An Analysis of the Factors Affecting the Load-Bearing Capacity of Deep Water Drilling Conductor

Driving depth, mechanical performance and load characteristics of deep water drilling conductor are the main factors affecting the load-bearing capacity. It is important to keep in mind that capacity directly affects connection stability between the conductor and wellhead. Currently, the size and driving depth of conductor are mainly based on experiences and they lack a theoretical basis. By establishing a mechanical model in which seabed stratum properties, longitudinal and lateral loads, and mechanical performance of conductor are comprehensively considered, the lateral displacement and stress distribution laws of the lower conductor section under various load are analyzed, and it is demonstrated that lateral load at wellhead is the main factor controlling the lateral displacement of conductor, while the axial load does not significantly affect the lateral displacement of the conductor. As the driving depth of conductor increases, the lateral displacement of the conductor decreases gradually, while the stress increases firstly and then decreases. The inflection point of change for the displacement and stress is around 10m at the conductor driving depth. The mechanical performance of the foundation exerts an obvious influence on the displacement and stress distribution of conductor. The research results are of theoretical and engineering significance for the optimization of mechanical parameters, structural size and driving depth of deepwater conductor under different working conditions, such as seawater fluctuation and seabed mechanical performance.