Chemical Enhanced Oil Recovery

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.

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.

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.

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.

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.

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.

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

(b) Displacement by Viscoelastic Fluid

(c) Viscoelastic turbulence

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.

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.

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.

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.

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.