S-Oil CEO Hussain A. Al-Qahtani and some 100 company staff participate in a new year's trekking event at Seoul Grand Park in Gwacheon, Gyeonggi Province, Friday. During the event, the CEO urged united efforts for the successful completion of the Shaheen Project, the refiner's $7 billion mega project building a large-scale petrochemical plant in Ulsan by 2026.