During the drilling process of extended reach wells,cuttings are easy to accumulate and form a bed at the bottom of the inclined section and horizontal section of the annulus,leading to accidents such as overpressure pumping and sticking,which seriously affect the safety of drilling construction and drilling efficiency.The existing cuttings transport and cuttings bed removal models are all aimed at standard spherical cuttings,which are different from the cuttings returned in real drilling.As a result,the application range of the models is limited and they cannot provide more accurate field guidance.In order to explore the migration law of non-standard spher-ical cuttings in extended reach wells,an empirical model for predicting the thickness of cuttings bed in extended reach wells was pro-posed by combining visual cuttings migration experiments and computational fluid dynamics(CFD)numerical simulation methods.The model was applied in CH1-1-XX well to optimize the drilling parameters under different openings,and good results were achieved.The results show that by using the model to predict the thickness of the cuttings bed and optimizing the drilling process parameters,the maximum cuttings bed thickness during the primary and secondary spuds is 40.6 mm and 33.9 mm,respectively.They are both lower than the safety line of the thickness of the cuttings bed at the same well depth.It indicates the wellbore is highly clean and there is no risk of sticking.The empirical model of cuttings bed thickness prediction established is of great significance to improve the wellbore purification efficiency of extended reach wells and ensure the safe and efficient drilling of extended reach wells.
关键词
大位移井/岩屑床厚度/可视化实验/数值模拟/钻进参数优化
Key words
extended reach well/cuttings bed thickness/visualization experiment/numerical simulation/drilling parameters optimization
维普
万方数据