MEMS加速度传感器在矿用随钻轨迹测量系统中的误差校正

矿用随钻轨迹测量系统的工具面向角和倾角通常采用加速度传感器实现测量,然而由于传感器制作工艺、探管机械加工以及装配等因素使得工具面向角和倾角的测量出现误差。为了修正上述系统误差,首先介绍了随钻轨迹测量系统及其工作原理,进而分析了加速度传感器的误差产生,并建立了MEMS加速度传感器的误差模型;提出了一种基于三十六位置的加速度标定方法,并对其进行相应的测试。实验结果表明:建立的加速度误差模型在随钻轨迹测量系统中,倾角精度为0.2°,工具面向角精度为0.2°,且倾角和工具面向角之间相互影响较小,能够满足实际煤矿井下钻探工艺的精度需求。      

定向仪用差动调角器和量角器

受控定向钻探中，现有的随钻定向仪一般采用360°全方位测量的方式。提高在小顶角下的测量精度不但困难，而且传感器结构复杂，成本高。由于受控定向钻探中每一回次中设计工具面向角是一定的，钻进中不会发生很大的变化。因此，随钻定向仪只需在设计方位及其附近精测，其它方位可以粗测，不必采取360°全方位的测量方式。为了使定向仪在任意设计工具面向角下都能精测，可以在定向仪上装调角器，其作用是调整楔形定位器与工具面向角传感器之间的夹角。一般定向仪探管直径很小（35mm左右），为准确而方便地调整角     

回转钻进随钻测斜仪的研制及应用

针对煤矿井下常规钻机回转钻进没有随钻轨迹测量装备的现状,研制了钻孔随钻测斜仪。该仪器主要由孔口显示控制器和轨迹记录探管两部分组成,可用于煤矿井下常规钻机回转钻进钻孔的轨迹测量,亦可测量钻孔的倾角、方位角和工具面向角等姿态参数,孔口显示控制器同步工作并记录钻孔的深度和测量时间。最终结果可通过数据处理软件计算和处理原始数据并在井下以数字和图形的方式显示出来,满足了煤矿井下常规钻机的回转钻进随钻测量需求。      

基于MEMS陀螺传感的测斜仪研制

针对目前矿井钻探的钻孔轨迹测量存在高温、高能耗问题,提出了间歇供电的无缆存储式测斜仪。硬件上采用MEMS陀螺仪和加速度传感器,软件上采用抗干扰、误差修正、温度补偿等校正措施。可用于地质灾害监测的成孔测量并记录方位角、倾角、工具面角、孔深等姿态参数。测量后,由上位机读出数据,显示轨迹图形。经仿真与模拟测试,该测斜仪具有功耗低、体积小、测量精度高、稳定性好等优点。      

双轴倾角传感器在钻孔测斜仪中测量算法的校正

将芬兰VTI公司生产的SCA100T双轴倾角传感器应用于钻孔测斜仪,其体积小,能提高倾角测量的稳定性和精度。双轴倾角传感器测量角度会引起算法校正问题,采用测得的标定数据得出倾角值的回归模型,测量倾角的实验结果和推算结果存在一定的误差,通过应用误差补偿方法来减小实际测量误差。理论分析和仿真计算表明,采用此法补偿后得到的均方差最大为0.15258,而没有补偿的结果最大均方差为4.81104。      

高温钻孔测斜仪研制

针对高温高压干热岩钻井定位轨迹探测设备存在耐高温高压性能差、稳定性差、测量精度不高、电能消耗大等问题,研制一套高温钻孔测斜装置,解决高温高压多点连续钻孔测斜及测温问题。选择耐高温元器件,设计控制和测量电路;采用自动间歇供电方法,减少散热,降低功耗;设计保温探管、承压探管,利用ANSYS有限元软件对承压外管的屈服强度和保温探管的温度场与压力场进行耦合分析和校核。最后进行仿真测试和野外试验,根据测试数据表明,设备能在280℃和12 MPa高温高压环境条件下实现深井倾角、方位角、工具面向角及温度的测量。      

