Acquire high-quality pressure data

When performing drillstem tests, the ability to acquire high-quality pressure data for pressure transient analysis depends on both the location and the metrological performance of the gauges. With conventional installation of memory gauges above the perforation interval, the recorded gauge data can be affected by high-pressure drop in the tubing, string movement, liquid dropout, and fluid segregation effects in the wellbore during pressure buildup. These operational variabilities can mask the actual reservoir pressure response and, quite often, can lead to misinterpretation of well test data or misunderstanding of the reservoir structure.

Many of these issues can be solved by installing memory gauges as close as possible to the reservoir; however this approach is difficult to implement in wells with permanent lower completions utilizing sand screens or gravel packs. Another challenge is the inability to retrieve the information from the memory gauges without pulling out of hole.

Use Signature gauges enabled by Muzic telemetry

For real-time pressure measurements from gauges located close to the reservoir, Schlumberger engineers recommend using Signature quartz gauges enabled by Muzic wireless telemetry. Signature gauges are designed to deliver the best pressure data in any environment, even under the most hostile conditions. This capability was important for an operator conducting a DST because the intensive shock that would be posed by the perforation guns can damage downhole tools.

For constant communication with the gauges throughout the flow test, Muzic wireless telemetry enabled the operator to obtain real-time pressure measurements while monitoring and controlling the downhole reservoir test. This allows for real-time pressure data verification and better-informed decision making.