Technical Library

  • System derisks exploration in northwest Europe

    Author: Per Helge Semb
    E&P Daily News - 15 June 2017

    View summary

    Multiclient dataset uses advanced processing techniques to better image the region.

  • Efficient broadband LS-WEM

    Author: Shaoping Lu, Xiang Li, Alejandro Valenciano, Nizar Chemingui, Cheng Cheng
    E&P Daily News - 14 June 2017

    View summary

    A new methodology for LS-WEM is much less compute-intense.

  • New workflow quantifies uncertainties associated with model building

    Author: Tony Bell, Lorenzo Russo, Tony Martin, Dennis Van Der Burg
    E&P Daily News - 14 June 2017

    View summary

    Analysis tool provides interpreters with information about the reliability of seismic images

  • A bigger picture view of separated wavefields and marine broadband seismic

    Author: Andrew Long
    First Break - 1 June 2017

    View summary

    Andrew Long considers present and future opportunities using separated wavefield data to illuminate, resolve, characterize and monitor reservoir properties and production in various marine settings.

  • The Great Australian Bight – from AVO prospectivity screening to potentially drillable targets in one of the world’s remaining untapped basins

    Author: Dushan Rajeswaran, Marcin Przywara
    AAPEA Journal - 29 May 2017

    View summary

    The Ceduna Sub-basin in Australia’s southern margin offers an untapped opportunity for significant petroleum resource as part of the global exploration portfolio. Analogous to the prolific Niger delta in both size and structural style,
    this highly-extensional province contains up to 15 km of largely untested post-rift sediments including two widespread Late Cretaceous deltas linked to world-class oil-prone marine Cretaceous source rocks.


    Regional interpretation of legacy 2D seismic across the Bight Basin brings the sheer scale and structural complexity of this giant Cretaceous depocentre into perspective, but it is only through the detailed analysis of 8001 km2 of dual-sensor
    towed streamer 3D seismic that its true potential can be quantified. Rigorous phase and amplitude AVO QC of the pre-stack information, coupled with optimised velocity models fed into the depth migration sequence, have ensured amplitude fidelity and phase stability across all offset ranges. This has enabled a systematic and robust exploration workflow of AVO analysis and pre-stack inversion despite limited well data. Numerous dual-sensor case studies have nevertheless demonstrated these Relative Acoustic Impedance and Vp/Vs volumes to be reliably robust for prospect de-risking because of the extended low frequency bandwidth.

    Frontier screening supported by a partially-automated high-resolution stratigraphic framework has led to the identification of numerous prospects at multiple stratigraphic levels across the survey area. This includes isolation of laterally extensive and vertically amalgamated fan-like structures within the shallow Hammerhead delta using horizon-constrained high definition spectral decomposition, and the extraction of potential AVO anomalies within the deeper structurally-controlled White Pointer sands draped across large gravity-driven listric growth faults.

  • Delivering increased CSEM data density

    Author: Joshua May
    Oilfield Technology - 1 May 2017

    View summary

    Joshua May details a new approach to the acquisition and integration of complementary data which is designed to provide improved drilling sucess rates.

  • Utilizing a novel quantitative interpretation workflow to derisk shallow hydrocarbon prospects — a Barents Sea case study

    Author: Laurent Olivier Feuilleaubois, Valerie Charoing, Andrea Maioli, Cyrille Reiser
    First Break - 1 March 2017

    View summary

    The authors demonstrate that combining separated wavefield imaging with high-resolution velocity computations improves the pre-stack amplitude analysis of shallow water hydrocarbon targets in the Barents Sea.

     

  • New plays on the Greater East Shetland Platform (UKCS Quadrants 3, 8-9, 14-16) – part 2: newly reported Permo-Triassic intra-platform basins and their influence on the Devonian-Paleogene prospectivity of the area

    Author: Stefano Patruno, William Reid
    First Break - 1 January 2017

    View summary

    Despite significant discoveries within Palaeogene-age reservoirs (e.g., Mariner) the East Shetland Platform (ESP) is underexplored, with only ten wells per 1000 km2. Mesozoic units are thin or absent whilst Paleozoic reflectors resemble acoustic basement on legacy seismic. Recent 3D dual-sensor broadband surveys (GeoStreamer) covering 17,200 km2 over parts of Quadrants 3, 8-9, 14-16 have allowed for clearer imaging. Here, this dataset is interpreted, leading to new insights into this large frontier region.

