Induced migration of fines during waterflooding in communicating layer-cake reservoirs

The effects of fines migration induced by injection of water with a different salinity than the reservoir brine are incorporated into the upscaling model for waterflooding in a layer cake reservoir with good communication between the layers. Mobilization and re-capturing of the reservoir fines may give rise to reduction of the permeability in water swept zones, which subsequently leads to the diversion of water flow from the initially more permeable layers to the less permeable ones. As a result, the displacement is more even, the water cut at the producer is decreased, and the oil recovery is increased. On the other hand, more energy for the pressure drop is required to maintain a constant flow rate. These effects are studied within a new upscaling model developed previously (Zhang et al., 2011). In a communicating layer cake reservoir, higher end-point mobility ratio (water to oil) leads to more crossflow between layers and lowers the water sweep efficiency. However, this ratio facilitates the fluid diversion caused by the fines migration, leading to a more efficient enhanced oil recovery. The positive contribution from the mobility ratio to the increased oil recovery due to fines migration seems to be limited

Effects Of Induced Migration Of Fines On Water Cut During Waterflooding

139239-MSPermeability decline during corefloods with varying water composition, especially with low salinity water, has been widely reported in the literature. It has often been explained by the lifting, migration and subsequent plugging of pores by fine particles, which has been observed in numerous core flood tests with altered water composition. This effect can be considered to provide a relatively simple method for mobility control during waterflooding. In previous research, the Dietz model for waterflooding in a layer-cake reservoir with a constant injection and production rate was combined with a particle detachment model to investigate the effect of fines migration and induced permeability decline on reservoir sweep efficiency. In this work, the analytical model was extended to waterflooding with a given pressure drop between injection and production wells. The modelling showed that permeability decline in the water swept zone, caused by the alteration of the injected water composition and induced fines migration, may be able to improve waterflood performance by delaying water breakthrough and reducing the water cut at producing wells.Abbas Zeinijahromi, Phillip Lemon, Pavel Bedrikovetsk

Productivity impairment of gas wells due to fines migration

Document ID: 151774-MSAbstract Well productivity decline have been widely observed for gas wells producing the reservoir fines. The phenomenon has been explained by the lifting, migration and subsequent plugging of the pores by the fine particles, finally resulting in permeability decrease. It has been observed in numerous core flood tests and field cases. The new basic equations for the detachment of fine particles, their migration and size exclusion, causing the rock permeability decline during gas production, have been derived. The analytical model, developed for the regime of steady state gas production with a gradual accumulation of strained particles, exhibits the linear skin factor growth vs the amount of produced reservoir fines. The modeling results are in a good agreement with the well production history. The model predicts well productivity decline due to fines production based on the short term production data.A. Zeinijahromi, A. Vaz, P. Bedrikovetsk

Mathematical model for fines-migration-assisted waterflooding with induced formation damage

Permeability decline during corefloods with varying water composition, especially with low-salinity water, has been widely reported in the literature. This effect can provide a relatively simple method for mobility control during waterflooding. In this work, new basic equations for waterflooding with salinity variations causing the detachment of fine particles, their migration, and their straining are derived. The maximum concentration of attached fine particles as a function of water salinity and saturation is used to model the fines detachment. In large-scale approximation, the equivalence between the model for two-phase flow with fines migration and the adsorption-free polymer-flood model is established, which allows applying a commercial polymer flood simulator for modeling the waterflood with induced fines migration. The modeling showed that the permeability decline in the water-swept zone, caused by the alteration of the injected water composition and induced fines migration, may be able to improve waterflood performance by delaying water breakthrough, increasing sweep efficiency, and reducing the water cut, thus providing a relatively simple method for mobility control during waterflooding. Copyright © 2013 Society of Petroleum Engineers.Abbas Zeinijahromi, Thi Kim Phuong Nguyen and Pavel Bedrikovetsk

Well impairment by fines migration in gas fields

Well productivity decline has been widely observed for gas wells producing reservoir fines. The phenomenon has been explained by lifting, migration and subsequent plugging of the pores by the fine particles, finally resulting in permeability decrease. It has been observed in numerous core flood tests and field cases. The new basic equations for the detachment of fine particles, their migration and size exclusion, causing the rock permeability decline during gas production, have been derived. The analytical model developed for the regime of steady state gas production with a gradual accumulation of strained particles, exhibits linear skin factor growth versus the amount of produced reservoir fines. The modelling results are in a good agreement with the well production history. © 2012 Elsevier B.V.Abbas Zeinijahromi, Alexandre Vaz, Pavel Bedrikovetsk

Axi-symmetric two-phase suspension-colloidal flow in porous media during water injection