存储式光纤陀螺测斜探管研制

本文介绍的“存储式光纤陀螺测斜探管”主要解决超高温大井深环境下钻孔轨迹测量“测斜探管”问题,它包括钻孔各孔深井段倾角、方位角、工具面向角及温度的测量。目标是攻克光纤陀螺传感器温度漂移、光纤陀螺惯测组合井下环境适应性、仪器外场标定技术和误差分析校正等关键技术,研制的超高温钻孔轨迹测量仪,使用环境温度可达270 ℃,环境压力120 MPa,通过在高温地热能钻探工程、干热岩钻探工程、科学钻探工程、深部矿产资源勘探和深部油气资源勘探等工程中的应用,拓展应用领域,为超高温大深度钻井轨迹测量提供技术支撑。     

矿用随钻动态方位伽马仪器的研制与应用

顺煤层瓦斯抽采钻孔是目前最直接最有效的瓦斯治理方法,自然伽马作为含煤地层识别常用的判识依据,可以根据地层放射性判断钻孔轨迹是否在目标层中。但现有的矿用伽马测井仪器只能进行滑动钻进测量,不适用于复合钻进及旋转导向钻进,无法满足伽马动态连续测量的工况。针对以上问题,在分析了煤矿井下随钻测量工况特点和伽马测井原理的基础上,通过低压直流载波双向通信技术进行孔底多扇区方位伽马数据的实时传输;采用屏蔽开窗的结构设计,实现单伽马晶体的8扇区分区测量;基于三轴MEMS加速度传感器和三轴MEMS陀螺仪不同的频率特性,采用互补滤波的动态测量方法,克服了回转钻进过程中振动和旋转对工具面向角测量的影响。通过地面性能测试和井下的工业性试验,验证了仪器在不同放射性地层分界面能正确反映出地层放射性变化规律。试验结果表明,仪器可以满足复合回转定向钻进时的地质导向测量要求,为煤矿井下顺煤层定向钻进提供了技术保障。      

基于抗转模型的颗粒材料宏−细观关系研究

接触模型的宏?细观参数标定是成功使用离散元方法的关键。在离散元的接触模型中线性接触模型与抗转线性接触模型均可用于模拟砂性土的力学行为,其中抗转线性接触模型在模拟密砂的剪胀性方面具备优势。采用抗转线性接触模型对室内密实砂土三轴试验进行了离散元模拟,验证了抗转线性接触模型的可靠性;进而系统分析了颗粒间摩擦系数、刚度比和抗转动系数等细观参数与砂土峰值内摩擦角、残余内摩擦角、峰值剪胀角等宏观参数的相关关系并进行了验证;揭示了偏应力作用下,细观参数对密实砂土试样内部剪切带宽度与倾角变化的影响规律,提出了考虑剪胀角的剪切带倾角经验公式。通过研究建立了抗转线性接触模型宏?细观参数的量化关系并给出了标定参数的具体流程图,提出了快速标定宏观参数的方法并应用实例进行了验证,为采用抗转线性接触模型精准模拟密实砂土的力学特性提供依据。     

岩心倾角卡尺及其使用方法

<正> 通常用三角板配合量角器测量岩心的倾角。这种方法不仅操作不便,而且误差较大。为了避免岩心倾角测量中的弊病,提高测量精度,寻求一种简单准确的岩心倾角测量方法,是完全必要的。下面要谈到的岩心倾角卡尺(简称卡尺),就是根据公式tga=y/x 的原理,制成的一种岩心倾角量具。     

Simple monitoring method for precaution of landslides watching tilting and water contents on slopes surface

A low-cost and simple monitoring method for early warning of landslides is proposed. To detect abnormal deformation of a slope, this method employs a tilt sensor in place of an extensometer on the slope surface. In order to examine the relevance of measuring rotation angle on a slope surface by tilt sensor, model tests were conducted, and rotation on the slope surface was observed together with slide displacement along the surface. The rotation data responded 30 min before failure in a model test, which could be useful as a signal for early warning. However, the behavior of rotation before failure varies from case to case, and thus, criteria to issue warning should be defined more carefully. For a model slope made of uniform loose sand, measurement of slide displacement along the slope surface is sensitive to failure at the toe, while the measurement of rotation on the slope surface is useful to detect the development of progressive failure upward along the slope. Wireless sensor units with microelectromechanical systems (MEMS) tilt sensor and volumetric water content sensor were also examined on a real slope in Kobe City, and a long-term monitoring was attempted. A simple but possible way to define the criteria of judgment to issue warning can be proposed based on combination of data obtained by the tilt sensors and volumetric water content sensors.     

