogenization method is used to evaluate mechanical properties of the damaged material. The adaptation of the superposition method to the homogenization method is also presented. The proposed method makes use of the finite element solution of uncracked solid and the analytical solution. The effective elastic moduli of damaged materials containing lattice-distribution microcracks are estimated by the proposed method. Furthermore, the stress fields and the stress intensity factors of the elliptical microcracks in the damaged material at a micro-mechanics scale are evaluated to illustrate microscopic behavior such as crack interaction.     

土坝护坡冻害的研究

土坝护坡因冻害破坏数量多、损失巨大 ,文中根据黑龙江省绥分地区大中型水库多年冰压力和坝体冻胀的观测资料 ,分析了水库的冰情规律 ,对土坝护坡冻害原因进行了深入研究 ,得出土坝护坡冻害的主要因素并非是静冰压力 ,而是坝体冻胀破坏 ,并提出了土坝护坡防冻害的措施。     

Si(Au)探测器的快中子辐射损伤

在核实验中,半导体硅探测器常用来对带电粒子和中子进行探测。其能量响应和时间响应特性均十分良好,但是耐辐射性能却较差,尤其在伴有γ和中子本底的环境中,由于辐照引起探测器晶格损伤,导致半导体探测器性能退化,如探测器漏电流增大、能量分辨本领变差、能量亏损增加、时间响应增长等,严重影响探测器的使用和寿命。     

Damage Constitutive Equations and its Application to Fiber Reinforced Composites under Transverse Impact

Two continuous field variables, called as continuity tensor and damage variable tensor, are used to describe the anisotropic responses of an elastic-brittle material under transverse impact load. Based on the continuum damage mechanics, anisotropic damage constitutive equations in both full and incremental forms are proposed here. The expressions of effective elastic module tensor, damage variable tensor and damage propagation force tensor are further derived, and the methods for determining the tensors are explained in detail. An example of strain and damage response of a fiber reinforced composite laminated plate under transverse impact load is employed to demonstrate the application of this theory. In the example, the damage variable coupled with geometric large deformation of laminated plate is also considered. The calculating results illustrate the influence of damage on strain field in the impacted laminated plate.     

甜樱桃嫁接苗与组培苗抗寒性比较

通过对甜樱桃的嫁接苗(早红宝石／大窝娄叶)和组培苗(早红宝石)的枝条以及根系电导率的测定，计算伤害率，并结合生长法，评价两种苗木抗寒力水平。试验证明：嫁接苗和组培苗枝条-22℃左右达到半致死温度。嫁接苗和组培苗根系-9℃左右达到半致死温度。初步可以认为，组培苗与嫁接苗有相近的抗寒力水平、经过深入试验实践，组培繁苗可以考虑在嫁接苗栽培区推广应用。     

Damage Analysis of Hanshin Expressway Viaducts during 1995 Kobe Earthquake. III: Three-Span Continuous Girder Bridges

Almost all the single reinforced concrete (RC) piers from P35 to P350 received consistently severe damage, considering the large residual inclination of piers included in earthquake-induced severe damage. However, some of the piers in the section from P35 to P350 remained lightly damaged, and this phenomenon is observed especially in many piers under fixed bearings in continuous girder bridges. In this study, using experimentally based models for metal bearings and installing them to an existing FEM code, a nonlinear dynamic response analysis of a continuous girder bridge system is conducted. It is shown that the results depend on the ground motion, but the fuse effect of the breaking of the bearings could have been a reason for the phenomenon.