Multizone Horizontal Openhole Gravel Pack with External Zonal Isolation and Inflow Control Devices Allows for Production of Left-Behind Reserves in Sand-Prone Reservoirs

Abstract

Oil production from the Llanos foreland basin in Colombia is seriously affected by sand production and high water cut. Sand production has been successfully controlled with horizontal openhole gravel packs; however, early water break-through causing water cuts as high as 90% remained a challenge. As a result, operators were forced to shut down some new wells just a few months after placing them on production. A new production logging approach was performed in five horizontal Hocol S.A. (subsidiary of Ecopetrol) wells. In terms of reservoir behavior, the results revealed the following: rapid swelling swell packers were swelled using a new swelling fluid that allowed the swelling to take place before gravel packing the well. Once the swell packers were swelled, the gravel-pack operation began and it was confirmed that every segment was gravel pack, even after the swell packers were in place, thanks to the implementation of downhole gauges throughout the completion. Once the well was completed, the production group installed selective production and inflow control strings to produce the well.The first completion installation was performed in July 2013. The operator performed characterization tests for each productive sand, with results for each sand indicating successful zonal isolation. The results also provided valuable data for reservoir characterization and selection of reservoir management strategies. The addition of new reserves confirmed the value and effectiveness of this new completion technology and its application.