Risk evaluation and warning threshold of unstable slope using tilting sensor array

Slope monitoring and early warning systems are a promising approach toward mitigating landslide-induced disasters. Many large-scale sediment disasters result in the destruction of infrastructure and loss of human life. The mitigation of vulnerability to slope and landslide hazards will benefit significantly from early warning alerts. The authors have been developing monitoring technology that uses a micro-electro-mechanical systems tilt sensor array that detects the precursory movement of vulnerable slopes and informs the issuance of emergency caution and warning alerts. In this regard, the determination of alarm thresholds is very important. Although previous studies have investigated the recording of threshold values by an extensometer which installation of an extensometer at appropriate sites is also difficult. The authors prefer tilt sensors and have proposed a novel threshold for the tilt angle, which was validated in this study. This threshold has an interesting similarity to previously reported viscous models. Additionally, multi-point monitoring has recently emerged and allows for many sensors to be deployed at vulnerable slopes without disregarding the slope’s precursory local behavior. With this new technology, the detailed spatial and temporal variation of the behavior of vulnerable slopes can be determined as the displacement proceeds toward failure.

     

Comparison of Different Techniques of Tilt Testing and Basic Friction Angle Variability Assessment

A relevant parameter for estimating discontinuity shear strength is the basic friction angle, usually derived from different types of tilt tests. However, the tilt tests described in the literature produce varying basic friction angle values. From a large number of different types of tilt tests on different kinds of rocks, it was possible to conclude that the mechanisms of sliding along cylinder generatrixes and planar surfaces are quite different, and that tests based on sliding along generatrixes are not appropriate for determining reliable basic friction angle values for discontinuity planes. Tests on small specimens are also not recommended, for geometry reasons and because ensuring reliable stress conditions is difficult. To quantify the natural variability in tilt testing, large specimens of the same granite were tested. The results revealed coefficients of variation for the basic friction angle in the range of 5–10?%, a variability which is no greater than that found for other rock mechanics parameters. This observation enables to forward some recommendations concerning the appropriate number of tests needed to obtain reliable results.     

倾斜检波器与地表双自由度耦合效应

煤田地震数据采集过程中，存在同一检波点位置重复插拔布设检波器的情况，检波器多次插拔布设存在倾角差异，导致检波器与地表耦合条件变化，影响地震数据采集质量。将检波器倾角参数引入检波器与地表耦合系统。从振动力学的角度推导倾斜检波器“双自由度耦合振动系统”，研究检波器倾角、检波器与地表相对阻尼系数、地表介质参数对耦合系统的影响，分析相同检波点位置重复布设检波器对地震数据采集的影响机理。研究结果表明，检波器倾角的增加将衰减检波器与地表耦合系统的幅频响应，提高耦合系统的谐振频率，说明本次倾斜检波器与地表耦合系统模型构建合理，结果可用于指导和规范地震数据采集工作。      

倾斜布管采控天然冷量的青藏铁路路基温度场演变规律

Aiming at the stabilization of Qinghai-Tibetan Railway embankment during its construction and run, the method using tilt pipes to keep the permafrost embankment stabilization is put forward in the paper. By gathering natural cold energy in the winter and release it in the summer the tilt pipes can keep the permafrost embankment stabilizing. The temperature fields of the embankment and the stratums below are studied according to the condition of pipes diameter 250mm, length 7. 0m and tilt angle 30°,45°, 60° until the railway working for 20 years. It is shown that the embankment field using tilt pipes will eliminate the thawing core and come into subzero temperature phase ahead of 9 years compared with the original model. Different tilt angles have different efforts on the embankment and stratums, synthesis analysis of thermal income and expenses of the embankment and stratums should be carried out     

Laboratory simulation to understand translational soil slides and establish movement criteria using wireless IMU sensors

Landslide monitoring and warning using inertial measurement units (IMUs) has shown the potential for remote and real-time applications. However, the studies conducted using the IMU sensors are limited to rainfall-induced landslide detection using soil moisture sensors and accelerometers for predicting slide and measuring tilt, respectively. The tilting of the slope might not occur during a slow-moving translational slide, and it may not always be possible to accurately record the soil moisture condition. The use of raw acceleration data, which is the combination of linear and gravitational accelerations, for calculating tilt or motion is another drawback of the existing studies. Hence, there is a need for a better approach to monitor slides. This paper presents two methods to define movement thresholds and criteria to identify the translational soil slides based on our understanding of the sensor data recorded during the two laboratory experiments. BNO055 sensor devices (IMU sensors) with 3-axis accelerometers and 3-axis gyroscopes were selected for this study. The linear accelerations, gravitational accelerations, and angular velocities were utilized to understand the translational soil slides by correlating the sensor behavior to that of the slope. The interpretation of the movements during the failure at each sensor location was further verified by referring to the videos recorded by two pi-cameras. The outcomes of this study confirm the applicability of the proposed IMU sensor system and the movement thresholds for effective and reliable monitoring and warning of translational soil slides.     

