Multiple wellheads for offshore operations converge on a platform. Conductor is in a dense layout and the spacing is gradually reduced. The soil disturbance stress fields of pile driving are superimposed on each other, resulting in pile group effect, which has a vital effect on the ultimate bearing capacity of conductor. In this paper, the ultimate bearing capacity of the conductor under the condition of soil squeezing effect and pile group effect is studied by numerical simulation. It is concluded that the soil mass in the range of 3.26 times the conductor diameter from the center of the pipe will be disturbed greatly. With the pile group layout structure, the pile group effect coefficient decreases gradually as the pile spacing expands from 2 times pile diameter to 5 times pile diameter, and it is found that the bearing capacity of corner pile is larger than side pile and side pile is larger than center pile.
For the exploration and development of shallow sea areas, conductor is connected to the offshore platform and the shallow seabed, which is the bearing structure of the offshore platform. If the bearing capacity of the conductor is insufficient, the conductor will not be able to support the wellhead and wellhead equipment, which will lead to wellhead sinking and even wellbore scrapping.
During the installation of the conductor, it will be subjected to the extrusion effect and pile group effect, which will have a significant impact on the ultimate bearing capacity of the conductor. Therefore, it is necessary to carry out the research on the ultimate bearing capacity of the conductor under the pile group effect, so as to avoid the risk of offshore construction operations, so as to improve the safety and practicability of related work.
Many scholars have carried out lots of studies on this through theoretical and experimental analysis, but have not carried out numerical simulations of the pile effect.
