The transition from completion to production often requires the well to be killed immediately after perforation is completed, thus exposing the formation to potentially damaging kill fluid. To obtain a perforation tunnel with maximum productivity, this transition requires an optimal cleanup and the removal of the perforation damages.
A new underbalanced oriented perforating technique has been successfully implemented in Algeria. It combines the use of a formation isolation valve (FIV) to keep damaging completion fluid off the formation immediately after perforation and a perforating technique that utilizes the dynamic underbalanced method, which cleans perforations with more efficiency than conventional static underbalanced perforating method. In addition, a passive gun-orienting system was used to optimize the perforating process and enhance the well's performance.
The new technique was applied in 2003 to horizontal Well-1, which was drilled by in the Tadrart sandstone formation of the Berkine basin. After successful results in this well, the operator adopted its use in 2005 for two additional wells, Well-2 and Well-3.
The paper describes the application of the new technique to three horizontal wells of the Berkine basin and the evaluation of the related productivity increase vs. the conventional perforating method.