The Symphony™ Profile distributed temperature array system was deployed for JODCO Exploration Ltd (JEL) to acquire temperature profile data during the entire sequence of drillstem test (DST) operations, from run in hole to perforation, stimulation, flow, and produced oil reinjection. High-resolution temperature sensors installed on the tubing conveyed perforation (TCP) system provided data throughout operations, enabling a comprehensive review of completion effectiveness. In addition, the test confirmed the reservoir behavior consistency.
Identification and evaluation of fluid movement and inflow zones across the tested formation was JEL's main goal of the operation. Additionally, the ability to interpret the reservoir response evolution through various stages of operations would provide a valuable understanding of the nature of the formation. Due to the configuration of the DST-TCP string, well intervention was not a feasible option. To execute any well intervention operation, such as wireline logging or coiled tubing stimulation, separate runs would be required to perforate the reservoir. Evaluating the feasibility and the rig costs, JEL decided to proceed with the operation without well intervention, using a single DST-TCP run.
The Symphony Profile distributed temperature array system was suggested to provide accurate temperature measurements across the entire test interval throughout all injection and flowing sequences.
The array can be installed on the TCP system or strapped to tubing. It immediately acquires data along the entirety of the wellbore during run-in-hole and pull-out of‑hole sequences and across the target intervals throughout operations. The Symphony Profile distributed temperature array system enables reservoir response monitoring of each individual sequence: fluid front movement when pumping down, tracking the evolution of acid intake during stimulation, monitoring fluid returns during clean up, inflow zones during the main flow test, and intake profiling during fluid reinjection and well killing.
The Symphony Profile distributed temperature array system was successfully installed and run along with the TCP system, enabling JEL to acquire temperature profile data starting from the initial static condition to perforation.
Postjob analysis of the acquired temperature profiles showed that the perforating system detonated across the entire target zone. An immediate warm up was observed across the interval before the heat released by the detonated TCP system diffused within the wellbore.
The array system then provided a detailed timeline of acid stimulation operations, showing first acid arrival at the top of the perforations marked by a localized warm up due to the exothermic acid reaction with the formation. It also highlighted the presence of a thief zone, taking up all injected acid and preventing acid from reaching deeper zones.
