Synthesis and performance evaluation of a new drag reducer based on acrylamide/12-allyloxydodecyl acid sodium

Hydraulic fracturing with slickwater is a field-proven stimulation technology used in tight reservoirs. Because of the high pumping rate associated with slickwater fracturing, drag reduction (DR) is critical in minimizing pressure drop and the success of oilfield operations. In this paper, a new type of drag reducer (SPR) was synthesized with acrylamide and 12-allyloxydodecyl acid sodium, and its drag reduction performance was evaluated. The results showed that the new drag reducer features low molecular weight, fast-dissolving rate and low interfacial tension. The algorithm of estimating the drag reduction rate of non-Newtonian fluid SPR was proposed and validated. Empirical or semianalytical models for estimating the friction ratio (σ) or friction factor (λ or f) were used to simulate the turbulence behavior of the SPR drag reducer under different Reynolds numbers (Re). The modified Virk's correlation could accurately model the turbulent behavior of the SPR drag reducer. A unified calculation formula was established in this study for different pipe diameters.     

轧机锁紧油缸泄漏原因分析及系统改进

济钢第一小型轧钢厂轧机液压换槽系统因工作压力增高，蓄能器压力油长期作用于锁紧缸，引起密封圈击穿、泄漏和机架不稳。通过增设定值减压阀控制油压，改进锁紧油缸结构，解决了锁紧油缸的泄漏问题，保证了轧制线的稳定，轧机作业率由85％提高到87％。     

防止减速器“跑,冒,漏”油的几种新方法

介绍了防止减速器“跑，冒，漏”油的几种新方法。     

井下减速器传动方案分析

结合井下减速器的结构特点，分析了定轴轮系传动、2K-H型行星轮系传动、3K行星轮系传动、少齿差行星轮系传动4种传动方案，选择内齿作为输出轴的少齿差行星轮系传动方案更符合涡轮钻具的传动要求和井下工具结构特点。少齿差行星轮系的研制、开发、应用可降低涡轮钻具转速，提高扭矩，提高深井钻速。     

东濮凹陷低阻油层成因研究

针对东濮凹陷低阻油层的测井曲线显示特征，从岩石物理特性、油藏高度、泥质砂岩阳离子交换、换井滤液侵入和导电矿物影响等几个方面系统地进行了低阻油层成因研究。研究结果表明，东濮凹陷伏阻油层的形成是多种因素共同作用的结果，但骨架颗粒岩性细、泥质含量偏重、地层水矿化度高，油藏高度低是形成东濮凹陷低阻油层的主要因素。     

浅谈电动潜油单螺杆采油系统的研究开发

介绍了国内外各种螺杆泵采油系统的发展现状，并对电动潜油螺杆泵采油系统中齿轮减速器这一关键部件的方案选择进行了分析，旨在为研制开发国产高性能电动潜油螺杆采油系统提供参考。     

黄原胶接枝共聚物降滤失剂应用性能评价

黄原胶（XG）具有优良的耐盐性和增稠降滤失性能，但耐温性较差。对XG分子结构的分析认为，可利用XG链上的活泼基团接枝丙烯酰胺等乙烯基单体，增强其耐温性能，用作耐温抗盐钻井液处理剂。对比了合成的黄原胶丙烯酰胺等接枝共聚物（XGG）降滤失剂与XG在淡水、4％盐水和饱和盐水钻井液中的增粘降滤失性能和抗温性能，并通过岩心膨胀试验对比了XGG、XG和KCl对页岩的抑制性能。试验结果表明，在淡水钻井液中XGG具有极强的增粘效果和降滤失能力，远远超过XG1随着钻井液矿化度的提高，XGG的性能有一定下降，但XGG在各种钻井液中均具有比XG更好的高温增稠和控制失水的能力；XG已具有优良的抑制性，XGG的抑制性得到进一步提高。     

Metallurgical Investigation of a Prematurely Failed Concentric Reducer Tube Used in a Hot-Rolling Mill

A concentric reducer tube, which was a part of the top exit roughing hydraulic descaler in a hot strip mill failed prematurely under working pressure. A detailed metallurgical investigation comprising physical examination, optical microscopy, scanning electron microscopy, and electron probe microanalysis was carried out to find out the genesis of the failure. Physical examination revealed cracks located symmetrically around the circumference of the tube that ran along its full length, up to the weld beads at both ends. Optical microscopy of etched samples revealed a banded ferrite-pearlite structure and the existence of forging folds near the change-in-section(160° fillets). Cracks were found to initiate from these forging folds. No structural abnormalities were found in the weld beads and heat-affected zones.     

抽油机球铁齿轮的化学成分及生产工艺

为提高抽油机减速器齿轮铸件的机械性能，提出以Sn代替Mo作为合金元素，并通过试验确定了合理的Si、Cu、Sn的加入量。指出Si加入量应控制在1．9％－2．1％范围内，同时加入0．36％～0．9％的Cu和0．025％～0．07％的Sn，可保证球铁的强度和延伸率都满足QT700－2的要求。鉴于试件与实际铸件的表面硬度有一定的差值，为提高铸件表面硬度，进行了余热正火试验，并给出了铸件在铸型内的时间－冷却温度曲线。最后根据球铁化学成分的选择结果，进行了齿轮生产试验。     

悬臂式掘进机截割臂互换性设计

针对现有掘进机多采用单一的横轴式或者纵轴式整机,对不同岩层掘进工作的适应能力差等问题,提出一种面向不同岩层的掘进机截割臂互换性设计方案。对纵、横轴式2种掘进机的结构特点与性能进行了对比分析;针对2种截割臂工作模式的特点,分别设计了相应的截割减速器。Solidworks仿真结果表明,与单一横轴式或者纵轴式掘进机相比,采用互换式截割臂结构可有效提高掘进机对不同岩层截割工作的适应能力,提高掘进效率,节省设备运输及使用成本。