泥晶灰岩地层孔壁坍塌掉块现象及处理

在灰岩地区钻探施工过程中，常见孔壁坍塌、掉块现象，尤其在含泥晶灰岩地层分布区钻进过程中，这种现象尤为突出，轻则影响钻探施工效率，重则造成钻探孔内事故。针对孔内坍塌、掉块现象的征兆及特点，提出了相对应的处理办法。     

Monitoring of Over Cutting Area and Lubrication Distribution in a Large Slurry Pipe Jacking Operation

Slurry pipe jacking was firmly established as a special method for the non-disruptive construction of the underground pipelines of sewage systems. Pipe jacking, in its traditional form, has occasionally been used for short railways, roads, rivers, and other projects. Basically the system involves the pushing or thrusting of concrete pipes into the ground by a number of jacks. In slurry pipe jacking, during the pushing process, mud slurry and lubricant are injected into the face and the over cutting area that is between the concrete pipes and the surrounding soil. Next, the slurry fills voids and the soil stabilizes due to the created slurry cake around the pipes. Fillings also reduce the jacking force or thrust during operation. When the drivage and pushing processes are finished, a mortar injection into the over cutting area is carried out in order to maintain permanent stability of the surrounding soil and the over cutting area. Successful lubrication around the pipes is extremely important in a large diameter slurry pipe jacking operation. Control of lubrication and gaps between pipes and soil can prevent hazards such as surface settlement and increases in thrust. Also, to find voids around the pipes after the jacking process, in order to inject mortar for permanent stabilizing, an investigation around the pipes is necessary. To meet these aims, this paper is concerned with the utilization of known methods such as the GPR (Ground Penetrating Radar) system and borehole camera to maintain control of the over cutting area and lubricant distribution around the pipes during a site investigation. From this point of view, experiments were carried out during a tunnel construction using one of the largest cases of slurry pipe jacking in Fujisawa city, Japan. The advantages and disadvantages of each system were clarified during the tests.     

A New Nonparametric Discriminant Analysis Algorithm Accounting for Bounded Data Errors

In a statistical pattern recognition context, discriminant analysis is designed to classify, when possible, objects into predefined categories. Because this method requires precise input data, uncertainties cannot be propagated in the classifying process. In real case studies, this could lead to drastic misinterpretations of objects. A new nonparametric algorithm based on interval arithmetic has thus been developed to propagate interval-form data. They consist in calculating interval conditional probability density functions and interval posterior probabilities. Objects are eventually assigned to a subset of classes, consistent with the data and their uncertainties. The classifying model is thus less precise, but more realistic than the standard one, which we prove on a real case study.     

南昌地震台钻孔应变同震响应分析

通过总结2007年5月以来南昌地震台TJ-2钻孔应变仪的同震效应,并与同期中国地震台网(CSN)提供的全球大震目录中的数据进行对比分析,绘出了震级与震中距的对数关系图,得出南昌地震台体应变仪的映震能力的表达式近似为Ms=1.381gD+ 1.1.     

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气压对巴伦台钻孔倾斜的影响特征及机制研究

以巴伦台钻孔倾斜及分量应变辅助观测气压数据为研究对象,运用相关及小波分析研究气压对巴伦台钻孔倾斜的影响特征。结果表明,气压对巴伦台钻孔倾斜影响表现为准线性关系,对NS向的影响大于EW向。气压对NS向影响的显著频段有2 048～8 192、32 768～65 536 min,对EW向影响的显著频段为2 048～8 192 min。探讨了气压对巴伦台钻孔倾斜的影响机制。     

3 D inversion of borehole gravity data using cokriging

Borehole gravity has been used in mineral exPloration recently with the advent of slim-hole gravime-ters. It is logical to Perform inversion to utilize the information in the newly acquired data. The i...     

深部盐岩层绳索取心钻井液技术研究与应用

由于次生应力场的作用以及盐岩易溶于水的特性,深部盐岩层钻进存在岩层蠕动、钻井液易遭受盐钙侵等问题;钻进参数选择不合理易导致盐岩层取心效率低、岩心冲蚀严重。本文以河南省叶舞凹陷ZK3井为例,采用石油钻井与绳索取心相结合的措施,解决了普通固体矿产钻探设备在深部地层取心中效力不足的问题;通过阳离子交换容量测定、矿物组分鉴定、钻井液体系优选及性能测试等试验,确定了针对上部泥岩地层的聚合物钻井液体系,中部含膏泥岩的欠饱和盐水钻井液体系,下部盐岩层取心段的饱和盐水钻井液体系。通过确定合适的钻井液密度与临界环空返速,可以有效控制深部盐岩层蠕变与井壁冲蚀,适度提高排量以成倍提高钻进速度。钻进过程中钻井液性能稳定,体系转换顺利且性能易于调整,为取心任务的顺利完成提供了有力保证。     

白涧铁矿南区复杂地层钻探施工技术

邢台白涧铁矿南区地层岩石破碎、部分地层含角砾、胶结性差、漏失严重,钻探施工中存在掉块卡钻、缩径、坍塌、埋钻及孔内泥浆全部漏失等难题。通过优化钻孔结构、使用新工艺、新方法,合理选择钻进参数,采用绳索取心钻进配合预留技术套管,有效解决了上部煤系地层的坍塌问题;采用反丝套管的方法,极大地减轻了由于地层缩径、掉块引起的套管下不到位、起拔困难等风险;常规型绳索取心钻杆替代套管方法的采用,提高了含角砾、松散地层的穿过速度,减少了钻探工作量的报废,加快了施工进度;特别是高胎体双水口钻头的使用,提高了钻进效率,节约了钻探施工成本,项目得以如期完成。     

周老镇钻孔砾石层重矿物特征及地质意义

利用江汉平原周老镇钻孔的岩心样品,分析研究了钻孔岩心沉积物10层砾石层中填充物的重矿物组分及分布特征。结果显示周老镇钻孔10个砾石层自下而上可以分为3个矿物段。对比3个阶段稳定重矿物、非稳定重矿物的变化特征:阶段Ⅰ、阶段Ⅱ,沉积物主要以近源物质为主,含有少量的远源物质;而阶段Ⅲ,沉积物主要以远源物质为主,含有少量的近源物质。结合周老镇钻孔岩性及钻孔砾石含量和江汉平原第四系岩相剖面特征,判断在阶段Ⅲ,深度112.30～109.05m(1.17～1.12MaB.P.)处,钻孔沉积环境发生了重大改变,江汉平原水系发生重要调整,长江三峡贯通形成。