Status and the Future Perspective of Drilling Engineering Technologies in Middle East Carbonate Reservoirs

PetroChina has acquired 14 assets in five countries in the Middle East, with more than 3200 wells drilled, including more than 1100 wells drilled in the operator’s assets. Middle East carbonate reservoirs typically have 4–7 sets of reservoirs from the top to the bottom, and well depth, temperature, and pressure exhibit a dramatic variations. A cluster platform for drilling is usually adopted based on a three-dimensional well network and multi-well type combination. The lithology and pressure system of the thick carbonate formations are complex, with alternating soft and hard formations and complex lost circulation channels. The paradox of loss and wellbore collapse in the same zone is prominent, and lost circulation, wellbore collapse, and pipe sticking frequently occur while drilling. Therefore, the drilling engineering technology progress and practical achievements of PetroChina and western drilling service companies in this region over more than 10 years were systematically summarized, and the preventive measures for lost circulation in carbonate rocks as well as the remedies were introduced. Also introduced were Middle East-based typical weak formation collapse prevention technology, and directional well drilling technology. The gap between PetroChina and western companies in drilling in this region was analyzed. In addition, based on the current drilling problems and the new situation and requirements of future development of oilfields in the Middle East, it was pointed out that future drilling engineering in the Middle East will face the development needs of deep reservoirs, low and ultra-low permeability reservoirs, large pad drilling, intensified zonal injection and production, and the reentry of old wells. All provide a reference for the future development of drilling engineering technologies in the Middle East.