OTC 21985--Optimization of the Net Present Value of Carbon Dioxide Sequestration and Enhanced Oil Recovery

摘要

Sequestration of carbon dioxide (CO_2) in depleted or partially depleted oil reservoirs is an immediate, cost-effective option to reduce CO_2 emissions into the atmosphere. Carbon dioxide has been injected into oil reservoirs for the purpose of enhancing oil recovery (EOR). With EOR, the goal is to maximize the oil production by minimizing the use of CO_2 while with sequestration, the goal is to maximize the storage of the CO_2. During EOR, a significant amount of CO_2 may be sequestered in the reservoir. If CO_2 emissions are regulated, the EOR process may therefore be able to earn sequestration credits in addition to oil revenues. We develop a theoretical framework that analyzes the co-optimization of oil extraction and CO_2 sequestration. The economic analysis takes into account factors such as capture, transportation and recycling costs. This paper discusses the effects of several injection strategies and injection timing on optimization of oil recovery - CO_2 storage capacity for a synthetic, three dimensional, heterogeneous reservoir model. A simulation study is completed using a 3-D compositional simulator “ECLIPSE 300” and an optimization algorithm in order to optimize the net present value of oil recovery and CO_2 storage. A number of simulations are studied to achieve comprehensive understanding of the financial performance of coupled CO_2 sequestration and EOR projects. The simulations have showed that the projects would be unprofitable for immiscible cases when using costs typical of current CO_2 capture from power plants unless there is some form of credit for storage. In contrast, in miscible cases, the projects may be profitable even without considering any CO_2 credits and their profitability is further enhanced with possible carbon credits. The results show that innovative reservoir engineering techniques are required for co-optimizing CO_2 storage and oil recovery.