黏土层钻进存在的问题分析与采取的措施

Problem analysis and contermeasures for drilling in cohesive soil layer

摘要:

在黏土层钻进中易出现缩径、崩塌、黏附卡钻等事故，以及泥包钻头，憋泵现象；且黏性土层具有一定的造浆能力，从而改变了冲洗液的性能参数，影响钻进效率以及岩心采取质量。通过对所钻黏土的力学特性、水化机理，自然造浆对冲洗液性能参数、钻进效率及岩心采取率的不利影响的深入分析，对钻头唇面结构、岩心采取方式、冲洗夜性能参数、钻进工艺等进行了改进和优化，从而提高了黏性土层钻进效率和岩心采取质量，降底了钻进成本。

Abstract:

During drilling in cohesive soil layer， accidents such as shrinkage， collapse， adhesion and drilling rod stuck， are prone to occur， as well as mud-packing drill bits and pump choking-up， and the soil layer has a certain slurry-making ability， which changes the performance parameters of the flushing fluid and affects the drilling efficiency and the quality of the core. Through in-depth analysis of the mechanical properties， hydration mechanism of the soil， the performance parameter’s detrimental influence of slurry-making to flushing fluid， drilling efficiency and core recovery percents， the improvement and optimization to the bit kerf structure， core recovery form， flushing fluid performance parameter and drilling technology and so on are carried out， thereupon improving the drilling efficiency in the soil layer and reducing the drilling cost.