ADCO aspires to push the established local boundaries via a new drilling campaign to develop 24 long horizontal wells. These wells have 9,000 ft of horizontal section in deep and tight reservoirs targeting two zones that are only 3 ft thick separated by a stylolite. The challenges of this project include drilling 1,500 ft. TVD deeper than previously done to land the wells, stepping down through 3 ft stylolite and extending the horizontal section 260 % further than the typical wells (3,400 ft) in the same reservoir. To reach the proposed thin target requires intensive engineering work in the planning stage (e.g., selection of downhole tools, casing selection, trajectory planning, and mud/chemical selection.

The project started with pilot wells of 6,000 ft and 7,000 ft horizontal sections to gather information before proceeding with the 24 long horizontal wells. The front end engineering phase was performed to ensure the capability of the chosen rig. Additional simulations were performed for critical operations; this resulted in the successful run of 9,000 ft of slotted line to TD. Detailed modeling and selection of appropriate LWD measurements were carried out to land the well and geosteer the long horizontal hole successfully throughout the reservoir. Lab tests were carried out for the selection of the lubricant to be used under such challenging reservoir conditions. T&D models were calibrated while drilling the pilot horizontal sections to ensure that the first ERD well could be delivered safely, meeting all well objectives.

All learning from the pilot wells was captured and, as a result, the first ERD well in a deep and tight reservoir was drilled to TD. This well achieved the longest well drilled with a chemical R/A source in the UAE. Excellent geosteering work was achieved for the successful well placement. The hole was drilled and tandem slotted liners run to bottom smoothly. ECD management played a vital role to minimize losses since the well was drilled close to its fracture limit. Lubricant proved to be compatible with the mud at high temperatures (+ 280 degF) avoiding foaming formation. All sections were drilled shoe-to-shoe successfully.