Saudi Arabian oil and gas drilling contractor ADES International Holding has completed the acquisition of rival rig firm Shelf Drilling.
The merger, concluded on November 2025, has created a global offshore drilling powerhouse, with the combined group operating with a fleet of over 80 offshore jack-ups, including more than 45 premium units across the world’s most attractive basins.
The merger agreement was first announced on August 5, 2025, with revised terms disclosed on September 16, under which ADES offered NOK 18.50 ($1.89) per share.
The revised offer came following discussions with Shelf Drilling’s senior management and consideration of the company’s current trading, jack-up market fundamentals as well as $10 million upwards revised cost synergies estimate to $50-60 million on an annual basis, from previously announced $40-50 million.
As of June 30, 2025, the combined company had a total combined backlog of $9.45 billion.