Multi-Dimensional Selection Method for Well Construction in Shallow Formations of Deepwater

Due to the characteristics of variable marine environment, complex geological conditions, high operational risks, and high day rates of deepwater drilling operations, it is difficult to choose suitable method for well construction in shallow formation in deepwater. Taking into account all relevant factors, including seabed soil strength, well construction quality, operation efficiency, cost efficiency, drilling safety risk control, and other factors, the adaptability of different well construction methods were analyzed based on the field operation engineering data. A single-dimensional adaptability classification mechanism was established, and a multi-dimensional selection method for well construction in shallow formations of deepwater was formed through quantitative visualization using radar charts. The results show that in the South China Sea with a water depth of 500−1500 meters, the jetting method is the optimal method for well construction in shallow formation during single well operation, and the operation efficiency can be improved by more than 50% compared to the drilling method. This method has achieved good application results in dozens of deepwater wells in the South China Sea, which provides a quantitative evaluation approach for the selection of well construction methods in deepwater complex formations.