Chemical Enhanced Oil Recovery

Kishore Mohanty

Matthew Balhoff

Nicolas Espinoza

Larry Lake

Quoc Nguyen

Ryosuke Okuno

Gary Pope

Wen Song

Description

Goal: To conduct research to improve displacement efficiency, sweep efficiency, and scale-up by cost effective chemical enhanced oil recovery processes.

The Chemical Enhanced Oil Recovery Research Project includes experimental and modeling research on all chemical EOR methods including polymer flooding, surfactant flooding, alkaline-surfactant-polymer flooding, low tension gas flooding, wettability alteration, mobility control using foam, low salinity water flooding, shale stimulation and hybrid chemical-thermal methods by a team (of more than 30) faculty members, senior research scientists, research associates, post docs, graduate students and undergraduate students. Major advances in chemical EOR have greatly extended the range of reservoir conditions and types, reduced the cost of recovering the oil and increased the process robustness. Entirely new classes of superior surfactants have been developed as part of this research project and are now being deployed in numerous field projects. New capabilities have been added to the UTCHEM simulator and engineers worldwide are using UTCHEM to simulate and optimize field-scale chemical floods.

Faculty Supervisors

Directors: Kishore Mohanty and Matthew Balhoff

Additional PIs: Nicolas Espinoza, Larry Lake, Quoc Nguyen, Ryosuke Okuno, Gary Pope, Wen Song

Research Staff

Gayan Abeykoon, Almas Aitkulov, Francisco Arguelles. Xiongyu Chen, Alolika Das , Saroj Ghimire, Haishan Luo, Chammi Miller, Krishna Panthi, Fadi Shammas, Upali Weerasooriya, Chiyu Xie

Major Projects 

Reducing Surfactant Retention (PIs: Mohanty & Pope)

The goal is to reduce surfactant retention caused by adsorption and phase trapping. We have shown that if the micremulsion is Newtonian, the phase trapping is low. Surfactant formulations have been developed that reduce the surfactant retention in sandstones and carbonates.

shear rate chart

New Chemical Development (PI: Weerasooriya)

The goal of this project is to identify new, cost-effective surfactants and co-solvents that can give ultralow tension with reservoir oil and injected brine at the reservoir temperature and pressure. Many new surfactants and co-solvents developed during the past 10 years have extended the range of reservoir conditions to much higher temperature and salinity and reduced the chemical cost. The goal of this project is to identify new, cost-effective surfactants and co-solvents that can give ultralow tension with reservoir oil and injected brine at the reservoir temperature and pressure. Many new surfactants and co-solvents developed during the past 10 years have extended the range of reservoir conditions to much higher temperature and salinity and reduced the chemical cost.

chemical chart

Alternate Alkali Development (PIs: Mohanty & Pope)

The goal of this project is to develop alkalis other than sodium carbonate for ASP formulations. If the reservoir has gypsum or anhydrite, than sodium carbonate cannot be used as the alkali because it causes precipitation. We are studying other alkalis such as sodium metaborate, sodium hydroxide and ammonia. These alkalis affect brine composition, geochemical interactions as well as the phase behavior.

salinity chart

Surfactant Imbibition in Fractured Reservoirs (PIs: Pope, Balhoff & Mohanty)

The goal of this project is to improve oil recovery in fractured carbonate and shale reservoirs. Carbonate reservoirs tend to be oil-wet/mixed-wet. Water flooding does not recover much oil from the matrix. Surfactants can be used to improve oil recovery by lowering interfacial tension, altering wettability towards water-wet and increasing pressure gradient in the fracture. Both static and dynamic imbibition tests are being conducted to improve oil recovery. In shale reservoirs, oil flow from the matrix is often restricted due to low oil permeability and oil-wettability. Surfactant treatments can alter wettability. Surfactants are being tested to alter the wettability of shales at high temperature and salinity.

produced oil solubilized as emulsion

Mechanisms of Low Salinity Waterflooding (PIs: Mohanty & Song)

The goal of this project is to identify the mechanisms of low salinity or modified salinity water flooding. Experiments are being conducted in reservoir as well as outcrop rocks and effluent ion compositions are being studied. Mechanistic models are being developed that can explain experimental observations.

Viscous Oil EOR (PI: Mohanty)

The goal of this project is to develop chemical methods to recover viscous oils. Alkali, polymer, alkali-cosolvent-polymer, and alkali-surfactant-polymer methods are being tested. A two-dimensional flow cell is used to evaluate the sweep efficiency.

viscous oil

Role of Viscoelasticity in Polymer Flooding (PIs: Balhoff, Mohanty & Pope)

Polymers are supposed to viscosify water and improve sweep efficiency. It has been observed that some polymers do also improve microscopic displacement efficiency, perhaps due to viscoelasticity. The goal of this research is study how viscoelasticity can improve displacement efficiency. Polymer stability is also being studied at high temperature-high salinity conditions.

LB simulation of droplet oscillation by viscoelastic fluid 

(a) Displacement y Newtoninan Fluid

viscoelasticity colorful abstract

(b) Displacement by Viscoelastic Fluid

image004

(c) Viscoelastic turbulence

Polymer Injectivity in Wellbores (PIs: Espinosa & Balhoff)

The goal of this work is to couple geomechanics around the wellbore to polymer rheology to estimate the true polymer injectivity in wellbores. DEM-CFD models are being developed. Equivalent skin factors will be calculated and integrated into UTCHEM.

polymer injectivity

Low Tension Gas Flooding (PI: Nguyen)

The goal of this work is to study low tension gas flooding. Polymer is used in ASP floods to provide mobility control. Under certain conditions (e.g. high temperature) polymers cannot be used. Foams can be used instead to provide mobility control to surfactant floods. Experiments and modeling are being conducted to understand this process.

low tension gas flooding

Numerical Simulation of Chemical Floods (PIs: Mohanty & Pope)

The goal of this work is to incorporate the mechanisms observed in laboratory into a mechanistic simulator UTCHEM that can be used at the field-scale. Simple and detailed phase behavior, polymer transport, viscous fingering, low tension gas models are being incorporated. Results of these simulations are being compared with experimental data to calibrate the models.

chemical flooding chart

Chemical Stimulation of Shales (PI: Mohanty)

The goal is to develop surfactant-based stimulation chemicals to improve production rate from shale wells. The mechanisms being studied are wettability alteration, reduction in interfacial tension and removal of asphaltene/organic residue from the matrix in the vicinity of fractures.

chemical stiumulation of shales

Improved SAGD & CSS with Alkaline Solvents (PI: Okuno)

The goal of the project is to reduce the temperature of thermal operations by improving the oil-phase mobility by IFT reduction, dilution of oil and de-emulsification of water-in-oil emulsion. It would reduce heat loss and steam requirement.

horizontal well and oil shale

Member Companies

Subsurface Applications 

  • Conventional oil and gas
  • Tight and shale oil and gas
  • Heavy-oil/bitumen/tarmat

Technical Disciplines

  • Production Engineering
  • Reservoir Engineering
  • Petrophysics/Formation Evaluation
  • Data Analytics and Machine Learning
  • Geomechanics/Rock Mechanics
  • Geology
  • Geophysics/Seismic Interpretation
  • Geochemistry
  • Geostatistics
  • Computational Sciences

Engineering Tools 

  • Large Scale Simulation 
  • Pore-scale simulation 
  • Analytical models
  • Macro-scale experiments 
  • Micro-scale experiments 
  • Fluid analysis 
  • Software Development / Deployment 
  • Design of Experiments / Uncertainty Quantification