Identifier

etd-05132013-142333

Degree

Master of Science in Petroleum Engineering (MSPE)

Department

Petroleum Engineering

Document Type

Thesis

Abstract

Safety culture relating to offshore operations has shifted since the Deepwater Horizon blowout and resulting oil spill. This incident has prompted the research of high volume spills during all stages of hydrocarbon exploration and production. This study particularly covers the interactions of wells and offshore networks as they pertain to situations where a release of reservoir fluids to the environment is occurring. Primary concerns of this investigation are stream confluences, leak modeling, and fluid behavior; the first two will be handled with various numerical software packages (OLGA®, CFD, and nodal analyses) while the later will require more rigorous treatment and a combination of these tools with dedicated phase behavior software (such as PVTsim®). This research will combine with risk analysis work being done by others to identify high-priority system failure scenarios. The focus in modeling high-volume leaks thus far has been placed upon reservoir properties, geology and modeling the most uncertain things when this research shows that the most influential variables for particular reservoirs lie within the flow path. When operating offshore, wells connect to subsea manifolds or other junctions to form unforeseen mixtures of crude oils; these combined fluids dictate the outcome of potentially devastating releases offshore. Flow rates through chokes have been modeled using only a few parameters, namely the pressure, choke size and the gas-liquid ratio (GLR). The leak considered herein will choke flow and create a back pressure, which will control how fluids move from the reservoir to wellhead. A properly tuned equation of state can predict the GLR fairly well, but falls short when attempting to combine the GLR of two or more fluids. A correlation is proposed to allow for more accurate leak models when only simple fluid properties are known, such as the heptanes-plus fraction.

Date

2013

Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

Hughes, Richard

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