Abstract
The growing energy demand forces oil producers to improve their recovery techniques. Polymer flooding is an effective EOR technique in accelerating oil production. Traditional partially hydrolyzed polyacrylamide (HPAM) faces limitations in displacing oil in harsh reservoir conditions. High temperature, high salinity, and high shear rates degrade the polymer’s viscosity and negatively impact its performance in displacing the oil.This research thesis aims to utilize the novel polymer known as surface active polymers (SAP) which is derived from HPAM polymers; to understand SAP behavior and its characteristics in sandstone rocks. SAP has a feature of in-situ conformance control via shear thickening behavior and withstands the complexity of reservoir conditions. Haroun, et al., (2019) show that integrating SAP with the engineered brine has successfully increased displacement efficiency in sandstone rocks.
SAP will be used with the prepared engineered brine to test its efficiency in a selected RRT. Candidate’s Castle Gate outcrops will be used to test different polymer concentrations at highly saline formation brine and high temperature, in which this RRT, is characterized by high porosity and permeability range. This study aims to maximize the oil recovery, by selecting the optimum polymer concentration and optimum injection rate strategy based on conducting rheology, displacement efficiency, and NMR studies.
Understanding the viscoelastic behavior of SAP was accomplished by generating rheology maps by varying the polymer concentration, temperature, and shear rate. Then, polymer concentrations and different injection rate strategies were selected, which will help in achieving the targeted viscosity; to conduct several displacement efficiency tests. Whereas, NMR studies were performed pre- and post-polymer flooding which will reveal the effects of adsorption and retention of polymers as they flow through the porous media.
The results show that SAP was successfully able to create a relatively more controllable front in high porosity and permeability castle gate (CG) rocks; by progressively shear thickening followed by a progressive shear thinning of SAP by switching the injection rate with a total of 52.22% oil recovery. The success of this study will give a step of optimizing the concentration and shear rate strategy by referring to the rheology maps, which will help in achieving the targeted viscosity to create a more stable displacement front for a wide range of RRTs. Additionally, the obtained results reveal the findings and challenges of polymer flooding using SAP on high porosity and permeability CG sandstone, under harsh reservoir conditions.
Date of Award | 19 Jul 2024 |
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Original language | American English |
Supervisor | Mohamed Haroun (Supervisor) |
Keywords
- EOR
- SAP
- Shear thickening
- Shear thinning
- Displacement Efficiency