Dissertation Defense: Nora AlMaqseed

Dissertation Defense 

Nora AlMaqseed 

Peter Kitanidis (advisor), Scott Fendorf (co-advisor), Elliot White Jr (chair)

Friday, May 30th, 2025 Green 365, 10:00 AM (Pacific Time)

Deciphering Radioactivity in Kuwait Oilfields: Salt, Heat, and Reservoir Rock Interactions Promote Radium-226 Buildup

Oil production remains essential for global energy security yet poses hidden environmental risks, particularly in aging fields reliant on enhanced recovery. In Kuwait’s northern reservoirs, wells equipped with electrical submersible pumps (ESPs) have experienced persistent radioactivity since 2011, driven by heat-induced geochemical changes. This dissertation investigates the mechanisms by which elevated temperature gradients along ESP systems—and the associated downhole and surface piping—contribute to the formation and transport of radium-bearing scales, particularly in sandstone and carbonate reservoirs undergoing high-sulfate seawater injection.

We developed a mechanistic heat transfer model to resolve temperature profiles along the ESP assembly, enabling precise thermodynamic corrections to barite and Ra–Ba–Sr sulfate precipitation. Sample analyses using gamma spectroscopy, XRF, XRD, TEM, and EXAFS spectroscopy collectively confirmed the co-precipitation of radium-226 with barium and strontium sulfates. These scales, found on contaminated ESP components, present radiotoxicity risks through particle mobility and surface shedding—posing occupational hazards and long-term environmental liabilities. While oil remains indispensable for the coming decades, this work underscores the urgent need for safer, science-based production practices that protect human health and promote environmental justice for frontline workers.