气体钻井井斜有限元岩石应力分析

气体钻井易井斜,钻井施工主要通过调整钻具组合和钻井参数进行轨迹控制,然而在高陡构造地区,气体钻井井斜变化严重超出井身质量控制要求,为后期作业带来了严重影响。因此,气体钻井井斜变化必须考虑井筒中不同循环介质的影响和井壁稳定程度的影响,而现有的数学模型复杂,计算量大,不能真实地模拟井下钻井的力学变化。为此,利用有限元理论,建立了实体三维力学模型,可以充分考虑井筒中不同循环介质的影响和井壁稳定性的影响进行Von Mises应力计算,根据地层应力值的变化,可以直观地分析出气体钻井井斜规律。通过对该模型力学计算结果的分析表明：在相同地层倾角和岩石强度下,气体钻井井斜幅度大于钻井液钻井的井斜幅度,井壁更不稳定,钻井时更易出现井眼扩大现象;当地层倾角小于45°时,井斜具有上倾趋势;地层倾角等于45°时,井斜趋势不明显;地层倾角大于45°时,井斜具有下倾趋势。     

Highly active and durable FexCuyNi1-x-y/FeOOH/NiOOH/CuO complex oxides for oxygen evolution reaction in alkaline media

Oxygen evolution reaction (OER) catalyzed by Ru/Ir-free electrocatalysts is pivotal for preparing oxygen in efficient way, yet our understanding of the relationship between microphysical properties and OER performance is still insufficient. Here we report on 41 kinds of Fe_xCu_yNi_1-x-y/FeOOH/NiOOH/CuO complexes (FCN-x) to investigate the Cu and Fe induced electronic perturbation and what it brings to OER performance. As result, the activity mapping of FCN-x shows an optimal composition of 1:2:7 (FCN-7) showing a comparable overpotential potential of 170.3 mV, Tafel slop of 75.9 mV dec^?1 and durability of 24 h (～29% activity loss) to that of mainstream Ru/Ir-free catalysts. Such enhancement could be attributed to the role of alloying contribution of Fe/Cu, electronic perturbation and surface modification of surface oxides. Additionally, the incompletely oxidized Fe_xCu_yNi_1-x-y not only provide a platform for electron conduction, but also work as a sacrificial material to forming fresh oxides to maintain the content of surface oxides, which is a key driver of the excellent durability of FCN-7. This synthetic strategy may give an effective way to design and screen Ru/Ir-free OER catalysts.     

QL1井井底突发性岩爆动力学机理及动态演化过程

氮气钻井钻遇致密砂岩高压裂缝圈闭导致井底岩爆是四川盆地西部白马庙构造QL1井恶性井喷事故的根本诱因。利用研究井壁失稳的理论方法来进行井底岩爆的动力学机理分析,并借助Visual Basic语言和Matlab软件编程,进行了岩爆的动态演化模拟。研究认为,当井底逐渐接近高压裂缝圈闭的过程中,裂缝面周向应力和径向应力差值逐渐增大,主应力之间的差值所引起的剪应力增长使裂缝面产生压剪破坏及压剪-拉伸复合破坏,直至破坏区连通井筒,高压气体携带大量碎屑喷入井内,释放大量能量,产生井底岩爆。该研究成果系统解释了QL1井录井监测参数的异常变化,其研究结果不仅可为岩爆的防治提供理论基础,而且在石油工程领域为深部岩体动力学失稳研究提供了一个新的视角。     

塔中Ⅰ号坡折带上奥陶统礁滩相特征及其对储层的控制

研究区上奥陶统良里塔格组沉积时期发育生物礁、灰泥丘、粒屑滩等亚相,这些亚微相组合成的礁(丘)滩复合体已发育.礁滩体的横向变化特征总体上表现为沿I号坡折带发育礁滩复合体.内侧主要形成丘滩复合体.储层发育受礁型微地貌影响明显,高能相带的礁滩体有利于储层的发育.礁型微地貌控制着储层发育的层位性与区域差异性.     

