A New Approach to Define and Optimize the Horizontal Oil Well Trajectory in a Fractured Reservoir

摘要

One of the most important tasks of a reservoir engineer is to develop new plans in order to improve field performance. Production histories and efficacy of horizontal wells around the world during the last three decades prove the significant role of this kind of well in increasing productivity and achievable reserves in oilfields. Horizontal wells have also shown great advantages over naturally fractured carbonate reservoirs. There are various and complicated factors which affect horizontal well performance. Besides reservoir features like porosity and permeability distribution and fracture properties, parameters like well placement and trajectory, well scheduling and completion methods have the main effects on horizontal well performance. The main objective of this article is to study the effect ofhorizontal well location and trajectory on its performance in a heterogeneous fractured reservoir. Variables considered are well location, well length and well direction. The selected objective function for comparison of different plans is the field cumulative oil production after 20 years of single horizontal well drilling, simulated by Eclipse. Finally by screening criteria, focusing on best results of initial sample points, testing the guess answers and repeating the process we try to approach the optimum well trajectory. The results show that we can obtain the most productive zone and direction for horizontal well drilling. Further investigations prove that geological conditions of the reservoir also verify the validity of our results.