Our customer planned an appraisal well to improve the estimated ultimate recovery (EUR) of their reservoir
Reservoir connectivity is a key uncertainty that impacts field development decisions. Our customer wanted additional insight and data beyond a conventional DST, with minimal incremental cost
An objective for the test was to flow the wells at conditions analogous to a producing well, but standard test durations are insufficient to investigate the volumes that would be accessed under production conditions
Recoverable resources were dependant of demonstrating significant reservoir connectivity, however this was complicated by the geology
Expro Excellence
Expro installed 2 x CaTS™ gauges clamped onto the lower completion below a permanent packer
Another 2 CaTS™ gauges were installed inside the tailpipe on a plug below the packer
Four repeaters were installed below a bridge plug
Four ASMs were installed on a modified debris cap at the sea floor
Four discrete systems were run giving, four independent gauge measurements and multiple redundancy
Value to Client
Use of wireless gauges allowed the pressure buildup duration to be extended from 3 days to 428 days
The higher-cost rig time was used for producing a larger pressure disturbance
The gauges allowed the resolution of the third and fourth reservoir boundaries (with outermost boundaries 15km from the well)
This well test strategy was able to investigate a similar reservoir volume to the planned development wells
The use of multiple gauges contributed to narrowing the range of uncertainty by allowing a tighter drift range in modelling
The results showed that the gas volume in the model was a significant overestimate of the actual gas volume