Applying Innovative and Cost Effective Approach Through Remote Field Appraisal Testing with a New Completion Application, Abu dhabi, UAE
Authors: Hegazy Gehad M. 
Published: November 2016

One of the main challenges in testing a remote field with no available facility, is the issue of produced oil disposal. Flowing the produced oil through tie-in pipes or trucking it in case of short distance or nearby facility availability can be considered a solution, however this also could be risky in case of oil spill.

Oil re-injection becomes one of the solutions to avoid risk and high cost. Although ADCO is applying this technique for all short term testing periods, oil is re-injected back in the reservoir at the end of the test. As for long term appraisal testing of horizontal wells, large volumes of produced oil needs to be controlled.

ADCO recent appraisal well were long term test (LTT) production was successfully completed utilizing out of the box idea that is applied for the first time globally. The project objective was to perform LTT at high rate to acquire dynamic data and update 3D dynamic model. Furthermore to confirm the feasibility of early production without pressure support, construct more reliable field development plan and identify reservoir boundaries while proving up side reserve.

Well-03 was horizontalized through main producing reservoir for 60 days of LTT (4000 BOPD). Since the field is located approximately 80 km to the nearby field and no surface facility exists to dispose the produced oil, ADCO Exploration Team studied 4 oil disposal options ; Flaring, Trucking, Storing and re-injecting in the same reservoir or to drill a new disposal well. Costs were ranged from 5 to 7 million in addition to the high risk associated.

Exploration Team proposed a "first application worldwide" new completion concept, which maximizes the well utilization by completing with dual completion string in order to avail the chance of testing and injecting oil into two different reservoirs simultaneously in the same well.

This option was never practiced anywhere in the oil industry and was considered as the most economical application. Moreover it was less risky and suitable for early execution.

In order to evaluate this option, the short string (upper reservoir) was stimulated and injectivity test was performed which confirmed good injectivity while evaluating the long string down hole gauge data. Then long string was placed on production at 3600 bopd for 20 days un-interrupted and injection in the short string was also resumed for disposal of produced oil successfully.

The other considered option would have been a huge tank battery/tank farm of 250 tanks required to handle 80,000 Bbls of produced oil. Operationally to have 250 tanks at the well site for 60 days production would have been extremely risky and required a high cost US$ 5 MM.

This innovative approach for production and injection simultaneously in the same well saved time, excessive money and delivered the project successfully with minimized HSE related issues.

This Invention also provided a road map for remote well testing application in all ADCO fields. Also extends the idea for placing Injection - Production in one well which will save 40% from any project CAPEX.