Deepwater Gas Kick Simulation

Important gas and light oil reserves have recently been found in the Tupi field of Santos Basin, Brazil. The Tupi is formed by subsalt hydrocarbon reservoirs 6000 to 7000 m deep, with water depths up to 3000 m, subjected to high pressure and high temperature bottomhole conditions. The investigation of well control aspects during exploratory and development drilling in that field requires kick simulators that can handle the pressure and temperature range encountered in deep and ultra deepwater scenarios. Safety issues associated with well control situations demand precise predictions of wellbore pressures and liquid/gas volumes as well as flow rates at the surface. The possibility of blowout occurrence needs to be mitigated in order to avoid human casualties, financial losses (production stop and equipment losses) and environmental damage. Several kick simulators have been developed during the last four decades in order to address well control problems during the drilling operation. The simulators have an important mission that involve: i) helping the drilling engineer to make decisions during well control procedures and kick situations, ii) personnel training and certification and iii) better understanding and interpretation of field observations. The evolution of the codes has been driven by the increasing challenges in exploration and development of the remaining hydrocarbon reserves. Increasing complexity of well geometry (diameters and trajectory), well location (land and offshore) and bottomhole conditions (increasing pressure and temperature severity with depth) has required more precise two-phase flow models and more representative rheological as well as compositional models. This work presents the mathematical modeling of a proposed gas kick simulator, the comparison between simulated and measured results for a test well located in Brazil, and a sensitivity analysis regarding the effect of water depth in well control parameters. © 2009 Elsevier B.V. All rights reserved.671-21322Beggs, H.D., Brill, J.P., A study of two-phase flow in inclined pipes (1973) J. Petrol. Technol., pp. 607-617Bourgoyne Jr., A.T., Chenevert, M.E., Milheim, K.K., Young Jr., F.S., (1986) Applied Drilling Engineering, , SPE textbook seriesFjelde, K.K., (1995) Numerical Methods for Simulating a Kick, , M.Sc. Thesis, University of Bergen, NorwayLage, A.C.V.M., (2000) Two-phase Flow Models and Experiments for Low-Head and Underbalanced Drilling, , Ph.D. Dissertation, Stavanger University College, NorwayLage, A.C.V.M., Time, R.W., Mechanistic Model for Upward Two-Phase Flow in Annuli (2000) SPE Annual Technical Conference and Exhibition, , Paper SPE 63127, Dallas, Texas, Oct. 1-4Leblanc, J.L., Lewis, R.L., A mathematical model of a gas kick (1968) J. Petrol. Technol., pp. 888-898Marques, M., (2004) Experimental Procedure and Validation of Special Well Control Situations, , M.Sc. Thesis in Portuguese, Federal University of Rio de Janeiro, BrazilNickens, H.V., (1987) SPE Drilling Engineering, pp. 158-173Nunes, J.O.L., Cordovil, A.G.D.P., Ribeiro, P.R., Well control in deepwaters: a review (2002) II National Cong. of Mech. Eng., João Pessoa, Paraíba, Brazil, Aug. 12-16Santos, O.L.A., Well control operations in horizontal wells (1991) SPE Drilling Engineering, pp. 111-117Yarborough, L., Hall, K.R., How to solve equation of state for Z-factors (1974) Oil Gas J., p. 8