Semester of Graduation

Summer 2018


Master of Science in Petroleum Engineering (MSPE)


Craft and Hawkins Petroleum Engineering Department

Document Type



Worst-case-discharge (WCD) calculations are a pre-requisite for any new well to be drilled in the Gulf of Mexico (GoM). Models that were mostly developed for production rates prediction are currently used to calculate the WCD rate. These models were mostly developed for pipe diameters and flow velocities much smaller than those expected during WCD events. Therefore, these models may be miscalculating WCD rates.

This study aims at analyzing one of possible sources of errors in these models: the flow regime maps. The influence of diameter change on flow regimes is discussed. A thorough literature review is carried out for different flow regime maps. These maps are tested against experimental data to define the best flow transition models. A new map with the best transition models is presented. A new flow regime is added to the map, replacing the slug flow: cap-bubble flow. This map is tested with numerical simulation to reproduce experimental and field conditions. In order to do this, a modification to a numerical model is proposed, coupling the new map to the model and the calculation of the pressure gradient when in cap-bubble flow. The results show improvement over the standard map.

Critical flow regime models and its existence during WCD are discussed. It is observed that it will be unlikely for the flow to be in critical conditions during a sub-sea release of deepwater wells, but it is possible that it happens during surface releases.

A series of future works is recommended.



Committee Chair

Waltrich, Paulo J.