共查询到19条相似文献，搜索用时 875 毫秒
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进行了桶形基础负压沉贯的室内试验、中间试验和现场沉贯.对负压沉贯的机理进行了初步分析,结合CB20B桶形基础计量平台的现场测试数据,研究了负压对桶形基础沉贯阻力的影响及对土壤特性的影响,同时对负压、沉贯深度、沉贯速度之间的关系进行了总结.在此基础上,提出了改进的计算沉贯阻力的经验公式. 相似文献
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进行了桶形基础负压沉贯的室内试验、中间试验和现场沉贯。对负压沉贯的机理进行了初步分析,结合ＣＢ２０Ｂ桶形基础计量平台的现场测试数据,研究了负压对桶形基础沉贯阻力的影响及土壤特性的影响,同时对负压、沉南深度、沉贯速度之间的关系进行了总结。在此基础上,提出了改进的计算沉贯阻力的经验公式。 相似文献
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海上现场试验对于桶形基础平台的沉贯安装十分重要.论述了桶形基础平台原型单桶模型在海上现场负压沉贯的方案、方法和过程,得出了试验结论,并将试验成果成功应用于CB20B采油工艺平台的海上沉贯安装,对浅水区桶形基础平台的现场施工具有指导意义. 相似文献
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海上现场试验对于桶形基础平台的沉贯安装十分重要。论述了桶形基础平台原型单桶模型在海上现场负压沉贯的方案、方法和过程,得出了试验结论,并将试验成果成功应用于ＣＢ２０Ｂ采油工艺平台的海上沉贯安装,对浅水区桶形基础平台的现场施工具有指导意义。 相似文献
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海上平台桶形基础模型负压沉贯试验数据处理与分析 总被引：1，自引：0，他引：1
海上平台桶形基础是一种新型海洋石油开发技术,其特点是利用负压将桶形基础贯入海底。本文介绍了单模型和四桶模型平台负压沉贯试验数据处理方法,对负压作用下桶形基础的沉贯过程进行了分析,探索出桶形基础平台机理现场条件下的沉贯方法。 相似文献
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海上平台桶形基础模型压力压贯与负压沉贯试验研究 总被引：1，自引：0，他引：1
介绍了海上平台桶形基础模型（模型桶）压力压贯和负压沉贯的试验概况,对比分析了两者贯入力的巨大差异和产生的原因,给出了模型桶压力压贯中贯入深度与压力的关系,负压没贯负压与贯入深度,抽吸泵流量,基土渗流量,桶内土塞隆起之间的关系,试验结果表明,负压沉贯可以大大降低以砂质粉土为基土的土抗力,为在胜利油田类似基土海域海上平台应用桶形基础提供了试验依据,为海上现场导管架桶形基础平台的安装就位施工和控制提供了 相似文献
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正压冲固平台是一种采用短桩加固基础的新型海洋采油平台,对于这种新型的平台结构,在结构分析和构件强度校核中必须考虑其有限元模型的基础边界条件处理问题。本文提出了正压冲固平台有限元计算模型中基础边界条件的一种简化方法,将两个水平方向的扭转自由度简化为扭转弹簧边界元,其余自由度简化为固定约束。通过计算分析得到了不同的边界约束刚度系数的取值对平台总体位移和强度校核应力的影响及变化趋势。结论是,平台结构对约束刚度系数K的反应在10^4～10^4之间时比较明显,对K的敏感度最为强烈：在此范围之外,平台反应分别接近于简支约束情况和刚性约束情况。尤其对于接近约束边界的单元,其应力变化最敏感。 相似文献
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海洋深水区域日益成为海洋油气勘探开发的热点,但海洋深水地层因其特殊的沉积环境,致使深水钻井面临不稳定的海床、地层破裂压力低及海底低温等诸多的挑战,喷射导管技术是解决深水浅层所面临挑战的技术之一.该技术采用在导管内下入喷射动力钻具的方式,依靠导管串自身重力边钻进边下入导管,喷射到位后利用地层的黏附力和摩擦力稳固住导管,起出送入工具和管内钻具,完成导管的安装,避免因水泥浆密度过大而压破地层,也可避免由于深水低温等因素影响固井质量.通过对导管的受力分析,提出了导管的下深及导管串组成结构,同时也研究了导管在喷射安置过程中如何优选喷射钻进参数及采取的技术措施,确保导管喷射安置到预定位置,为海洋深水井导管设计与喷射安置导管提供了很好的参考与借鉴. 相似文献
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ABSTRACTThe purpose of this paper is to develop a method for calculating side friction resistance during the jetting process to improve drilling efficiency. Side friction dynamics in length of time was determined by means of dynamic force analysis of the conductor during the jetting process by experiment, and the real-time calculation model of side friction between the formation and conductor was developed. In particular, 3-1/2″, 5-1/2″, and 9-5/8″ conductors were used to simulate actual field operation. The calculated values match well with the true values. Simulation experiments were performed in the central fishing harbor of Bohai Sea, Tianjin Province, China. 相似文献
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从高压水射流技术在水下工程中应用及高压水射流的作用效应和伤害特征着手,分析影响水下高压水射流作业安全的因素,总结各国制订高压水射流作业的安全标准规程现状,提出制订我国水下高压水射流作业安全规程若干认识和设想。 相似文献
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The jack-up unit may suffer difficult extraction from soft clay attributed to the large embedment and suction. To ease spudcan extraction, the jetting technique is extensively adopted. The jetting effect on spudcan extraction is investigated with a series of model tests. Firstly, the effectiveness of top jetting is investigated, and it is found that the top jetting is not effective in reducing extraction resistance. Secondly, the efficiency of different jetting procedures are studied. It is revealed that jetting prior to extraction reduces the suction by increasing the excess pore pressure at spudcan base. And the jetting after extraction begins reduces the suction by filling the gap formed under the