Objective
Project aims to validate a method to predict fracture/fissure development in subsurface. The process involves innovative techniques developed during the R &D phase and integration of methodologies.
The validation will be the development of a proven tight gas reservoir with use of specialist drilling techniques refined from those recently developed in the public domain. Innovative aspects of the project are:
- Autocorrelation function applied to the fracture analysis of remote sensing data
- Gaussian Curvature Analysis and developable surfaces concept applied to the prediction of areas with stronger fracturing
- Integration of methodologies including remote sensing, outcrop studies, seismic, well data, and water well productivity and video analysis of fractures
- Multi-lateral well (vertical pilot well and two drain holes) and underbalanced drilling (using a rotating BOP) will be the drilling techniques that will be refined to develop this tight gas reservoir.L%
With regards to the different items considered in the Project as submitted to the Commission, the Project itself could be considered to be almost completed covering the following aspects :
Phase 1 : Design
- geoscience studies
- lease, rentals, etc
- underbalance drilling study
Phase 2 : Manufacture
- site construction
- drill vertical hole
- PVT and core analysis
- intermediate internal well report.
Phase 3 : Assembly
- drill two laterals underbalanced
Phase 4 : Commissioning
- complete and test well.
In spite of the results obtained with the underbalanced drilling method which is not suitable for drilling this type of unit, the remaining items currently in progress are, all of them out of the project scope:
- long term production test design and equipment acquisition
- additional G&G studies
- project evaluation
- monitoring of the Long Term Production Test
- project evaluation regarding further drilling activities.
The project seeks the demonstration of a new exploration approach designed to explore and develop fractured tight reservoirs, with the aid of new and more efficient drilling technologies.
The developed exploration approach has been fulfilled in the R&D phase of the project. The innovative exploration method includes:
- Autocorrelation Function (ACF) applied to fracture anisotropy analysis. It allows to predict areas of enhanced fracture porosity and to plan optimum direction of drilling in multilateral deviated wells in order to achieve higher production rates from a single well.
- Gaussian Curvature Analysis (GCA) and Developable Surfaces Concept applied to the prediction of fracture intensity and occurrence in subsurface. Is based in the geometrical/mathematical analysis of subsurface structural contours and predicts areas in a folded region where fracture intensity is higher. Thus optimum well location can be achieved. The exploration phase has also been aided by the integration of different disciplines involving outcrop and subsurface data in a truly integrated fashion. These have included: Landsat, aerophotograms, ACF, field studies of fracturing, outcrop sedimentological analysis of reservoir equivalents, seismic reprocessing to improve depth maps, GCA and developable surfaces concept, well data (including available electrical logs, dipmeter, core descriptions, calcite analysis in cuttings, drilling and production data), water-well data (has allowed to provide a validation in quantifying the fractured zones and the orientation of producing fractures).
Drilling techniques - Underbalanced drilling
Matrix permeability and porosity in the target reservoirs are provided by a range of fissures ranging in size from a few millimetres length up to perhaps metres length and millimetres breadth. There is no intergranular porosity. This contrast with conventional fissured reservoirs which are traditionally modelled as dual porosity. The Castillo reservoir effectively has a continuous range of porosity and permeability.
The almost complete absence of intergranular porosity has made the reservoirs extremely susceptible to lost circulation and gas kicks, with severe formation damage to the fissures by the mud weights used to bring the gas kick under control.
Underbalanced drilling is a new technology which has been used to reduce damage in dual porosity systems by allowing the well to flow whilst being drilled.
The current project seeks to extend the methodology to reservoirs where all porosity and permeability are provided by fissures.
Fields of science (EuroSciVoc)
CORDIS classifies projects with EuroSciVoc, a multilingual taxonomy of fields of science, through a semi-automatic process based on NLP techniques.
CORDIS classifies projects with EuroSciVoc, a multilingual taxonomy of fields of science, through a semi-automatic process based on NLP techniques.
- natural sciencesmathematicspure mathematicsmathematical analysis
- engineering and technologyenvironmental engineeringremote sensing
- social scienceseconomics and businesseconomicsproduction economicsproductivity
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Call for proposal
Data not availableFunding Scheme
DEM - Demonstration contractsCoordinator
48001 Bilbao
Spain