Research on limit depth of the surface conductor by jetting method in deepwater drilling

Accurate calculating the limit depth of surface conductor has an important significance for the safe and efficient deepwater drilling. According to the stress analysis of the conductor jetting system, the soil parameters and construction parameters affecting the conductor setting depth ware studied. The soil parameter influence factors including soil strength and soil friction resistance, and the construction parameter influence factors including jetting pressure, displacement and verticality. Base on the study of the conductor jetting system in total force balance conditions, a prediction model of conductor limit jetting depth in deepwater were established. An example calculated using the prediction model for the South China Sea actual deep well. The results show that the minimum and maximum depths were practical in actual condition. The actual field application shows that this research has significance help in safety jetting construction design.