Finite Element Modelling of Setup Effect during Conductor Casing Instal- lation with Coupled Eulerian-Lagrangian Method

Resumo

The first tubular section installed in drilling operations is the conductor casing. Usually run by hammering
or driving, the casing is responsible for guaranteeing well stability, isolating fluids from formation, and providing

areas for installing equipment such as wellhead and christmas tree assembly. By inspecting soil behaviour dur-
ing the installation process, it is notable that pore pressure disturbance triggers what is called the Setup Effect,

a phenomenon where conductor load capacity increases over time due to pore-water pressure dissipation. This
study applies the Finite Element Method (FEM) to model a Conductor Casing installation employing Coupled

Eulerian-Lagrangian (CEL) technique to evaluate the setup effect. CEL technique is well suited to large deforma-
tions problems; however, pore pressure measurement is not supported in Abaqus/Explicit; thus, a Vectorized User

Material (VUMAT) subroutine was implemented to take into account that effect. Mohr-Coulomb model represents
soil’s constitutive behaviour, and the results are compared with data obtained from Brazilian cases in soft clay
soil. This kind of study helps to increase the safety of drilling operations and the structural well integrity analysis
since pore pressure estimation is necessary to determine the ideal weight of the drilling fluid, preventing fracture,
formation damage, and fluid loss, ensuring the borehole stability during drilling.