普光大湾地区断裂系统自动识别及裂缝建模研究

作为典型的裂缝孔隙型气藏,裂缝系统的识别和表征对于普光气田大湾区块产能建设和后期开发具有至关重要的意义。但是,该区块在逆断裂发育背景下,裂缝发育,非均质性更强,利用已知分属各断块的井预测井间、其他断块的储层属性也变得更加困难。为此,本文采用多学科协同分析方法,综合利用地震、钻井、测井、地质资料和研究成果,应用断裂系统自动分析技术和离散裂缝网格建模技术,采用确定性建模和随机性建模相结合的方法,建立了大湾气藏储层段飞仙关组、长兴组的离散裂缝模型,表征了裂缝的纵向、横向分布特征,实现了对储层裂缝系统精确、定量的描述,为气田下步开发研究提供了有效指导。     

基于Park-HHT的故障特征提取方法

针对三相对称系统,提出了一种新的故障特征提取方法。该方法首先将系统输出信号进行Park变换,之后进行希尔伯特-黄变换(Hilbert-Huang transform, HHT),从HHT的本征模态函数中选取低频分量,提取信号幅度作为故障特征值。该方法兼具Park变换和HHT的优点,在降低变量维度的同时提高了故障分辨率,并且具有较强的抗噪声能力。最后,在三相逆变电路中进行了仿真实验,根据特征向量间距离分布对不同方法的提取效果进行评价,验证了所提方法的有效性。     

基于PETRI网递阶监控器的间歇过程故障诊断

基于混杂系统理论的Petri网递阶监控器设计方法,对间歇过程的故障传播和诊断进行了研究,建立了具有两层递阶结构的Petri网故障诊断系统,上层采用赋时Petri网协调间歇时序操作步骤,下层采用混合模糊Petri网进行故障监测和诊断.针对一个实验级应用例子建立了故障传播和诊断的混合模糊Petri网模型,实验和仿真结果表明了方案的可行性和有效性.     

模拟电路软故障诊断测试节点优选的仿真研究

基于斜率故障模型和线性相关系数故障模型,提出了一种模拟电路软故障诊断字典法中的测试节点优选算法.针对模拟电路中的单故障和双故障,分别利用节点电压增量计算出的斜率和线性相关系数作为统一故障特征,建立故障字典;给出了在字典建立过程中,利用PSPICE仿真工具对电路进行故障仿真,采用特征函数描述故障统一特征的差别,根据故障隔离度优选测试节点的算法和步骤;并用仿真实例验证了该测试节点优选方法的有效性.     

基于信息熵的纵列式无人直升机故障树诊断

研究纵列式无人直升机故障诊断问题.首先根据其操纵控制系统的结构特征,建立操纵控制故障树及故障传播矩阵.其次运用信息熵决策推理方法,分析样本测量与信息不足引起的不确定决策,进行故障树不确定性推理,并确定故障节点重要度及隶属关系.最后根据二元假设检验,进行故障判定.并针对直升机尾传动轴不对中故障,引起振动与作动器效能降低,进行仿真与实验,验证该故障诊断方法的可行性与有效性.     

Slip rate along the Lijiang-Ninglang fault zone estimated from repeating microearthquakes

Seismicity and slip rates along the Lijiang-Ninglang fault zone between 1999 and 2006 were investigated with the waveform data recorded by the Yunnan digital Seismic Network. The relocated seismicity by the double difference method clearly exhibits different features between the northern and southern segments. More than 76% earthquakes occurred in the southern segment of the fault near the Lijiang area. The relocated seismicity appears to reflect the crustal velocity structure of the study area. Using cross-correlation analysis, we identified a total of 92 doublets and 70 multiplets that show high waveform similarity. Most of these sequences are aperiodic with recurrence intervals varying from a few minutes to hundreds of days. Using two sequences that occurred regularly over the study period, we obtained a fault slip rate of approximately 5 mm/a at ∼23 km, in good agreement with geologic and surface GPS measurement. Supported by National Basic Research Program of China (Grant No. 2004CB418405) and National Natural Science Foundation of China (Grant No. 40174014)     

On the measurement of slip length for liquid flow over super-hydrophobic surface

To design a surface with large slip or larger drag reduction is a pop issue in the fields of liquid transporting and body swimming. In this context, it is a crucial problem to measure the slip length for these surfaces. Here we propose a novel method by using rheometer for this objective. This method is implemented by designing the distribution of the super-hydrophobic area on the sample. Using this method, a slip length of 40 μm for 70 wt% glycerin flow over a super-hydrophobic surface with stripe structure （the period, width and height of ridges are 150 μm, 40 μm and 65 μm, respectively） is measured. The result shows that the slip length measured using this method is in good agreement with former results measured by other methods. This method is fit for measuring the slip length of super-hydrophobic surface whose structure ranges from microto nano-scale.     

Robust fault detection and diagnosis for uncertain nonlinear systems

This paper considers robust fault detection and diagnosis for input uncertain nonlinear systems. It proposes a multi-objective fault detection criterion so that the fault residual is sensitive to the fault but insensitive to the uncertainty as much as possible. Then the paper solves the proposed criterion by maximizing the smallest singular value of the transformation from faults to fault detection residuals while minimizing the largest singular value of the transformation from input uncertainty to the fault detection residuals. This method is applied to an aircraft which has a fault in the left elevator or rudder. The simulation results show the proposed method can detect the control surface failures rapidly and efficiently.     

新甘交界北山地区大泉断裂走滑特征及ESR测年证据

卫星图片显示穿过大泉断裂的水系有被左行扭曲的特征,结合野外断层面上擦痕、断裂带中劈理观测统计和室内对断层岩显微构造的分析,确定了大泉断裂是以左行为主的走滑断裂带。对断层泥的ESR年代学测定,确定了大泉断裂开始活动时间为早更新世1.2～1.5Ma,其分支断层的活动时间在晚更新世300ka左右。大泉断裂活动时间与青藏高原在上新世末-早更新世初开始强烈隆升时间一致,表明大泉断裂的形成与青藏高原的隆升过程密切相关,是晚新生代印度和欧亚两大板块持续碰撞挤压和青藏高原隆升的远程效应。     

徐家围子断陷营一段火山岩旋回测井响应特征

在钻井取芯研究的基础上,应用测井资料,开展了松辽盆地北部徐家围子断陷营城组营一段高分辨火山岩旋回的划分,建立了营一段火山岩的旋回模式,并总结了营城组一段不同岩性、岩相的测井响应特征。研究结果表明,营一段划分为3个旋回,每个火山岩旋回的自然伽马和电阻率曲线值在底部一般为中高值,顶部为低值;在不同旋回界面,测井曲线振幅和变化频率明显增大,指示风化壳或沉积夹层等标志性界面的存在;并通过研究认为自然伽马、电阻率和密度3种测井曲线对火山岩岩性和岩相识别最为敏感。