Horizontal Well Placement in Thin Shallow Reservoir Sands for Heavy Oil Fields Development

After a successful development campaign of Girasol heavy oil field through horizontal wells with more than 90 wells drilled and completed, the efforts and experience of the operator was directed to the development of other assets like Abarco and Under River fields. The fields are located in Colombia Middle Magdalena Valley basin and share a sequence of sandstone channels which were deposited in a fluvial environment associated to braided and meandering streams. The main target sands are located at 1,100 to 1,600 ft true vertical depth, their thicknesses range from 10 to 30 ft. and contain 11 to 13 °API oil. To maximize production, horizontal trajectories of up to 2,600 ft long, equally spaced and laterally parallel have been placed in up to five target sands from a clusters arrangement to minimize environmental impact and to develop the reservoir below the Magdalena River. Well placement under this geologically complex scenario is, in general, difficult to achieve with the use of conventional geosteering techniques, as they generally fail to identify unexpected changes in the reservoir geometry. This risk is minimized by using deep, directional electromagnetic measurements while drilling, allowing a reservoir geometry mapping in real- time, several feet from the borehole.