Economic Comparison of Intelligent Wells in Simultaneous Production of Oil and Gas Reserves From Single Wellbore

Maximizing oil. recovery in thin and ultrathin (less than 30 ft) oil columns is a challenge as a result of coning or cresting of unwanted fluids into the wellbore in both vertical and horizontal wells. There is considerable oil left behind, above the well completion in the reservoir. This may also occur in horizontal wells when bottom- or edgewater encroachment or invasion takes place. The development of the gas resources from these reservoirs is a major challenge because regulators want an optimal development plan for the oil rim before project approval is made. This can delay upstream gas supply to liquefied-natural-gas (LNG) projects and grind clown project value. A smart development strategy has been proposed for the development of these challenging reservoirs. This involves the use of intelligent multilateral wells in simultaneous oil and gas development; the first (top) horizontal-lateral-well legs of the multilateral well will be completed at the crest of the reservoir in the gas cap. The second (lower) horizontal-lateral-well leg will be completed just above the gas/oil contact (GOC). Extensive numerical reservoir-flow simulation has been used to demonstrate the ability and possibility of using a single wellbore for simultaneous oil and gas production. This proposed development strategy will provide high impact on the asset of such oil and gas reservoirs by providing a cost-effective-technology solution. The numerical-simulation results show that the intelligent multilateral we:1 will significantly improve the overall cumulative production of gas and oil from a thin oil reservoir with a large gas cap compared with conventional wells and also provide the opportunity for automatic gas lift for low-gravity crude (degrees API). This paper (1) presents the use of intelligent multilateral wells to produce oil and gas from the same wellbore simultaneously in the thin oil reservoir and (2) provides information on the delay and reduction of excess production of unwanted fluids (water) during oil and gas production from thin oil reservoirs using intelligent-well technology, including cost effectiveness.