Calculation method for the vertical bearing capacity of a riser-surface casing composite pile

ABSTRACT

The variable cross-section structure (comprising a riser, surface casing and cementing cement ring) of an oil well associated with an offshore oil platform is similar to that of a steel pipe pile foundation. If a well structure with variable cross-section characteristics can be used to provide bearing capacity, the construction cost of platforms will be reduced. In this paper, the finite element analysis method is used to study the vertical bearing mechanism of composite piles composed of a riser and a surface casing in saturated clay and sand. Based on the theory of spherical cavity expansion, the calculation methods of end resistance and skin friction resistance of composite pile are established. Finally, based on a field test of the bearing capacity of composite piles, the accuracy of the proposed calculation method is verified.

KEYWORDS:

• Riser-surface casing composite pile
• variable cross-section
• end resistance
• rigid soil core
• field test

Acknowledgments

This work was financially supported by the National Science Fund for Distinguished Young Scholars of China (grant NO. 51825904) and the National Science and Technology Major Project from the Ministry of Science and Technology (MOST) of China (grant NO. 2016ZX05058004-005).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was financially supported by the National Science Fund for Distinguished Young Scholars of China (grant number 51825904) and the National Science and Technology Major Project from the Ministry of Science and Technology (MOST) of China (grant number 2016ZX05058004-005).