Publications

The sedimentation in the distal parts of the large progradational delta-systems like Mahakam (East Borneo, Indonesia) and Rajang (West Borneo, Malaysia) is mainly shaly, thus one of the major concerns for the explorationists in this kind of geological setting is to find hydrocarbon reservoirs with good petrophysical properties. Gravity gliding accommodated by proximal extension and distal shortening of the sediments are common phenomena in such kind of gentle delta slopes. In particular, reverse faults and the toe thrusts developing in the distal parts of the progradational delta-systems strongly influence the location and geometry of the potential sandy bodies. In order to better understand the complex interactions between deformation and syn-thrusting sedimentation, a series of sandbox models have been realized and analyzed by X-ray computerized tomography. They help us to discuss where to look for the less risky trap configurations, i.e. a sandy channel initially deposited in a syncline and then uplifted by the development of the following fold and/or thrust anticline. To realize this modeling, research has been done to bypass one of the classical limitations of the sandbox models that results from a bimodal material characteristics: weak silicone and brittle sand. The density relationship between both often results in diapirism of the silicone which therefore is a better analogue of the salt than of the shale. Here we propose to mix silicone and brittle sand to obtain other materials, which localize the strain but which are also likely to fold and allow us to better represent the soft deformation mode of these shaly series.