Optimum Horizontal Well Placement in Very Low Resistivity Reservoir With a Directional and Deep Logging-While-Drilling Technology

摘要

In the Sub-Andean basin areas of Peru, Colombia and Ecuador, important reservoir targets present very low resistivity range and also very low resistivity contrast between pay and non-pay. These unique conditions constitute a challenge in relation to the ability to map the reservoir boundaries and to allow the successful navigation of horizontal wells in thin target zones. Conventional logging data are not able to effectively determine the approach or prevent the intersection of a reservoir limit under such reservoir conditions. Therefore, they are not perceived as the best option to optimize geosteering decision making. A new logging while drilling technology, developed by Schlumberger, based on directional electromagnetic resistivity measurements was applied in a horizontal well, recently drilled by Pluspetrol Norte in Peru. The service delivered directional resistivity measurement with deep depth of investigation, which allowed estimating the orientation, distance and resistivity of nearby bed boundaries. The technology was successfully used to navigate the well, optimizing the horizontal length inside the best productive zone and stay at a safe distance from the OWC. The productive behaviour of the well was better than expected.