    The ESP petroleum system comprises multiple proven reservoir and source intervals, with viable play fairways. Up to four regional unconformities are interpreted, merging into fewer erosional surfaces on persistent highs. Elsewhere
    on the ESP, predominantly subsiding Permo-Triassic depocentres contain a nearly continuous Paleozoic-Mesozoic succession. The most prominent of these, to the south and south-west of the Beryl Embayment, is here referred to as the 'Crawford-Skipper Basin'.

    Existing hydrocarbon discoveries on the ESP are in the vicinities (<7 km) of intra-platform Permo-Triassic basin margins.Exploration close to such basins is inherently less risky due to possible positive influences of deep-seated structures on the petroleum system. These include: (1) formation of Meso-Cenozoic closures; (2) Devonian source maturity and presence of simple fault-related migration pathways; (3) viability of sub-Cretaceous reservoir-trap-seal configurations.

  • FWI for model updates in large-contrast media

    Author: Sverre Brandsberg-Dahl, Nizar Chemingui, Alejandro Valenciano, Jaime Ramos-Martinez, Lingyun Qiu
    The Leading Edge - 1 January 2017

    View summary

    We describe a new solution for recovering the long-wavelength features of a velocity model in gradient-based full-waveform inversion (FWI). The method uses reflected and transmitted wave modes to recover high-resolution velocity models. The new FWI gradient enables reliable velocity updates deeper than the maximum penetration depth of diving waves and reduces the FWIdependency on recording ultralong offsets. We also discuss a new FWI regularization scheme that overcomes the limitations of the inversion in the presence of high-contrast geobodies and cycle skipping. The solution utilizes a priori information about the earth model in the regularization as an extra term in the objective function. The implementation makes use of the split Bregman method, making it efficient and accurate. Results from applying the new FWI gradient to field data show that we can combine both transmitted and reflected energy in a global FWI scheme to obtain high-resolution velocity models without imprint of the reflectivity on the velocity updates. We illustrate the new regularization method's potential on the BP 2004 velocity benchmark model where our regularized FWI solution is capable of using a simple starting velocity model to deliver a high-quality reconstruction of salt bodies.

  • New plays on the Greater East Shetland Platform (UKCS Quadrants 3, 8-9, 14-16) – part 1: Regional setting and a working petroleum system

    Author: Stefano Patruno, William Reid
    First Break - 1 December 2016

    View summary

    Despite significant discoveries within Palaeogene-age reservoirs (e.g., Mariner) the East Shetland Platform (ESP) is underexplored, with only ten wells per 1000 km2. Mesozoic units are thin or absent whilst Paleozoic reflectors resemble acoustic basement on legacy seismic. Recent 3D dual-sensor broadband surveys (GeoStreamer) covering 17,200 km2 over parts of Quadrants 3, 8-9, 14-16 have allowed for clearer imaging. Here, this dataset is interpreted, leading to new insights into this large frontier region.

    The ESP petroleum system comprises multiple proven reservoir and source intervals, with viable play fairways. Up to four regional unconformities are interpreted, merging into fewer erosional surfaces on persistent highs. Elsewhere on the ESP, predominantly subsiding Permo-Triassic depocentres contain a nearly continuous Paleozoic-Mesozoic succession.The most prominent of these, to the south and south-west of the Beryl Embayment, is here referred to as the 'Crawford-Skipper Basin'.

    Existing hydrocarbon discoveries on the ESP are in the vicinities (<7 km) of intra-platform Permo-Triassic basin margins.Exploration close to such basins is inherently less risky due to possible positive influences of deep-seated structures on the petroleum system. These include: (1) formation of Meso-Cenozoic closures; (2) Devonian source maturity and presence of simple fault-related migration pathways; (3) viability of sub-Cretaceous reservoir-trap-seal configurations.