StimWell Services completed a series of acid fracturing treatments on three subsea wells in the central North Sea in the spring of 2014. This work was unique as it was the first time that a large high rate acid treatment was successfully placed by a stimulation vessel through a light well intervention vessel (LWIV) in the North Sea.
Previous treatments have been pumped from the LWIV themselves or with a stimulation vessel via a semi-submersible rig. Pumping a treatment with skid equipment significantly limits the treatment size and rate. Treatments pumped via a semi- submersible rig are also more time consuming and expensive.
This arrangement with the LWIV & stimulation vessel allowed for a higher rate acid treatment to be pumped with significant cost & time savings.
Numerous benefits from a Safety and Efficiency stand point resulted from the way the work was performed and has set a precedent for future work in the field.
* The weight on the hose hanger in the event of an EQD only changes by .15 MT from normal operating conditions with the hose connected.
* A retrieval system was designed to be able to safely and efficiently retrieve a disconnected hose back onto the Island Patriot's hose reel.
The project was a major success for all parties involved and by being able to safely and efficiently perform large high-rate acid stimulations between the vessels the operator was able to perform the proper stimulation treatments for the wells.
Overall cost for the project was 2/3 less compared to carrying out the work with a semi- submersible and production from the wells exceeded expected production.
Beacon Innovation Centre
c/o Copco A/S