Pressure calculations and kick detection with synthetic-based muds in a riserless drilling configuration

This paper presents an analysis of the temperature and dynamic pressure behavior occuring in a Riserless Drilling (RD) configuration, deepwater well when circulating a synthetic-based mud (SBM). Also discussed are some aspects of kick detection in this new configuration related to the gas solubility of SBM's. A numerical model has been developed to simulate the mud flow through the Open-Seawater-Drillstring-and-Return-Line configuration system. The simulator is based on the numerical solution for the system of flow equations using finite-difference approximations. The model accounts for the pressure and temperature dependence of mud viscosity and mud density. Through a sensitivity analysis, the effects of pertinent parameters - specially the circulation rate - on the pressures generated in the system are examined. Also, an EOS model was calibrated with PVT data to investigate the swelling of the synthetic-based mud containing dissolved gas. An equation for the solubility of methane in synthetic oil and a procedure for calculating the pit-gain with increasing time are presented.

Pressure calculations and kick detection with synthetic-based muds in a riserless drilling configuration Academic Article