Seismic Inversion and Resistivity Inversion While Drilling Methods Application for Reservoir Geometry Characterization

The challenge of construction horizontal well is reservoir geometry especially in the clastic environment such as fluvial distributary channel which has multiple uncertainties such as geological structure and geometry uncertainty exist in the form of channels with variable continuity, thickness and depth. The key for having a successful horizontal well is reducing uncertainties of geometry. Through modeling of seismic inversion, multiple geological and drilling scenarios can be explored prior to drilling, and the reservoir geometry model is updated in real time while drilling by inversion of resistivity. The paper only defines the geometry/reservoir architecture by making a model of seismic and resistivity inversion quantitatively and accurately before drilling,and will be updated during the process of drilling and after drilling. This application is used in the horizontal well construction with complex geological structure and challenging stratigraphy environment such as delta or thin reservoir so that the geo-model is lack of confidence and low accuracy although it has the adequate amount of offset well around it or pilot well. This condition will cause the high geometry uncertainty in the well construction. This combination technique has been used and proved in Niru field.