STENA DON’S SUCCESS OFFSHORE MOROCCO

In September 2021, Stena Drilling were delighted to secure a contract with Chariot Energy Ltd to carry out drilling using the semi-submersible unit, Stena Don, as part of the Anchois Gas Development project in offshore Morocco. This was a very exciting prospect for all involved with the rig, as this was the farthest South that the Stena Don had ever worked.

Stena Drilling and Chariot agreed that drilling operations on the Lixus licence, offshore Morocco, would commence on 15th December 2021, lasting approximately 40 days. 

Following completion of its 5-year Subsea Blow-Out Preventer (BOP) recertification the Stena Don commenced preparation for drilling in the Lixus field to appraise the Anchois Gas Development. Once the cargo was loaded on-board the rig set sail from Scapa Flow in Orkney to the Lixus field in Morocco. The planned sail was due to last approximately 14 days, however, due to the time of year and potential risks involved with leaving Scapa Flow, the decision was taken to leave two weeks early to ensure that they would arrive on location on the agreed well ‘spud’, or commencement, date of December 15th. The Stena Don departed Scapa Flow on the 16th November and sailed to Belfast, where the team planned to complete their remaining sea trials and perform a crew change. 

The team made the right decision by leaving Scapa Flow early, as the wind was around 15 knots upon departure. Had they waited another week, they would have been forced to battle 60-80 knots gusts of wind which could have prevented them from leaving on time, and potentially causing delay to them arriving on location.

Upon leaving Belfast, the Stena Don was hit by storm Arwen. But being the harsh weather machine that she is, the rig was able to power through the storm and continue onward south safely. 

The Stena Don arrived on location in Morocco, ready to jump into action on the 13th December. The first task was to perform a crew change which held its own challenges. One-month previously, Morocco had closed its borders to foreign travellers due to the current COVID pandemic, so getting into the country was going to prove very challenging. Chariot Energy approached Moroccan local authorities who allowed the Stena Don team to enter the country via a charter flight. Crew were then transferred to the rig by boat. A couple of the team who were to be based in country were allowed in, but no other personnel could stay over-night in Morocco. This process worked well and was repeated for the first two crew changes. Eventually a method of crew changing through Algeciras in Spain using commercial airlines was established with crew sailing directly from there to the rig, which removed the need for the charter flight.

The team commenced well operations on 15th December 2021, with the ‘spudding’ of the Anchois-2 well. Spudding is the term used to define when the drilling rig first touches the seabed with the drill bit. The Stena Don team then proceeded to ‘jet’ the 36” conductor into the seabed which is effectively washing away the sand inside the conductor pipe as it travels further into the seabed until the required depth is reached. This conductor pipe then acts as the structural foundation for the well and all subsequent casing strings are hung off inside the large 36” diameter pipe. The rig then drilled the 26” hole section, followed by running and cementing in place a 20” diameter casing string with an 18 ¾” well head to accommodate the Subsea Blowout Preventer (BOP). The Stena Don owned BOP was then splashed below the water line, ran subsea and landed on the well head. The BOP links the Stena Don drilling rig to the well being drilled and allows the drill crew to drill smaller diameter hole sized sections of the well which have a higher-pressure envelope. The ability to have a heavy mud column in the well, as opposed to sea water, and the rig-owned BOP are the critical safety measures in place to ensure that the Stena Don rig crew are able to safely drill potential zones where hydrocarbons may be encountered. With the BOP safely landed on the wellhead the crew drilled the 17 ½” section and the 12 ¼” sections of the well to the required depth for Chariot to assess the hydrocarbon potential of the reservoir. All this work was completed with minimal down time, and the Stena Don crew worked closely with Chariot to identify opportunities for making operations more efficient at every stage of the programme.

Upon completion of the Anchois-2 well, the crew moved the rig to the Anchois-1 well (an existing well drilled approximately 12 years previously by another operator) to perform some checks of the well for Chariot using the Remotely Operated Subsea Vehicle (ROV) on-board the Stena Don. After completing a short scope of work at Anchois-1, the Stena Don commenced preparations to depart the country. 

One of the major issues that the Stena Don crew faced was the challenges that arose with the COVID-19 pandemic. There was a total of 9 COVID-19 cases onboard over the period of the contract. This was managed well onboard and their COVID isolation cabins were used in compliance with Stena Drilling’s COVID action procedures, which allowed the team to continue working without disruption.

Despite these obstacles, the project was an overarching success. The Stena Don rig safely and efficiently drilled the Anchois-2 well. Preliminary interpretation of data found throughout this project confirmed the presence of significant gas accumulations in the Anchois-2 well, with the discovery exceeding Chariot’s expectations. 

At the end of this successful campaign, the Stena Don set sail from Morocco, destined for Scapa Flow on 20th January 2022, with a planned stop-off in Belfast to perform a crew change and load the pilot required for entering Scapa Flow. The team arrived in Belfast on January 28th to perform the crew change, where once again, they were hit by severe weather.  On the journey from Belfast to Scapa Flow, the team encountered winds gusting up to 93 knots. During this time, the Stena Don moved into sheltered waters before continuing her transit to Scapa Flow. 

The Stena Don arrived at Scapa Flow on 4th February 2022, with anchors deployed and the rig safely moored within 24 hours. As soon as the Stena Don was moored up the team had the pleasure of welcoming an audit team arriving to assess the rig for another potential contract. This delighted everyone on-board and provided confidence that the rig was still the unit of choice in the UKCS despite the recent journey to warmer regions. 

The contract in Morocco was a real testament to the Stena Don’s capabilities as a unit that can work anywhere and get the job done to the highest standard. When you combine this with a great team effort – it certainly was a job well done! 

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