Model-Based Production Strategy Optimization for a Heavy Oil Reservoir Considering Waterflooding and Intelligent Wells

Abstract

ABSTRACTHeavy oil reservoir production is complex due to low oil recovery factors and the difficulty to flow from the reservoir to the production field system. Decision-making procedures for developing and managing a production strategy are also hard because all variables, uncertainties, and physical phenomena must be studied to avoid potential wrong decisions. Waterflooding (WF) is the most common method to recover oil, but the management in heavy oil reservoirs is difficult due to low sweep efficiency caused by a high water-oil mobility ratio and high production of water. The WF management can be improved by using intelligent wells (IW) equipped with inflow control valves (ICVs) because they are capable of controlling multiple production/injection zones.The optimization of WF with ICVs as production strategies is also challenging. It requires considerable effort due to the variables and principles to be studied. As for IW with ICVs, an extra work is necessary since more design and operational parameters play a significant role in the reservoir management.The objective of this work is to perform a nominal production optimization for the development and management of a heavy oil reservoir considering waterflooding without (WF) and with ICV (WF+ICV) as production strategies. A complete methodology is applied to select and compare the strategies by optimizing the design and control variables through model-based reservoir simulation, using the Net Present Value (NPV) as the objective function (OF). The study case is named EPIC001, which has a 13 API heavy oil reservoir and is part of a Brazilian offshore field.The results showed that WF+ICV is more feasible for our case than WF and obtained a larger NPV. The installation and control of ICVs allowed the reservoir to have a better field performance and demonstrated the value of ICV by producing more oil with less production and injection of water, while maintaining the reservoir pressure.Our methodology worked adequately to optimize WF and WF+ICV for a heavy oil reservoir considering a nominal case (base case, step 6 from 12 steps proposed by SCHIOZER et al., 2019). Consequently, a decision-maker or a researcher could use this procedure for similar cases to optimize, compare, and select production strategies.

Keywords: intelligent wells, Waterflooding, heavy oil reservoir, Production Strategy Optimization, model-based field development and management, reservoir simulation.