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Geofysikk
Master project

Updating of geological surfaces during drilling by map migration

This master's project is available from the intake of August 2019

Project description

The drill bit emits seismic waves that can be used for geosteering in real time. By analysing these data, we can reposition the drill bit, as well as detecting risks (e.g faults and karst) and geological targets ahead of the bit. The data can be acquired on permanent reservoir monitoring (PRM) systems or on smaller ocean-bottom cables which are deployed during drilling. The drill bit emits a continuous signal that can be deconvolved in a similar manner as in vibroseis processing onshore, and the dataset coming out of the process is comparable to VSP data. One of the purposes of this dataset will be to update the velocity model during drilling. Map migration of interpreted geological surfaces using the new velocity information can improve the geological interpretation ahead of the drill bit. This is information that will be of great value for the operator during drilling.

The goal of the work is to develop a workflow where map migration with ray-based methods can be used to update geological surfaces in real time. The input will be geological interpretations and velocities from existing seismic data and updated velocity information from inversion of drill-bit seismic waves.

The work consists of the following key elements: 1) Generate model data 2) Develop the workflow and test on modelled data 3) Try the workflow on real data 4) Use of machine learning in selected steps of the workflow.

Proposed course plan during the master's degree (60 ECTS)

GEOV219 – Computational Methods in Solid Earth Physics (vår)
GEOV272 – Seismisk tolkning (høst)
GEOV277 – Signalanalyse og inversjon i geovitenskap (høst)
GEOV375 – Avansert anvendt seismisk analyse (vår)
AG-335 – Arctic Seismic Exploration (vår)

Prerequisites

BSc. in geophysics, mathematical specialization

External data

OCTIO will seek to make a real dataset available for the project.

Analytical work

The student will get access to software for seismic modelling, processing and interpretation.