Perforating with Deep Penetrating Guns Followed by Propellant Treatment Yields Results in Tight Reservoirs - UAE Case Study

Abstract

A recent exploration well in the UAE was drilled through a gas zone in extremely tight carbonate rock. The evaluation success of this interval hinged on the production of gas to surface to confirm the presence of hydrocarbon. After drilling the well and running the completion the rig was demobilized and the testing work was carried out using rig-less techniques. An abrasive jetting stimulation technique was attempted but was unsuccessful. The zone was finally tested using wireline conveyed perforating guns followed by wireline conveyed propellant stimulation equipment. After the first perforating run with a premium deep penetration gun system gas started to accumulate at surface confirming that a connection had been made to the reservoir. This accumulation in the pipe was bled off occasionally and continued to build through the remaining perforation runs. After perforating was completed each interval was treated with a propellant assembly which increased the rate of gas build-up significantly indicating value of the propellant treatment. The entire job progression was recorded with a surface pressure recording device. This paper will review the obstacles encountered to test this tight unconventional reservoir, the planning for this job including the risk assessment and modeling for the propellant runs, along with the status of the perforating and propellant equipment as it was returned to surface. The techniques used to confirm this reservoir contained gas that could be produced to surface have applications in many unconventional reservoir exploration wells and for many operators in the region.