Expro Excellence Wireless Well Solutions… · beyond the end of the drill stem test (DST) period...

Objectives

• After testing the initial Norvarg discovery well(operated by Total in the Norwegian BarentsSea) the vision of the reservoir was for largechannel sands having better reservoirproperties than tested in the first well – theNorvarg 2 appraisal well was planned withthe objective of investigating uncertaintiesregarding reservoir deliverability,compartmentalisation risk and the fluidcontacts

• A particular objective was to demonstratethe contribution of other geological facies byperforming a long duration pressure build-upbeyond the end of the drill stem test (DST)period

• To minimise costs, it was a requirement forthe well to be permanently abandoned atthe end of the DST without any requirementfor a further semi-sub based wellintervention

Expro Excellence

• Three CaTS wireless transmitting gaugeswere deployed externally mounted on thetailpipe below a permanent packer andabove the TCP guns

• The DST string was stabbed into thepacker and a conventional short durationwell test performed

• At the end of the final pressure build-up(PBU) a sliding sleeve valve in the lowercompletion was activated to isolate thereservoir zone being monitored from theupper DST string

• A well kill was then performed above thepacker, the DST string recovered tosurface and the well plugged andabandoned by setting cement plugs inaccordance with industry legislation

• A CaTS subsea receiver assemblyfeaturing dual redundancy capability wasdeployed from the rig on drill pipe andlocated on the abandoned well head

Value to client

• High quality pressure build-up data wasrecovered from all three gauges for aperiod of nine months after well plug andabandonment

• The subsea receiver equipment and finalwell head retrieval was achieved costeffectively using services deployed from asupply boat

• Interpretation of the PBU data identifiedtwo no-flow boundaries 130m and 280mfrom the wellbore that were not observedduring the course of the normal DSTperiod

• The vision for the large channel sandswas more likely to be a channel belt withindividual smaller channels having internalflow barriers, meaning that additional wellswould have been required to develop thefield compared to what was known priorto collecting the data

ContactFor further information, please contact:

wireless@exprogroup.com www.exprogroup.com/wws

/ Expro ExcellenceWireless Well Solutions

Expro E x c e l l e n c e exprogroup.com Wireless Well Solutions

CaTS™ wireless gauge technology detects flow barriersin the reservoir during extended post-abandonmentpressure build-up monitoring

Reducing uncertainty in connectedvolumes during Barents Sea appraisal

CaTS gauges mounted on the tailpipe

Test string configuration showing threeCaTS gauges mounted on the tailpipe

WWSCS Norvarg Case Study_A4 16/11/2016 12:16 Page 1