Abstract

It is a reality that oil and gas production is moving to areas where Flow Assurance (FA) risks take a prominent role in the success of operations: arctic, ultra-deepwater conditions imply that the pressure-temperature envelope during operation enlarges, leading to greater chances of solid formation; longer distances to processing facilities difficult remediation operations, in case a blockage occurs. More and more decisions, even in early stages of field life, depend on fluid quality and fluid behavior.

To tackle this issue, Repsol has developed a methodology to account for fluid composition and behavior that allows for an integrated view of Flow Assurance risks that is updated from Exploratory to Operation Phases, from high-uncertainty to low-uncertainty periods of field life.

The presentation will describe several field cases where the methodology is applied, to assure flow assurance constraints are considered in all Phases (Exploratory, Development and Operation); special stress is given to cases where alternatives from conventional tools are required to better represent reality, both in terms of solid formation management, and instabilities associated to multiphase flow.

The objective of this work is to highlight, by means of examples, how critical it is to have an integrated view of fluid properties from Exploratory to Operation Phases, and illustrate how it affects decision taking throughout the life of a field.

Introduction

Flow Assurance (FA), as a discipline in the Oil and Gas industry, refers to the analysis of the factors that may affect the flow of oil and gas from the reservoir to the facilities. Figure 1 shows the main challenges that are covered inside of Flow Assurance. FA topics can be divided into problems associated to Solid Formation and Fluid-Dynamics: the former deals with the reduction of productivity associated to the appearance of solids in the production lines, either originated in the hydrocarbon or in the water that is being co-produced; the latter, with the phenomena related to the presence of several continuous phases (hydrocarbon liquid, hydrocarbon vapor and liquid water) and how their interaction may modify the deliverability of a production network.

Being a quite broad discipline, FA comprises phenomena as different as solids plugging the face of the formation, the difficulties to re-start a pipeline after a long shut-down in cold temperatures or emulsion problems in a separator [1, 2]; it is acknowledged that other companies also include Material Integrity (Corrosion) and Sand Control inside Flow Assurance [3, 4], but these are treated in other areas of Production Engineering inside of our company.

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