Eliany Teran, Senior Petrophysicist
Featured Domain: Formation Evaluation
Featured Technology: Geolog®
Rock texture is an important parameter that must be considered when performing a petrophysical characterization of complex carbonate reservoirs, due to its relationship with the depositional and diagenetic mechanisms, and its effect on fluid flow capacity of the rocks.
The workflow presented in this lecture describes a methodology for extracting texture information from resistivity borehole image logs in order to generate a high resolution ordered textural facies log. When integrated with conventional logs, this greatly contributes to the improvement of facies models.
Two approaches are combined to extract texture from resistivity borehole image logs. The first one relies on the quality index from detected stratigraphic lamination dips, such as contrast, lamination and planarity. These are used to delineate laminated intervals, and characterize them in terms of dip facies by mean thickness, lamination density, mean contrast and mean planarity. Considering the fact that dips are irregularly spaced and computed at point level, the dip facies are also computed at point level. To overcome the challenge of describing continuous rock intervals, either laminated or not, by means of facies observed at irregular depth, a histogram upscaling technique was applied. A continuous and regularly sampled log was obtained, and it was possible to reconcile high-resolution data with conventional logs to qualify intervals in terms of diagenetic or depositional facies.
The second approach comprises the texture detection based on covariance information about resistivity image logs, and a posterior facies definition using statistical and unsupervised algorithms that guide the texture identification as a function of contrast.
is a Senior Petrophysicist at Emerson Paradigm. Prior to joining the company, she worked at PDVSA as a reservoir engineer and petrophysicist. She has a degree in Petroleum Engineering from Universidad del Zulia (Venezuela), and a graduate diploma in Petroleum Geoscience from IFP (Institut Français du Petrole, France).