倾斜大管径拟单相流气井井底流压计算

在前人对气井拟单相管流研究的基础上,结合井筒温度场分布模型,推导考虑动能项及摩阻影响的管流压降模型,可计算倾斜大管径拟单相流气井井底流压值。实例计算结果与压力计测试值平均绝对偏差仅为0．44％,满足工程误差范围要求,该模型可用于此类气井的井底流压计算。     

数字化气田远程监控体系结构研究

针对数字化油气田数据采集、传输和信息共享问题,结合工控网络、局域网、Intemet／Intranet及无线通信网络技术,采用TCP/IP、WAP、SOAP等通信协议和分布式对象技术,提出了自动化采集和PDA相结合,移动公网与VPN相结合,Web与WAP结合,DCOM与Web Service结合以及E-mail／手机短信／寻呼结合的数字化气田远程监控体系结构,详细分析了所用到的关键技术,为油气田数字化建设远程监控提供了一种综合解决方案。     

压裂液助排剂GCY-3的研制及室内评价

针对压裂液返排造成的地层伤害问题,采用季铵盐阳离子表面活性剂及醇复配了一种价格低廉、制作工艺简单的压裂液助排剂GCY-3,确定了其最佳配方。依据行业标准对该助排剂进行室内评价,结果表明,GCY-3具有较高的表面活性和良好的热稳定性,它不仅降低了破胶液的表面张力,还能提高川西常用压裂液的抗剪切能力。     

元坝地区陆相地层钻井提速配套技术

四川盆地元坝气田天然气资源丰富,是中国石化的重点勘探开发区块,但钻速慢、钻井周期长是该区深井-超深井所面临的共同难题,该区域陆相侏罗系沙溪庙组-三叠系须家河组地层岩石致密、硬度高、可钻性差,此井段钻井周期约200 d,占全井钻井周期的45%,严重制约了钻井提速提效。为此,开展了扭力冲击器配合PDC钻头、涡轮配合孕镶金刚石钻头、气体钻井等新技术应用试验,在试验效果的技术经济分析基础上,提出了延长气体钻井应用井段和深度的方案;对于不宜开展气体钻井的钻井液井段,如侏罗系自流井组中上部以浅地层或钻井液密度较低的地层推荐采用扭力冲击器提速,自流井组中下部-须家河组地层推荐应用涡轮钻具提速的方案。YB27-1H等11口井第三次开钻的Φ314.1 mm井段平均进尺1 885.29 m,钻井周期缩短到166.18 d,较前期平均值缩短34 d。采用上述配套技术后,无论是钻井周期、日进尺均优于前期施工井,陆相地层提速提效取得了显著效果。     

An artificial neural network for predicting the friction coefficient of deposited Cr1−xAlxC films

This paper applies a generalized regression neural network (GRNN) for predicting the friction coefficient of deposited Cr_1−xAl_xC films on high-speed steel substrates via direct current magnetron sputtering systems. The Cr_1−xAl_xC films exhibited some excellent characteristics, such as low friction coefficient, high hardness, and large contact angle. In this study, a GRNN model is applied for predicting the friction coefficient of Cr_1−xAl_xC films on high-speed steel substrates instead of complex practical experiments. The results exhibit good prediction accuracy of friction coefficient since about ±0.97% average errors and show the feasibility of the prediction model. Compared to the conventional back propagation model, the GRNN model is more suitable to predict the friction coefficient of Cr_1−xAl_xC films.     

Flow mechanism of 9Cr18 steel during thixoforging and its properties for functionally graded material

The thixoforging of 9Cr18 steel was investigated and flow mechanism was explained. In this paper, microstructure of the thixoforged specimen was observed by optical microscope (OM). Hardness and wear resistance of different areas in thixoforged specimen were compared with conventional specimen. The results showed that thixotropic behavior under low strain rate was obviously influenced by deformation time. It was indicated that a functionally graded material (FGM) with changes of microstructure and properties could be fabricated through thixoforging process. During thixoforging process, melted liquid gathered and flew through several channels to minimize barrier and critical amount of deformation was required to form a FGM structure. The wear resistance of the thixoforged specimen was improved due to a wear-resisting skin layer that surrounded outside.