Abstract: Sedimentological Interpretation Using Advanced Automated Analysis of Borehole Imaging Log: Example of Deep Water Deposits

Caline, B.; Ros*, J. B. - Elf E&P; Rabiller, P. - University of Bordeaux; Keskes, N. - Elf E&P

The recent development of borehole imaging log provides high resolution information. A new method has been developed to automatically analyze the image texture to help the sedimentologist to recognize sedimentary facies in uncored wells.

The applied method consists of 4 successive steps:

- Identification of electrofacies using conventional wireline logs. An automated classification is applied and then compared with the lithological description of the core.

- Automated detection of dip and bed limits is provided by image analysis with quality index. Experience shows that the dips identified by these methods are very comparable to those a geologist would pick manually.

- Automated textural classification of the image. The image is automatically analyzed in order to derive for any depth, a single value representative of the texture.

- Sedimentological interpretation of image texture

The image texture and normalized image are visually compared with the sedimentological structures identified in cores. Recognition of the sedimentary structures can then be carried out along the studied interval. In the selected reservoirs, this method allows a first differentiation between hydrodynamic structures, bioturbation structures, debris flow structures, sedimentary deformation and absence of structure (massive appearance).

AAPG Search and Discovery Article #90933©1998 ABGP/AAPG International Conference and Exhibition, Rio de Janeiro, Brazil