Draugen is a low structural relief oil field with a sandstone reservoir and, at production start-up, a 50m vertical oil column above the free water level. Reservoir quality is excellent with an average porosity of 29% and multi-Darcy permeability.
Draugen started producing light oil in 1993 and had a planned development life of 20 years. After reviewing options for improving recovery, several opportunities are being matured to extend production, aiming to raise the field recovery factor towards 70%. As part of this project, infill drilling to target un-swept attic oil plays an important role.
The infill 2013/14 campaign comprised four wells, drilled and completed in 2013/14 as per plan. The first well was drilled and completed in 2013; the second, third and fourth wells followed in 2014 with demonstrably better well placement results. A fifth well was later added to the sequence, as an accelerated project and based on the previous successful drilling campaign's learning. The well was drilled and completed in 2015, with similar excellent results.
The infill campaign utilized modern deep reading electromagnetic tools in the bottom hole assembly (BHA) in order to achieve the desired well placement. The tools were a key enabler, giving confidence that remaining (thickest un-drained) hydrocarbon resources identified from 4D seismic could be developed: target remaining attic oil columns were thin, that well placement was critical to effectively deliver the well objectives.
Schlumberger ultra deep reading resistivity tools were deployed in the first well during field testing phase, and as the campaign progressed, the Asset team worked closely with Schlumberger to develop well placement and project delivery. During the drilling campaign, the technology was commercialized by Schlumberger.
This paper will discuss the wells landing and geosteering strategy, the results and learnings, as well as the technology evolution throughout the drilling campaign.
