Publications

The X Field is the world’s largest thermal recovery project. Over 200 horizontal wells drilled with average oil cumulative per well above ~90 MSTB. These wells targeting ultra-shallow reservoirs and various performances is observed. This paper presents a combined an empirical study and simulation, identifying key success factors and leading the 2024 horizontal well drilling success.

The study conducted with three steps, consist of an empirical observation, testing well design using thermal simulator and extracting conclusion for the next horizontal well campaign. The empirical observations start with wells performance classification based on five years cumulative oil. Second, a statistical approach is performed incorporating static data of porosity, permeability, oil saturation, etc. Third, thermal simulation is used to replicate a conceptual horizontal well model in steam flood, adjusting reservoir properties and execution parameters. The findings were used to develop criteria for well selection, tested against the 2024 drilling campaign.

The study reveals some key factors contributing to both success and failure. Success factors are driven by high oil saturation and a thick oil column above the lateral section. Failure factors are driven by incorrect well placement. The simulation tested optimum criteria for horizontal well candidate. Those criteria require oil saturation of 0.3-0.5, oil thickness of 15-40 ft, and high-temperature reservoir. Execution parameters include a toe-up trajectory and parallel structure well placement. The 2024 drilling campaign successfully implemented these optimal criteria, achieved a 20% improvement in first-year oil production compared to previous projects.

This paper presents an integrates empirical reservoir with thermal simulation to establish optimal criteria for ultra-shallow horizontal well in steam flood field. New opportunities were unlocked at suitable reservoir properties, screening out suboptimal candidates, and refining well design to mitigate operational risks. Additionally, the study documents lessons learned and operational challenges in the X Field.