Abstract
The intelligent well system (IWS) is normally operated with multiple-zone production/injection in the commingled condition, which makes it difficult to predict the effect of IWS operations on well flow performance and zonal deliverability. This is because: 1) The production string, downhole control equipment and isolation tools separate production fluids into different flow paths (tubular/annulus), and the different flow paths have different resistance to each zone's outflow; 2) the reservoir and fluid properties of individual zones are normally different, and these varying properties will cross-impact the outflow of each other's zones when fluids are commingled; 3) downhole choking operations will impact the wellbore pressure profile, thus impacting the production profile from each zone; and 4) Simulate the fluid temperature profile and the effect on pressure and flow profile for the IWS completion is a complex task. The current published works have not covered the whole spectrum.
To address this situation, an analysis tool has been developed, combining the developed comprehensive thermal model with integrated inflow performance relationship (IPR) technology and innovative operation point searching algorithm. For any downhole choking operation scenario, the flow allocations and profiles of wellbore pressure, temperature and fluid velocity can be predicted. This provides the operators insight into how to choke the downhole valves to meet the production enhancement target. It also gives an insight of how we customized the design of the downhole valve settings to achieve the production objectives. In addition, the threshold pressure at commingle point to control crossflow can be predicted through this technology, which provides potential ability to control/monitor possible crossflow of multiple-zone production through the intelligent well monitoring and control system. For demonstration purpose, a potential case study of a typical deep-water two-zone IWS was used for analysis. Model verifications were provided by comparison with the third-party software. Analysis and comments of the comparison have been provided.
