DATA LIBRARY

BJORNOYA BASIN FS
Survey Information

Program time frame: 2016

Bjornoya Basin FS line was aimed at testing GWL FloatSeis™ technology capabilities in the framework of a long-offset 2D multi-client survey in the Barents Sea.  The 113 km line acquired with help of GWL FloatSeis™ super-long offset recording acquisition technique is notable from previous GWL FloatSeis™ projects for dense free-float recording units spacing helped to obtain well-resolved Full-Waveform Inversion (FWI) velocity model better suitable for migration and time to depth conversion.

FloatSeis™ line was acquired in the framework of a long offset 2D multi-client survey in the Barents Sea. The survey objective was to acquire long-offset profiles that image large scale deep seated crustal structures beneath the Norwegian Barents Sea. The survey was conducted with a towed slant 12 km seismic streamer and an air gun array with a total volume up to 6100 cu. inch. The geological section is complicated by rift-related structures, multiple faults and fractured zones, presence of salt formations and erosional surfaces. All these factors are detrimental for clear deep depth seismic imaging, even though the slant streamer data acquisition technology was applied. Long offset (25km+) FloatSeis™ FWI velocity model is insensitive to factors crucial for CDP velocity analysis, as a result it correlated better with available VSP data, proving being closer to the true velocity distribution.  FloatSeis™ FWI velocity model helped to suppress random noise, better focus reflections, eliminate multiples (SRME and WEMA were not able to suppress) and increase quality of Pre-stack Depth Migration in terms of improved resolution and more precise time to depth conversion (results were compared with available well tops data).

2D CDP seismic streamer acquisition parameters:

  • Source — 6100 cu. inch; 2000 psi

  • Streamer — 12,000m

  • Recording — 37,5m pop, 16 sec records

GWL FloatSeis™ super-long offset acquisition parameters:

  • Recording units interval – 3,5 km

  • Recorded offsets – 25 km+

  • Continuous recording

Geological Objectives

The objectives of the project were as follows:

  • Deep investigation of the crystalline basement

  • Reveal the major elements of the Earth crust architecture

  • Cross wells and potential fields anomalies

  • Cross Loppa High-Bjornoyrenna Fault Complex - Fingerdjupet Sub-Basin-Bjornoya Basin - Stappen High suture zones

  • Provide high quality deep depth imaged exploration seismic data integrated with gravity and magnetic data

  • Provide well-resolved geologically interpretable FWI velocity model

Deliverables

Deliverables include PSTM, PSDM, FloatSeis™ FWI velocity model, marine gravity and magnetic data.

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