GEOLOGY

HYDROGEOLOGICAL SYSTEM ANALYSIS

GGE geological competence spans the entire range from greenfield exploration aquifer development all the way to fresh water reservoir scale production:

  • Basin and hydrocarbon habitat analysis (basin, sub-basin scale)
  • Play characterization (reservoir, water charge, seals)
  • Litho- and chronostratigraphic correlations
  • Depositional systems modelling
  • Lead / prospect generation and portfolio ranking
  • Reservoir characterization
  • Structural (trapping) integrity & fault seal analysis (Allen diagram)
  • State-of-the-art seismic interpretation and attributes analysis
  • Static model building (petrel a.o.)
  • Prospect maturation to well proposal level
  • Coherent and systematic risk identification and quantification
  • Field work, core descriptions, surface sampling , lab analysis
  • Competitive bid round support

SeDimentoLogy anD DiageneSiS of deep aquifers

With regard to reservoir characterisation, GGE focuses on the following determining aspects :

  • Chrono-, bio- and lithostratigraphical framework
  • Facies distribution, depositional setting and palaeogeography
  • Gross and Net reservoir definition, distribution and thickness maps
  • Lateral reservoir heterogeneities detection and prediction
  • Porosity-Permeability, and Porosity-Depth, Overburden and Porosity
  • Free vs. Bound Water
  • Relationships (trends) for reservoir properties extrapolation
  • Dual Porosity system evaluation (fractured reservoirs)
  • Petrographic analysis on cores, cuttings and thin-sections (see sedimentological studies)

SeDimentoLogy anD DiageneSiS

Laboratory scale sedimentological studies are performed on clastic  and carbonate aquifers. These can include but are not limited to petrographic (thin section) descriptions, microfacies and depositional analysis, pore type geometry descriptions, diagenetic overprint assessments and paragenetic sequence classifications.

Sedimentological services can be carried out on sample material obtained from cores, plugs, sidewall cores and cuttings. Facies types (grain components, porosity and cement types) are described qualitatively or quantitatively.

GGE also provides more specific analytical services including :

  • Cathodoluminescence
  • Scanning electronic microscopy (sem)
  • QEMSCA
  • Fluid inclusion analysis
  • X-ray diffraction analysis/ X-ray fluorescence
  • Isotopic geochemistry : Rubidium-Strontium / Carbon-Oxygen

Special microscopy, mineralogical and isotope analyses can be also carried out to help to better resolve complex reservoir settings, depositional aspects and multi-phased diagenetic alterations and overprints (e.g. dolomite characterization and brine mineralization). Studies are always delivered in a well structured framework allowing quick overview for further decision taking as well as detailed references for planning further work , integration and simulation.

Sequential stratigraphy and biostratigraphy

Resolving relevant facets of reservoir stratigraphy is essential to appreciate its overall geological embedment and architecture. This leads to understanding which factors control significant lateral and vertical variability which in turn is key to build meaningful fluid flow and productivity simulations.

Relevant elements that embrace outcrop analogues, seismostratigraphic interpretation (facies analysis), core observations, any evidence from cuttings, thin-sections and logs and other sources. All such information is integrated into coherent quantitative models that allow to considerably reduce risks and uncertainties associated with origin, geometry, orientation and extent and variability of the rock unit in question.

GGE provides high resolution biostratigraphic analysis, an essential tool to resolve critical stratigraphic uncertainties (formation boundaries, stratigraphic correlation). Analytical tools embrace among other micropaleontology of benthic and planktonic foraminifera (both on thin-sections and on washed samples), ostracods, conodonts and radiolarian as well as palynology and cover Palaeozoic, Mesozoic and Cenozoic eras.

Basin modelling

Understanding the interplay and the dependencies water charge expulsion, migration timing from surface and trap formation and concluding on risks and uncertainties on the potential of finding fresh water accumulations are basin modelling key objectives.

GGE recommends 1D/2D basin modelling work where it can materially contribute to mitigate exploration risk, be it on extending proven prospective fairways beyond known geographical limits or be it on developing new plays.

At more a regional scale, 3D modelling applying state-of-the-art software conducted by experienced experts may be the approach of choice if economically supported.

MAPPING & STRUCTURAL ANALYSIS AND IDENTIFICATION OF HIGH FLOW RATE AREAS

PORTFOLIO MATURATION AND MANAGEMENT

WELL PROPOSALS