To measure and analyze reservoir pressure, conductivity, gas/oil ratio (GOR), and skin value, it is necessary to run a pressure buildup (PBU) test to the corresponding zone of interest in the well. This paper describes how the implementation of a coiled tubing (CT) real-time fiber-optic (RTFO) integrated system and a retrievable packer were determining factors to successfully develop both PBU in an upper formation and a pressure evaluation in the lower formation in the same run.
To help ensure isolation and evaluation of each high potential zone in the well, conventional methods involve multiple procedures requiring multiple runs. Using the CT RTFO (Vera et al. 2018) integrated system with a retrievable packer, only one run was necessary to complete the PBU program, which involves the isolation and corresponding log of two reservoirs.
This new technology helped the operator overcome challenges and deliver improved service quality. Real-time data acquisition during the packer setting helps ensure correct inflation, and continuous monitoring of the isolated zone during the PBU process helps ensure data accuracy and defines the end of data acquisition time once radial flow has been observed in the pressure transient analysis; therefore, the points previously discussed strongly impact production by optimizing operation time. Avoiding the use of materials such as cement to isolate the mentioned zones made this operation environmentally friendly. The greatest value of this technology is that it makes real-time monitoring of both the upper and lower zones possible at the same time.
The PBU test was successfully developed by determining reservoir pressure, skin, and flow regime of the near zone formation with precision and confidence, which helps the operator make decisions about future stimulations. High-pressure stimulation was achieved, which resulted in 460 BOPD over the initial production. Finally, a downhole ball-drop tool was effectively used to help ensure that packer setup was accurate and to reduce intervention time.