Improved Multiphase Flow Performance Using Autonomous Inflow Control Valve and its Potential Impact on Reservoir Recovery

Typically oil fields leave half of the oil, that was originally in the reservoir, left after the production is closed. One of the challenges that contributes to the oil remaining is the production of unwanted fluids, such as water, steam and gas. The oil production and recovery can be improved by increasing the reservoir contact. Increased reservoir contact can be achieved by drilling long horizontal wells. Another method to improve oil recovery is implementing inflow control technologies. By balancing the pressure drop along the well, these technologies are able to reduce the production of unwanted fluids and increase the oil production. One of these inflow control technologies which has been deployed internationally during the last few years is the patented Autonomous Inflow Control Valve (AICV). AICV can control or even totally stop the production of unwanted fluids and increase the oil production. AICV installations worldwide have shown promising results in a wide range of reservoir conditions. However, further development of AICV to cover even wider ranges of applications and reservoir conditions, is the main objective of this PhD project. This will be achieved by performing experimental tests using realistic reservoir fluids, and doing simulations using industry standard reservoir simulator. Experimental results will provide information about the AICV performance for water, oil, gas, and steam. Also, the results will describe the choking ability of AICV when exposed to unwanted fluids. One example of AICV development prospects is AICV for CO2 Enhanced Oil Recovery (EOR) applications. AICV for CO2 EOR can contribute to choking back CO2 and avoiding reproduction of CO2 thus making possible to store CO2 in the oil reservoirs. Another application is AICV for Steam Assisted Gravity Drainage (SAGD) reservoirs. AICV for SAGD application can reduce energy consumption for steam generation and consequently improving the economics of SAGD projects. All the experiments and simulations demonstrate that the improved multiphase flow performance using AICV has a significant potential for increased oil production and recovery. The novelty of this work is the experimental data which demonstrate the unique behavior of AICV within multiphase flow. Furthermore, the experimental results are implemented in simulation tools, and new methods and workflows are developed in order to enable the modelling of advanced wells with AICVs under challenging reservoir conditions. The main contribution of this industrial PhD is to extend the insight in advanced well completion with AICVs at different reservoir conditions and various applications. This is achieved by improving the AICV design and performance, and by developing coupled well-reservoir models to investigate the impact of AICV on increased oil production and recovery. The outcome of this work can be utilized to address the challenges related to SAGD/CO2 EOR in oil reservoirs.

Performance curves for one and two-phases for orifice ICD and AICV were generated. This indicates that the gas reduction by using AICV is significant. Corresponding simulations were conducted in NETool, OLGA/ROCX, and CMG, and the results show that the steam reduction can be up to 64% and the oil increase can reach 15% for SAGD application. . In addition, a more uniform temperature distribution, and steam conformance are observed in the AICV cases. For CO2-EOR application, the results from the experiments show that AICV in comparison with ICD, reduces the water and CO2 volume flow rates by approximately 58% and 82%, respectively. The results obtained from the corresponding simulations for a case study show that the production of the mixture of water and CO2 is reduced by 20%. Choking back CO2 by using AICV may give a better distribution of CO2 in a larger area of the reservoir. This leads to a broader contact between CO2 and the residual oil in the reservoir, resulting in increased EOR. All the experiments and simulations demonstrate that the improved multiphase flow performance using AICV has a significant potential for increased oil production and recovery. The novelty of this work is the experimental data which demonstrate the unique behavior of AICV within multiphase flow. Furthermore, the experimental results are implemented in simulation tools, and new methods and workflows are developed in order to enable the modelling of advanced wells with AICVs under challenging reservoir conditions. The main contribution of this industrial PhD is to extend the insight in advanced well completion with AICVs at different reservoir conditions and various applications. This is achieved by improving the AICV design and performance, and by developing coupled well-reservoir models to investigate the impact of AICV on increased oil production and recovery. The outcome of this work can be utilized to address the challenges related to SAGD/CO2 EOR in oil reservoirs.

Early water and/or gas breakthrough is one of the main challenges in oil production which results into inefficient oil recovery. Existing mature wells must stop the production and shut down due to High GOR (gas oil ratio) and/or WC (Water Cut) although more oil still is remained in the reservoirs. In most fields more than 50% of oil at the Norwegian Continental Shelf will not be recovered. Inflow control technologies have been used widely during decades in order to make the wells more profitable by attaining uniform flow , delaying the unwanted fluid breakthrough and consequently maximizing the oil production and recovery. One of these inflow control technologies is patented Autonomous Inflow Control Valve (AICV) which can delay the onset of breakthrough and control or shut off completely the unwanted fluid production when the breakthrough occurs. Extensive amount of AICV development programs and several successfully performed qualification tests done at Equinor multiphase flow loop test facility have been resulted into a worldwide installations with significant well performance improvement. The current variant of AICV has been contributed in increased oil production, reduced water and/or gas production and generally making better and more profitable wells around the world. AICV technology has huge development potentials . This technology can be developed further for different type of reservoirs and applications such as light oil reservoirs, SAGD (Steam Assisted Gravity Drainage) applications or CO2-EOR (Enhanced Oil Recovery).