Injection of colloids and suspensions in natural reservoirs with particle capture results in well injectivity decline. However, some initial improvement in injectivity was observed during waterflooding of oilfields and explained by increasing mobility of two-phase fluid during the displacement of more viscous oil by water. We derive an analytical model for axi-symmetric two-phase flow with simultaneous deep bed filtration of injected particles, formation of external filter cake, and its stabilization due to particle dislodgement. The explicit formula for dimensionless pressure drawdown (impedance) yields the type curve for impedance history. It is shown that the initial injectivity increase, induced by varying two-phase mobility, adds three degrees of freedom to one-phase impedance growth model. This additional information is used for tuning the models with the Corey relative permeability and the pseudo-relative permeability under the viscous-dominant displacement. Treatment of the data from three synthetic cases results in good agreement with the initial data, validating the developed model adjustment method. Three field case data have been considered. Good agreement between the field and modeling data along with common values of the obtained constants validate the developed analytical model for injectivity decline during waterflooding and its adjustment method.Azim Kalantariasl, Abbas Zeinijahromi and Pavel Bedrikovetsk

Water-cut reduction during waterflood by induced fines migration: effects of varying formation damage coefficient

Decline of permeability during corefloods with low salinity and high pH water, has been widely reported in the literature. It has been explained by the lifting, migration and subsequent plugging of pores by fine particles, which has been observed in numerous core flood tests with altered water composition. This effect can be considered to provide a relatively simple method for mobility control during waterflooding. In previous research, the Dietz model for waterflooding in a layer-cake reservoir was combined with a particle detachment model to investigate the effect of fines migration and induced permeability decline on reservoir sweep efficiency and amount of injected water; the model was derived under the assumption of constant formation damage coefficient. In this work, the model was extended to the case where the formation damage, caused by captured fines, depends on absolute permeability of the rock. The modeling showed that the incremental recovery and reduced water cut, caused by induced fines migration, is lower for the case of formation damage coefficient decreasing with permeability increase, than for the case of constant formation damage coefficient.Abbas Zeinijahromi, Phillip Lemon and Pavel Bedrikovetsk

Taking advantage of fines migration formation damage for enhanced gas recovery

Abstract The core permeability decline during corefloods with varying water composition, especially with low salinity water, has been widely reported in the literature. It has often been explained by the lifting, migration and subsequent plugging of pore throats by fine particles, which has been observed in numerous coreflood tests with altered water composition. In this work, the concept of using this permeability decline in order to decrease water production during pressuredepletion in gas field is investigated. The small volume injection of fresh water into an abandoned watered-up well in order to slow down the encroaching aquifer water is discussed. Equations for two-phase immiscible compressible flow with fines migration and capture have been derived. In large scale approximation, the equations are transformed to the black-oil polymer flooding model. The performed reservoir simulation shows that injection of fresh water bank significantly decreases water production and improves gas recovery.P.T. Nguyen, A. Zeinijahromi, P. Bedrikovetsk

Fines-migration-assisted improved gas recovery during gas field depletion

The core permeability decline during corefloods with varying water composition, especially with low salinity water, has been widely reported in the literature. It has often been explained by the lifting, migration and subsequent plugging of pore throats by fine particles, which has been observed in numerous core flood tests with altered water composition. In this work, the concept of using this permeability decline in order to decrease water production during pressure depletion in gas field is investigated. The small volume injection of fresh water into an abandoned watered-up well in order to slow down the encroaching aquifer water is discussed. Equations for two-phase immiscible compressible flow with fines migration and capture have been derived. In large scale approximation, the equations are transformed to the black-oil polymer flooding model. The performed reservoir simulation shows that injection of fresh water bank significantly decreases water production and improves gas recovery. © 2013 Elsevier B.V.Thi K. Phuong Nguyen, Abbas Zeinijahromi, Pavel Bedrikovetsk

Effects of induced fines migration on water cut during waterflooding

Permeability decline during corefloods with varying water composition, especially with low salinity water, has been widely reported in the literature. It has often been explained by the lifting, migration and subsequent plugging of pores by fine particles, which has been observed in numerous core flood tests with altered water composition (salinity, pH) and temperature. This effect can be considered to provide a relatively simple method for mobility control during waterflooding. In previous research, the Dietz model for waterflooding in a layer-cake reservoir with a constant injection and production rate was combined with a particle detachment model to investigate the effect of fines migration and induced permeability decline on reservoir sweep efficiency. In this work, the analytical model was extended to waterflooding with a given pressure drop between injection and production wells. The modelling showed that permeability decline in the water swept zone, caused by the alteration of the injected water composition and induced fines migration, may be able to improve waterflood performance by delaying water breakthrough and reducing the water cut. © 2011 Elsevier B.V.Abbas Zeinijahromi, Phillip Lemon and Pavel Bedrikovetskyhttp://www.journals.elsevier.com/journal-of-petroleum-science-and-engineering