Areal sweep efficiency improvement by integrating preformed particle gel and low salinity water flooding in fractured reservoirs

Fuel ◽  
2018 ◽  
Vol 221 ◽  
pp. 380-392 ◽  
Author(s):  
Ali K. Alhuraishawy ◽  
Xindi Sun ◽  
Baojun Bai ◽  
Mingzhen Wei ◽  
Abdulmohsin Imqam
Author(s):  
Imran Akbar ◽  
Zhou Hongtao ◽  
Liu Wei ◽  
Asadullah Memon ◽  
Ubedullah Ansari

: The Preformed Particle gels (PPGs) has been widely used and injected in low permeability rich oil zones as di-verting agent to solve the conformance issues, distract displacing fluid into out of sorts swept zones and reduce the perme-ability of thief zones and high permeability fractured zones. However, the PPG propagation and plugging mechanism is still remain unpredictable and sporadic in manifold void space passages. PPGs have two main abilities, first, it increases the sweep efficiency and second, it decreases the water production in mature oilfields. But the success or failure of PPG treatment largely depends on whether it efficiently decreases the permeability of the fluid paths to an expected target or not. In this study, the different factors were studied that affecting the performance of PPG in such reservoirs. PPGs were treated in different ways; treated with brine, low salinity, and high salinity brine and then their impacts were investigated in low/high permeability and fractured reservoirs and void space conduit models as well. From the literature, it was revealed that the sweep efficiency can be improved through PPG but not displacement efficiency and little impact of PPG were found on displacement efficiency. Similarly, on the other hand, Low salinity water flooding (LSWF) can increase the displacement efficiency but not sweep efficiency. Hence, based on above issues, few new techniques and directions were introduced in this work for better treatment of PPG to decrease water cut and increase oil recovery.


2020 ◽  
Vol 135 (1) ◽  
pp. 101-135
Author(s):  
Hasan Al-Ibadi ◽  
Karl D. Stephen ◽  
Eric J. Mackay

Abstract Chemical flooding has been implemented intensively for some years to enhance sweep efficiency in porous media. Low salinity water flooding (LSWF) is one such method that has become increasingly attractive. Historically, analytical solutions were developed for the flow equations for water flooding conditions, particularly for non-communicating strata. We extend these to chemical flooding, more generally, and in particular for LSWF where salinity is modeled as an active tracer and changes relative permeability. Dispersion affects the solutions, and we include this also. Using fractional flow theory, we derive a mathematical solution to the flow equations for a set of layers to predict fluid flow and solute transport. Analytical solutions tell us the location of the lead (formation) waterfront in each layer. We extend a correlation that we previously developed to predict the effects of numerical and physical dispersion. We used this correction to predict the location of the second waterfront in each layer which is induced by the chemical’s effect on mobility. We show that in multiple non-communicating layers, mass conservation can be used to deduce the interlayer relationships of the various fronts that form. This is based on similar analysis developed for water flooding although the calculations are more complex because of the development of multiple fronts. The result is a predictive tool that we compare to numerical simulations and the precision is very good. Layers with contrasting petrophysical properties and wettability are considered. We also investigate the relationship between the fractional flow, effective salinity range, salinity dispersion and salinity retardation. The recovery factor and vertical sweep efficiency are also very predictable. The work can also be applicable to other chemical EOR processes if they alter the fluid mobility. This includes polymer and surfactant flooding.


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