As part of ongoing efforts to develop greater gas and oil resources in the UAE, appraisal of several fields discovered decades ago accelerated in 2015 and 2016. Drill stem tests (DSTs) during appraisal are of particular importance; the production and reservoir data gathered during DSTs help determine commercial viability and support the planning of field development and facilities design. Abu Dhabi Marine Operating Company (ADMA-OPCO) was looking for a solution that allows continuous real-time monitoring and well performance evaluation and ensures that test objectives are being met, thus optimizing the test program for best operational efficiency.

A wireless acoustic telemetry system was chosen and successfully deployed for the first time in several ADMA-OPCO projects to provide surface readout of bottomhole gauge data and two-way communication control of tools, such as test valves, fluid samplers, and perforating guns. With the telemetry system, bottomhole data was rendered available throughout operations, from run-in-hole to well killing operations, and was transmitted along with surface measurements to a data repository that was concurrently accessible to operating company engineers as well as the service company support personnel. The availability of real-time bottomhole pressure and temperature readings at the rig and to offsite engineers for analysis and in-time decision-making ensured that tests were executed in the safest and most efficient way while also maximizing the value of information gathered.

Real-time transmission of test data enabled early diagnostic assessment of reservoir behavior and performance and identified deviations from expected responses as they developed. For example, the expected well response following matrix acid stimulation could be estimated from early prestimulation data, even when the well did not actually achieve stable flow to surface. These early diagnostic data helped to justify running stimulation operations and provided a first reasonable estimate of target rates during the main test sequences as well as the opportunity to continuously update the test plan.

The data available for monitoring and initial interpretation during operations was of equal quality to that gathered by memory pressure recorders, and the use of a flexible data transmission plan focusing on key test sequences provided a descriptive capability equal to that conventionally available only after test completion.

The deployment of surface readout of downhole data combined with real-time data transmission and remote support was performed for the first time in the UAE during those appraisal tests and has since become a standard practice as a result of the operational benefits achieved as well as the enhanced interpretability of data gathered.