Mobility Control Requirement in EOR Processes

2011 ◽  
pp. 79-100 ◽  
Author(s):  
James J. Sheng
Keyword(s):  
Mobility Control ◽  
Control Requirement ◽  
Eor Processes

A New Approach to Model Hysteresis and Its Impact on CO2-EOR Processes with Mobility Control Strategies

2013 ◽  
Author(s):  
Mohammad Reza Beygi ◽  
Mojdeh Delshad ◽  
Venkateswaran Sriram Pudugramam ◽  
Gary Arnold Pope ◽  
Mary F. Wheeler
Keyword(s):  
Control Strategies ◽  
Mobility Control ◽  
New Approach ◽  
Co2 Eor ◽  
Eor Processes

Enhanced Oil Recovery Pilot Testing Best Practices

2010 ◽  
Vol 13 (01) ◽  
pp. 143-154 ◽  
Author(s):  
G.F.. F. Teletzke ◽  
R.C.. C. Wattenbarger ◽  
J.R.. R. Wilkinson
Keyword(s):  
Best Practices ◽  
Enhanced Oil Recovery ◽  
Oil Recovery ◽  
Large Scale ◽  
Full Range ◽  
Mobility Control ◽  
Small Scale ◽  
Pilot Testing ◽  
Advantages And Disadvantages ◽  
Eor Processes

Summary Enhanced-oil-recovery (EOR) implementation is complex, and successful applications need to be tailored to each specific reservoir. Therefore, a systematic staged evaluation and development process is required to screen, evaluate, pilot test, and apply EOR processes for particular applications. Pilot testing can play a key role in this process. Before field testing, pilot objectives need to be clearly defined and well spacing, pattern configuration, and injectant volumes determined. This paper outlines a staged approach to EOR evaluation and focuses specifically on pilot testing best practices. These best practices were derived from ExxonMobil's extensive piloting experience, which includes more than 50 field pilot tests covering the full range of EOR processes. Topics covered include: (1) determining whether a pilot is needed and defining pilot objectives, (2) considerations for successful pilot design, (3) types of pilots and their advantages and disadvantages, (4) tools and techniques for assessment of key reservoir mechanisms, and (5) minimizing uncertainty in pilot interpretation. Key issues that are often addressed by pilots are discussed, including areal sweep and conformance, gravity override, viscous fingering, and loss of mobility control. Also included are aspects of instrumentation and measurements in pilot injection, production, and monitoring wells. Several ExxonMobil piloting examples are used to illustrate the best practices, including a single-well injectivity test, an unconfined pilot with observation wells, a small-scale confined pilot, and a large-scale multipattern pilot.

Gas-Injection Rate Needed for SAG Foam Processes To Overcome Gravity Override

SPE Journal ◽  
2014 ◽  
Vol 20 (01) ◽  
pp. 49-59 ◽  
Author(s):  
C.S.. S. Boeije ◽  
W.R.. R. Rossen
Keyword(s):  
Gas Injection ◽  
Injection Pressure ◽  
Leading Edge ◽  
Injection Rate ◽  
Mobility Control ◽  
Injection Well ◽  
Optimal Process ◽  
Severe Problem ◽  
Eor Processes ◽  
Strong Foam

Summary Gravity override is a severe problem in gas-injection enhanced-oil-recovery (EOR) processes, especially in relatively homogeneous formations. Foam can reduce gravity override. Shan and Rossen (2004) show that the best foam process for overcoming gravity override is one of injecting a large slug of surfactant followed by a large slug of gas, injected at constant, maximum-allowable injection pressure. This process works because foam collapses near the injection well, giving good injectivity simultaneously with mobility control at the leading edge of the gas bank. The supply of gas that would be needed to maintain constant injection pressure is a concern for EOR processes in which gas is produced industrially or from a separations plant with limited capacity: The available gas stream may not be sufficient for the optimal process. We show that for such a process, the pressure drop across the foam bank back to the injection well, at fixed injection rate, is nearly constant as the foam bank propagates radially outward. From this result, one can derive a simple formula to predict the rate of gas injection required for each of two limiting cases: An extremely strong foam at the foam front, many times more viscous than the fluids it displaces. In this case, the rate of gas injection required to maintain constant injection pressure is nearly constant, but injection rate is low. A foam just strong enough to maintain mobility control at its leading edge. In this case, injection rate required to maintain constant injection pressure increases steeply with time. Use of the formulae provides a quick initial estimate of how gas-injection rate must vary over the duration of the EOR process to maintain an optimal process. The fit to simulations of surfactant-alternating-gas (SAG) foam-injection rate in a five-spot pattern is remarkably good, especially for strong foam, given the simplicity of the model. In addition, we illustrate how one would determine the properties of a foam that would fit the available gas stream. This criterion then could guide the development of a surfactant formulation with these properties.

scholarly journals Experimental investigation of the displacement flow mechanism and oil recovery in primary polymer flood operations

2021 ◽  
Vol 3 (5) ◽  
Author(s):  
Ruissein Mahon ◽  
Gbenga Oluyemi ◽  
Babs Oyeneyin ◽  
Yakubu Balogun
Keyword(s):  
Relative Permeability ◽  
Oil Recovery ◽  
Polymer Flooding ◽  
Mobility Control ◽  
List Type ◽  
Motor Oil ◽  
Flow Mechanism ◽  
Fractional Flow ◽  
Recovery Method ◽  
Polymer Flood

Abstract Polymer flooding is a mature chemical enhanced oil recovery method employed in oilfields at pilot testing and field scales. Although results from these applications empirically demonstrate the higher displacement efficiency of polymer flooding over waterflooding operations, the fact remains that not all the oil will be recovered. Thus, continued research attention is needed to further understand the displacement flow mechanism of the immiscible process and the rock–fluid interaction propagated by the multiphase flow during polymer flooding operations. In this study, displacement sequence experiments were conducted to investigate the viscosifying effect of polymer solutions on oil recovery in sandpack systems. The history matching technique was employed to estimate relative permeability, fractional flow and saturation profile through the implementation of a Corey-type function. Experimental results showed that in the case of the motor oil being the displaced fluid, the XG 2500 ppm polymer achieved a 47.0% increase in oil recovery compared with the waterflood case, while the XG 1000 ppm polymer achieved a 38.6% increase in oil recovery compared with the waterflood case. Testing with the motor oil being the displaced fluid, the viscosity ratio was 136 for the waterflood case, 18 for the polymer flood case with XG 1000 ppm polymer and 9 for the polymer flood case with XG 2500 ppm polymer. Findings also revealed that for the waterflood cases, the porous media exhibited oil-wet characteristics, while the polymer flood cases demonstrated water-wet characteristics. This paper provides theoretical support for the application of polymer to improve oil recovery by providing insights into the mechanism behind oil displacement. Graphic abstract Highlights The difference in shape of relative permeability curves are indicative of the effect of mobility control of each polymer concentration. The water-oil systems exhibited oil-wet characteristics, while the polymer-oil systems demonstrated water-wet characteristics. A large contrast in displacing and displaced fluid viscosities led to viscous fingering and early water breakthrough.

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