Publications

The Bekapai oil and gas field is located offshore to the south-east of the Mahakam delta. The structural geology is a Pliocene four-way dip anticline elongated in NNE-SSW trend, cut by NNW-SSE normal faults. The structural scheme (double truncation “Y” fault) was difficult to model. The classical Corner-point gridding method cannot handle correctly the double-truncation fault pattern due to its algorithm limitation. During 2006-2010, it was the period of “Puzzle” 3D geo-model where the Bekapai geo-model was split into several 3D grids due to its fault complexity and limitation of the technology. In 2011, an in-house structural modeling workflow was proposed to avoid double-truncation by splitting the full-field model into several sub-grids. However, this workflow is very heavy and time-consuming (mainly in case of up-dating). A new structural framework algorithm called Volume Based Model (VBM) has been successfully tested. The algorithm is very different from the previous algorithm which relies on the calculation of surfaces as iso-value of a volume attribute. The main advantages of the VBM module are better managing the iso-proportionality of zones, handling the interpolation in a small segment, and smoother interpolation in the edge of truncated zone. Following that, the horizons are modelled directly with “Horizon modeling” in “Structural framework”, and as a consequence the split of the full-field grid in sub-grids is no longer needed. This make the gridding workflow with VBM become efficient. Several 3D Grid quality control (QC) parameters, such as well tops mistie, cells regularity, cells angle,cells inside-out, cells width, cells height, and cells bulk volume were created and all those demonstrated a good quality of the 3D Grid. This paper will highlight the technological breakthrough in structural modelling and its impact in geo-model workflow efficiency with a good quality result.