spudcan with jetting water and eliminating cavitation. Finally, tests with different jetting times, jetting rates, jetting pressures, and jetting nozzle locations and numbers are conducted. It is found that the effect of jetting time converges as it increases. The flow rate of jetting prior to extraction has little effect on jetting efficiency, whereas the flow rate of jetting after the extraction begins has significant influences on the jetting efficiency. Jetting pressure also has great effect on jetting efficiency, and converges as it increases. The closer the nozzles are located to the spudcan edge, the sooner the post-peak extraction resistance decreases. And the jetting efficiency increases with the nozzle number. The findings from the experimental studies can serve as a reference for future studies on the operation and optimization design of a jack-up jetting system. 相似文献
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桶形基础沉贯室内模型试验研究 总被引：3，自引：0，他引：3
桶形基础采用负压沉贯法施工,其贯入阻力与压桩,打桩等施工方法显著不同。本文介绍了在粉土和粉质粘土地层中的一组模型试验情况,认为负压法施工可显著降低粉土的抗贯阻力,但在粉质粘土中减阻效果不明显。 相似文献
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Mobile jack-up drilling rigs are deployed at many locations during their service life. This necessitates retrieval of the platform’s legs and spudcan footings before the rig move. In soft soils, where the spudcans embed deeply, the extraction process can be difficult, time consuming and therefore costly. Water jetting systems, devised to ease spudcan extraction, are a common feature on modern jack-up units. However, their effectiveness in reducing the pull-out load required is questioned by the offshore industry. To investigate their efficiency, centrifuge experiments of a reduced scale spudcan model with jets have been performed at the University of Western Australia. The footing was extracted from penetrations of up to 1.5 diameters in normally consolidated clay. Similar to spudcan extraction in the field, these were carried out under load control, applying a constant extraction force. Both influences of pull-out load magnitude and jetting flow rate were investigated. The study demonstrates that jetting is efficient in facilitating spudcan extraction, as it reduces the required uplift load. Practical guidance is provided in applying the results to field conditions. 相似文献
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The mechanical properties of shallow soils in deep water play an important role in drilling design and construction as well as later oil and gas development. Since it is difficult to collect soil samples from layers deeper than 10 m below the sea floor, the acquisition of shallow soil mechanics, based on the variation of drilling parameters in the deep-water drilling process, is not only economical but also reliable. In this article, we analyze the variation of subsea soil properties based on the variation of deep-water jet-drilling construction parameters, calculate the lateral friction resistance of conductor by use of weight-on-bit (WOB) and displacement parameters in the jetting process, and determine the drilled formation’s shear strength and internal friction angle in consideration of restored friction resistance. To verify the accuracy of the prediction-while-drilling model on seabed shallow soil mechanics, indoor unit and field simulation experiments were separately conducted. Moreover, the calculations from field application examples indicate that the prediction-while-drilling of deep-water seabed shallow soil mechanics achieves high conformity with the local practice results, which also indicates that this method could effectively guide field construction operations. 相似文献