Chammi S. Miller

                  RESUME

Chammi S. Miller

Research Associate

Office Address  -  CPE 4.128

Email Address  - Chammi.miller@utexas.edu

Office Phone Number - 817-995-1097

Mobile Phone Number – 817-995-1097

LinkedIn URL  - https://www.linkedin.com/in/chammi-miller-phd-8525143/

 

RESEARCH HIGHLIGHT

Novel low salinity fluid systems for unconventional EOR

In shale wells production decline after first few years of production due to ultralow permeability, natural fractures and formation damage. In order to keep the sustainability of the production in the future we need to develop EOR techniques beneficial to future of the oil and gas industry in US. Our interest is to engineer low salinity formulations using green chemicals. These chemical formulations can be utilized as frac fluid or inject into adjacent wells as a water curtain for containment. Also during the huff-n-puff process these brine formulations can be used to pressurize the gas. Chemicals are selected based on reservoir matrix chemistry and oil chemistry. Selected chemical can increase stimulated reservoir volume by creating micro –factures in carbonate rich reservoirs, change the wettability of the fracture face, oxidize kerogen, and dissolve organic and clear the flow path. Also we are looking into use of produced water to design these formulations. In our studies we thoroughly evaluate chemistry of the matrix, formation brine and crude oil in order to customize the fluid systems. We evaluate phase behavior, wettability indexes, and spontaneous imbibition in low pressure and high pressure condition.   

RESEARCH PROJECTS

Project A. Engineered water for improved oil recovery

https://news.utexas.edu/2019/08/14/doe-grant-aims-to-improve-oil-recovery-by-using-engineered-water/

In this study we are focusing on tight fractured carbonate reservoirs. In general carbonates reservoirs tend to be oil-wet/mixed-wet due to positively charged mineral surfaces and negatively charged organic components in the crude oil. Secondary recovery by water injection alone does not work efficiently in oil-wet fractured reservoirs due to inefficient water imbibition into the matrix. Permeability of this reservoir is less than 30 mD therefore polymer injection also a not an option. The water composition can be engineered with dilution, ionic modification and surfactants. In this study we will modify produced water composition by dilution, adding ions and adding surfactants. The dilution effect on rock chemistry is evaluated by zeta potential measurements. The engineered water will be evaluated for enhanced oil recovery using contact angle screening, spontaneous imbibition and coreflood experiments.

Project B. Chemical blend for shale EOR

Shale oil production declines rapidly after the first year of production due to the low permeability of the shale matrix. Shale reservoirs have low porosity and extremely low permeability and a complex network of natural factures. In general, shale formations contain 3-10 wt% of organic material. Most of shale formations are mixed-wet and during the fracturing when water is injected some of the water remains in the matrix blocking the mobility of oil. We have developed novel fluid systems that can be utilized to rejuvenate old wells and improve the production. The fluid system is a chemical blend containing an organic solvent, an oxidizing agents, a weak acid and a surfactant. 

We also investigate application of chemical blend in CO2 huff-n-puff process. We have completed laboratory testing with different combinations with a great success. We are seeking for industry collaboration for a possible pilot test.

Project C.  Development of analytical evaluation techniques for subsurface research

We are interested in using fundamental chemistry for subsurface research. Currently we are evaluating usage of zeta potentials to understand brine-rock interactions with changing ion compositions. Also this technique can be extended to understand double layer behavior in the presence of oil residue, perhaps this could be a ground breaking technique to predict wettability altering chemical for EOR applications.

In past we optimized application of Thermal Gravimetric Analysis (TGA) combined with NMR to estimate initial liquids in shale matrix. We are exploring these techniques further in order to improve quantitative analysis of oil recovery in shale imbibition experiments. 

We are evolving non-traditional combine analytical techniques in our research using ion chromatography (IC), gas chromatography (GC), ESEM, NMR, UV-VIS, TGA, and other techniques.