Seismic Facies Mapping-Getting More Geology into Your Play.

Abstract

Seismic facies mapping is an underutilized tool for getting extra geology in to your exploration, or development. It is a key component of palaeogeography mapping that help show different types and locations of seals and reservoirs. Both manual and automated facies mapping, on 2D and 3D seismic, when calibrated to local wells, can help de-risk crucial components of a play. In many areas today where deep water or new frontier exploration is undertaken, there is often little or no well control and seismic facies mapping, allied to analogues, may be your only tool for getting at the geology in your palaeogeography maps. This talk will apply geological models to, and discuss, the construction of manual seismic facies maps which are then used to guide automated facies map work. Manual facies mapping is undertaken once sequence boundaries have been mapped and named. Each different facies identified is given the name of upper and lower boundaries and the facies name and then the horizon is picked so that the facies extent is shown on a base map. Once completed, polygons encompass this facies. The final map uses all polygons constructed, along with well logs for that sequence. Automated facies maps start with RMS and maximum amplitude maps of the sequence, then possibly of proportional slices within the sequence and then we may construct waveform facies maps or spectral decomposition maps of the interval. All these maps are considered with the interval’s isochron map and at least gamma log windows at wells, with appropriate geology transcribed to finally construct the palaeogeography map of the interval.