Modelling of DAS

D. Koutas

Research output: ThesisPd Eng Thesis

Abstract

Monitoring of oil and gas wells is critical for timely identification of production rates and well instability hazards. This work models the pressure fluctuations imposed to a Fibre Optic surveillance installation by single phase liquid flows. The effects of axial flowrates and in-flowrates through casing perforations into the well measured by an Optical Fibre were simulated with the finite element program COMSOL and compared with experimental data collected from the flow-loop of the Shell Centre of Technology in Amsterdam (SCTA). A simple T-joint model was used to simulate the inflow in the well through casing perforations.
The simulation is based on free field aero-acoustic modelling. Physics modeling predicts that aero-acoustic effects can create pressure fluctuations quantitatively significant and potentially retraceable to flow rates from the interrogator data.
The experimental results have shown correlation between signal and flowrates, like the ones observed in oil producers. The trends confirmed by the modelling work are presented in this thesis. The level of agreement between simulation and experiment is strong for low perforation in-flowrates but weakens for higher perforation in-flowrates. This can be attributed to the limitations that cross flows in pipes impose to fluid and aero-acoustic modelling, to the possible existence of unwanted noise to the data and to lack of surveillance device at the perforation.
In addition, experimental runs when completed, might provide statistical data sufficient to confirm flow effects predicted by flow-loop simulations, showing that aero-acoustic effects are not only an eligible part of the signal, but can be also distinguished from other physical effects causing fibre excitation.
Original languageEnglish
Supervisors/Advisors
  • Kreeft, J., External supervisor, External person
  • Kamp, Leon P.J., Supervisor
Award date20 Sep 2018
Place of PublicationEindhoven
Publisher
Publication statusPublished - 20 Sep 2018

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Bibliographical note

PDEng thesis. - Confidential for ever.

Cite this

Koutas, D. (2018). Modelling of DAS. Eindhoven: Technische Universiteit Eindhoven.