Horizontal Well Standoff Performance and Exploitation of Thin Oil Rim

In this paper one of the areas of conflicts observed with the performance of horizontal wells standoff with respect to development of thin oil rim reservoirs is examined. In a technical paper as part of the critical review of literature on the exploitation of thin oil rim reservoirs with large gas cap and aquifer, this author had highlighted the problem. As part of sensitives in horizontal well standoff, Cosmos and Fatoke (2004) tested three positions; one-third, centre and two-third positions from the GOC in a Niger Delta field. They concluded that the landing closest to the GOC (one-third position) yielded lowest Oil compared to the centre and two-third positions. Surprisingly the work done by Sai Garimella et al (2011) in a 60ft Ghariff & Al Khlata shallow marine low permeability sandstone reservoirs in a field in Oman showed a different result with the one-third position indicating an optimum recovery from a horizontal well. Interestingly both authors positions on the performance had support from other authors. This study used a 3D reservoir model, investigated different horizontal well standoff performances and applied permeability reduction to simulate different reservoir quality. The objective was to see if the reservoir quality was a factor in the different horizontal well standoff performance seen from different regions of the world while noting their different depositional environments. Results from the investigation is presented in this paper and shows a different trend from both authors mentioned above.