Abstract
Abstract
Enhanced oil recovery technique for carbonate or sandstone reservoirs using inflow control technology are often affected by undesired production of water and gas. Limited density and viscosity differences between oil, water and gas is often a challenge for most autonomous and passive inflow control technology due to limited fluids performance ratio between oil, water and gas when breakthrough happen. The fluid performance ratio describes how the ICD (Inflow Control Device) and AICD (Autonomous Inflow Control Device) preferably choke the unwanted fluid (water/gas) compared with oil.
Different ICD/AICD are utilizing both density and viscosity that effect the flow behavior difference in the valve to differentiate the pressure drop for oil, water, and gas. Different designs have been tested in single phase and multiphase full-scale flow loop testing that replicates downhole operating conditions. In order to understand the ICD/AICD behavior in reservoir environments for the duration life of the well, a wellbore model where the effect of fluids performance ratio is included. The model also includes the effect of mobility ratio and how this affects the importance of the fluid performance ratio.
Well completion has a critical role to optimize the well performance and enhanced oil recovery. In today’s engineer toolbox, a wide variety of inflow control technology completion options are available including various ICD and AICD. A new methodology and workflow have been developed to compared different type of inflow control technology completion to understand the capability to reduce unwanted water and gas production without needing detailed information about rock property variation along the wellbore in the reservoir. These methods are based on laboratory flow performance data from each device and will compare various downhole inflow control tools based on their fluid phase performance ratio to produce oil, choke water and/or gas and express the fluid preference by ratio in percentage.
Experimental flow loop results illustrate a significant different in fluids performance ratio of conventional ICD and AICV. AICD with dynamic flow area are choking water breakthrough more effectively, resulting in better sweep along the wellbore section that were not previously being produced. By limiting the water and gas production operators are therefore able to apply higher drawdown to increase oil recovery significantly. This improves the economics of thin-oil rim development and benefits of reduced environmental impact per oil produced due to less un-needed water and gas being produced to surface.