Mapping of fracture density in chalk reservoirs
The goal of the project has been to establish a method of fracture density detection from seismic data. The project has its origin in the PRIORITY project and has made use of the interpreted image logs from PRIORITY.
The project will develop and demonstrate a method for mapping of fracture density in chalk based on the seismic data and calibrated with well log observations. The project is based on data from PRIORITY and will therefore focus on lower creaceous. The lower cretaceous data is difficult to work with wherefore the new method also will be used on upper chalk where the method can be tested and calibrated. The data from upper chalk is selected in co-operation with Mærsk Oil and Gas. The project is started with a phase where the influence of the fractures on the seismic data is described. In the project a new fracture density attribute is developd. It will map the variations of the fracture density from the seismic data. The single fracture is beyond seismic resolution so it is variation in the fracture density that is mapped. The method will be verified by comparison with fracture interpretation from cores and image logs. Previous work with seismic attributes, especially coherence techniques, performed in co-operation with Amoco research in Tulsa and Coherence Technology Company in Houston shows that it is an advance to work on inverted seismic data. The seismic data will therefore be inverted to acoustic impedance as an extra product in the project. A product that also can be fruitful for other parts of the PRIORITY project
The estimated attributes have also been delivered to the PRIORITY project. The work has been focused on three seismic attributes: Stratigraphic Correlation Cube; Attenuation Cube; and Acoustic impedance. The method has been tested on seismic data both lower and upper cretaceous but, unfortunately, the variation in the fracture density from the image logs has in none of the cases really been sufficient to validate or confirm the assumptions behind the project. So the project has neither been able to show that it is possible to perform fracture density determination in chalk from seismic data nor has it shown that the suggested method does not work
Key figures
Category
Participants
| Partner | Subsidy | Auto financing |
|---|---|---|
| No entries available. | ||
Contact
Kroghsgade 1
DK-2100 København Ø, Denmark
Mørch Pedersen, Jacob (afdelingsleder), 35266011, jmp@oedan.dk
Øvr. Partnere:
