TY - THES

T1 - Modelling of Imbibition Processes Including Alkali-Polymer EOR

AU - Mukhametshina, Leisan

N1 - embargoed until null

PY - 2020

Y1 - 2020

N2 - The thesis provides a simulation model for a spontaneous imbibition process on a sandstone plug sample with different chemical solutions, including alkali/polymer EOR. The input data, e.g. porosity, absolute permeability, fluid saturations, density and viscosity of fluids, are taken from laboratory experiments performed by OMV Upstream. The model was built using tNavigator [version 19.4], which is an integrated static and dynamic modelling tool. A spontaneous imbibition experiment with an Amott cell was used as a base for the structure and the shape of the model. Two main regions were defined in the model: the rock saturated by oil and water, and the Amott cell itself containing the displacing fluid (water or the chemical solution). Spontaneous imbibition laboratory experiments were conducted upfront with prepared test water, alkali, polymer and alkali-polymer solutions. The results of those experiments were used to history match the simulation model. The oil production is mostly affected by the capillary pressure and relative permeability curves for the water-oil case, and also the capillary desaturation curve (CDC) for the chemical cases. These three major parameters were unknown before the creation of the simulation model. Therefore, they were used as variables in the history match of the model. In the first part of the work, a simulation of the base experiment with test-water was done. The impact of both capillary and gravitational forces was investigated. The relationship of these forces was controlled by the vertical to horizontal permeability ratio (kv/kh). In the second part of the thesis, the models for alkali and alkali-polymer experiments were simulated. The reduction of interfacial tension (IFT) caused by alkali decreases the capillary pressure. IFT was used as one of parameters for the history matching. In the previously performed laboratory experiment, wettability alteration was studied using aged and non-aged core plugs. However, within this thesis, only the modelling of the water-wet sample was performed. Hence, the influence of alkali on wettability change is out of the scope of the thesis. The provided simulation model helps understand the physical processes that are taking place during spontaneous imbibition and gives a visualization of the saturation profile in the core. However, the models did not completely match the oil production in the laboratory experiments. The results of this work can be used to reduce the uncertainty in the IFT, and capillary desaturation curves used to forecast the incremental recovery from chemical EOR.

AB - The thesis provides a simulation model for a spontaneous imbibition process on a sandstone plug sample with different chemical solutions, including alkali/polymer EOR. The input data, e.g. porosity, absolute permeability, fluid saturations, density and viscosity of fluids, are taken from laboratory experiments performed by OMV Upstream. The model was built using tNavigator [version 19.4], which is an integrated static and dynamic modelling tool. A spontaneous imbibition experiment with an Amott cell was used as a base for the structure and the shape of the model. Two main regions were defined in the model: the rock saturated by oil and water, and the Amott cell itself containing the displacing fluid (water or the chemical solution). Spontaneous imbibition laboratory experiments were conducted upfront with prepared test water, alkali, polymer and alkali-polymer solutions. The results of those experiments were used to history match the simulation model. The oil production is mostly affected by the capillary pressure and relative permeability curves for the water-oil case, and also the capillary desaturation curve (CDC) for the chemical cases. These three major parameters were unknown before the creation of the simulation model. Therefore, they were used as variables in the history match of the model. In the first part of the work, a simulation of the base experiment with test-water was done. The impact of both capillary and gravitational forces was investigated. The relationship of these forces was controlled by the vertical to horizontal permeability ratio (kv/kh). In the second part of the thesis, the models for alkali and alkali-polymer experiments were simulated. The reduction of interfacial tension (IFT) caused by alkali decreases the capillary pressure. IFT was used as one of parameters for the history matching. In the previously performed laboratory experiment, wettability alteration was studied using aged and non-aged core plugs. However, within this thesis, only the modelling of the water-wet sample was performed. Hence, the influence of alkali on wettability change is out of the scope of the thesis. The provided simulation model helps understand the physical processes that are taking place during spontaneous imbibition and gives a visualization of the saturation profile in the core. However, the models did not completely match the oil production in the laboratory experiments. The results of this work can be used to reduce the uncertainty in the IFT, and capillary desaturation curves used to forecast the incremental recovery from chemical EOR.

KW - spontaneous imbibition

KW - Amott cell

KW - modelling

KW - alkali

KW - EOR

KW - spontaneous imbibition

KW - Amott cell

KW - modelling

KW - alkali

KW - EOR

M3 - Master's Thesis

ER -