土质滑坡地表倾斜变形特征与基于MEMS的倾斜变形监测技术初探

随着现代信息技术快速发展,人们获取滑坡现场各类监测信息的能力越来越强,积累的现场监测数据也愈来愈多,如何充分、精细化地利用监测数据已成为滑坡监测预警工作中重点关注的问题。为此,本文以土质滑坡为研究对象,采用强度折减有限元方法开展地表倾斜变形时空演化特征理论研究,发现地表倾斜变形在滑动面扩展至贯通期间出现"速率排序跃迁"现象,在滑动面贯通后出现"速率突变"现象。采用地表倾斜变形与内部滑动面之间的这种定量化关联特性,可以为土质滑坡中短期预测预报方法研究提供新的视角和方向。利用理论研究成果,本文进一步开展地表倾斜变形监测关键技术研究,讨论基于MEMS加速度计的倾角传感器的测量原理与测量精度,分析环境温差波动对倾角测量误差的影响,最后介绍基于竖直倾角测量方式研制的普适型滑坡地表倾斜变形监测设备——坡体浅层倾斜变形测量仪。     

Aeromagnetic study of buried basement structures and lineaments of Sahel region (Eastern Tunisia,North Africa)

This study presents original results regarding the use of aeromagnetic to explore deep subsurface structuring in southern part of Tunisian Sahel petroleum province (Eastern Tunisia, North Africa). Several filters and techniques were applied to the total magnetic intensity (TMI) grid. First, an adequate reduce to the pole (RTP) grid was generated. The RTP map shows 17 positive and negative anomalies associated with short- and long-wavelength amplitude anomalies. Positive anomalies correspond to high magnetic basement structures estimated from seismic lines in the area. Circular anomalies are also distinguished locally and can be explained by Cretaceous magmatic rocks recognized in numerous petroleum wells. Second, specific qualitative and quantitative filters (e.g., residual-regional separation, horizontal tilt angle (TDX), tilt angle (TILT), total horizontal derivative of tilt angle (THDTILT)) were applied to elucidate the form and the extent of buried magnetic anomalies and lineaments. The resulting deep structural map revealed the presence of NW-SE, N-S, and E-W regional magnetic basement structures and lineaments and a regional tectonic node surrounding Henchir Keskes-Agareb-Mahres-Hachichina area. Two magnetic inversion models calculated across the study area highlight west to east crustal thinning trend and permit depth to basement estimation. These results are valuable for future conventional and unconventional petroleum exploration in this underexplored southern part of Sahel plain.     

各向异性砂岩冻融力学特性研究

针对新疆天山公路岩质边坡的砂岩, 开展了单/三轴压缩试验和不同次数的冻融循环试验, 探讨了岩样强度和变形参数的各向异性随围压和冻融循环次数的变化规律, 分析了层理角度及冻融作用对岩样破坏模式的影响。结果表明： 岩样的弹性模量、 黏聚力、 内摩擦角和峰值强度均随着层理角度的增加呈现先减小后增加的U型发展态势, 在60°时达到最小值, 在0°或90°时其值最大; 岩样的强度以及变形参数随着冻融循环次数的增加逐渐减小, 随着围压的增加而增大; 不同层理角度岩样强度及力学参数的差异性随着围压的增加逐渐较小, 相应的岩样各向异性特性逐渐减弱; 随着冻融循环次数的增加, 岩样内部的裂纹不断扩展导致岩样各向异性程度逐渐增强; 不同层理角度岩样的破坏模式可归纳为穿越基质和层理面的竖向劈裂张拉破坏、 穿越基质和层理弱面的剪切破坏、 拉-剪混合破坏、 沿层理弱面的剪切滑移破坏、 沿层理弱面的竖向劈裂破坏等5种模式。研究成果可为寒区岩体工程相关研究提供参考和依据。