Problem analysis and contermeasures for drilling in cohesive soil layer

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.