Sahana N. Annadorai, Ph.D

Registered Patent Agent

Sahana N. Annadorai, Ph.D

Registered Patent Agent

Practice Focus

Patent practice with emphasis on chemistry, chemical engineering, biochemistry and biotechnology.

Practice Description

Dr. Annadorai focuses on oil and gas chemistry, chemical engineering and related fields. Her work includes patent drafting, prosecution, prior art search, review, etc. She also has a broad understanding and experience in carbohydrate and fluorous phase chemistry including microarray and biphasic catalysis with perfluorinated compounds, and method development in chemical applications.

Dr. Annadorai’s expertise in oil and gas production chemicals include flow assurance chemicals like low dosage hydrate inhibitors (LDHIs), asphaltenes and scale inhibitors. She is co-inventor of a family of patented anti-agglomerants for hydrate inhibition, described in US 9,410,073, which is an industry-leading product for the Gulf of Mexico operations. She has also worked extensively on test method development for screening and testing production chemicals for oil and gas. Her paper linking surfactant behavior and hydrate inhibitor performance, published in the Journal of Chemical Engineering Data was a path breaking research on the topic and is highly cited in both fundamental hydrate research and technical application. She was also a key advisor on LDHI research trends and research pathways for Colorado School of Mines (CSM) Hydrate Research Center.

Dr. Annadorai serves as a Board member for Technology Collaboration Center (TCC) in Houston, bringing together diverse industries in Houston area to facilitate collaboration and resolve cross-industry challenges. She is the Chair of the Collaboration Committee for the TCC implementing collaboration strategies and spearheading alliances with key organizations.


United States Patent and Trademark Office Registration for Patent Agents (2021)

Professional Affiliations

  • American Intellectual Property Law Association (2021)
  • Houston Intellectual Property Law Association (2021)
  • Board of Directors, Technology Collaboration Center of Houston (2018)


  • B.S., St. Stephen’s College, Delhi, India (2004)
  • M.S., University of Delhi, India (2007)
  • Ph.D., Iowa State University, Ames, IA (2012)

Patent, Publication and Presentations

  • Nagappayya, S. K.; Bartels, J. W. “Old technology, new market- low dosage hydrate inhibitor in US Onshore.” Podium Presentation at 9th International Conference on Gas Hydrates (ICGH), Denver, Colorado, June 2017.
  • Webber, P. A.; Nagappayya, S. K. Anti-agglomerants for controlling hydrates. United States Patent No. US9,410,073 B2. Issued August 2016.
  • Nagappayya, S. K.; Lucente-Schultz, R. M.; Nace, M.; Ho, V. M. “Anti-agglomerant hydrate inhibitors: The link between hydrate-philic surfactant behavior and inhibition performance.” Journal of Chemical Engineering Data, 2015, 60(2), 351-355.
  • Nagappayya, S. K.; Pohl, N. L. B. “Production of fluorous-based microarrays with uncharged carbohydrates.” Methods in Molecular Biology, 2012, 808, 149-153, Humana Press, Springer Science, New York, NY (Invited book chapter)
  • Edwards, H. D.; Nagappayya, S. K.; Pohl, N. L. B. “Probing the limitations of fluorous content for tag-mediated microarray formation.” Chemical Communications, 2012, 48, 510 – 512.
  • Ph.D. Thesis Title: “Method development for the glycosylation and microarraying of L-rhamnose with applications toward the automated solution-phase synthesis of homogalacturonan and rhamnogalacturonan I.” 2012. Thesis Advisor: Prof. Nicola L. B. Pohl.
  • Nagappayya, S. K.; Pohl, N. L. B. “Di-fluorous tagging strategy for automated solution-phase synthesis of plant oligosaccharides.” Paper Presentation at ACS Annual Meeting, Division of Organic Chemistry, New Reactions and Methodologies Session, Boston, MA, August 2010.