Notional Field Development Final Report - EBN

EBN Notional Field Development Plan
5 Summary and Recommendations
EBN and all other operators need to consider a strategy how to develop Shale Gas prospects with a
public acceptance and following all the necessary environmental regulations and laws.. Furthermore, we
strongly recommend EBN to work out a more detailed and comprehensive well plan, i.e. perform
collaborative well planning on both Boxtel and Haaren wells to seek a technical optimal and socially and
environmentally acceptable placement of the wells.
G&G Summary
All available well evaluation data, mudlogs, sample analysis, and petrophysical well logs, support the
conclusion that the Posidonia and Aalburg shales are organic rich source shales. Of the two, the
Posidonia looks to have the best chance of being oil or gas condensate productive because it
demonstrates higher effective porosity. It also exhibits a much lower structural dip than the Aalburg.
That relatively flat dip is required for any kind of potential horizontal well development.
Calculated mechanical properties of the Posidonia support it being a very soft and ductile shale that,
while easy to frac, will make it difficult to establish a lot of effective conductivity by induced fracture
complexity. Proppant conductivity can also be severely compromised by fines embedment in such a soft
shale if subjected to very high differential draw down pressures.
The wild card for enhanced productivity, even though it is a soft shale, appears to be the fact that the
Posidonia overlays a series of numerous faults in a very tectonically active geologic basin. The stress field
generated from these faults immediately below the optimum porosity interval should result in a shale
that is potentially naturally fractured with enough fracture aperture for enhanced fluid delivery and
migration. The existence of the lower faults also will prove to be a geo-hazard if not mapped adequately
prior to horizontal development.
A small number of vertical test, or pilot, wells drilled expressly for evaluation of the Posidonia & Aalburg
shales should be drilled prior to a full-on horizontal development project. A complete modern shale
petrophysical analysis should be performed that would link full core data with modern geochemical well
logs and three dimensional stress measurements for optimum target delineation and optimized fracture
design.
Vertical well(s) and/or test horizontal well(s) should also be test fractured to establish exact pore
pressure, closure stress, and leakoff parameters for optimized fracture design in a development phase.
Many of the techniques discussed in this paper have proven successful in North America.
With this being said, the completion recommendation for EBN is to adopt the third technique – coiledtubing
assisted fracturing and more specifically HydraJetting via coiled-tubing. This method facilitates
stimulating multiple shale intervals with less than half the hydraulic horsepower requirements and a
significantly reduced footprint compared with other currently popular completion methods. This
technology has significant potential because coiled tubing and HWO units are available in Europe. The
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