Feasibility of sustainable recycling of drill cutting as additive in flexible base

The management of drill cuttings, a byproduct of oil and gas drilling, presents significant environmental challenges. In Texas, millions of cubic yards of drill cuttings have accumulated, raising concerns over long-term storage and disposal. At the same time, the state consumes approximately 3.7 million cubic yards of flexible base material annually for infrastructure projects. Incorporating drill cuttings into flexible base materials offers an opportunity to reduce waste, minimize environmental risks, and promote more sustainable construction practices. A practical framework for incorporating drill cuttings into flexible base applications is presented in Figure S- 1, integrating engineering, environmental, and economic assessments. Using drill cuttings from the Polk site as a case study, the research evaluates their properties, treatment methods, construction performance, and cost-effectiveness. Three treatment methods were investigated: lime, cement, and organoclay. Lime reduced plasticity and limited total petroleum hydrocarbon (TPH) mobility but had minimal effect on semi-volatile organic compounds (SVOCs) and increased trace metal leaching. Cement significantly improved compressive strength but had limited effect on TPH and SVOCs mobility. Its performance was reduced in the presence of hydrocarbons due to interference with cement hydration. Organoclay effectively reduced the leaching of TPH, SVOCs, and metals, with negligible impact on mechanical performance. Additionally, blending drill cuttings with appropriately selected aggregates helps meet flexible base specifications. Key performance criteria such as abrasion resistance, gradation, plasticity, and compressive strength are evaluated using standard tests, including the wet ball mill, particle size analysis, Atterberg limits, and Texas triaxial procedures. Overall, this study establishes a scalable and adaptable framework for the beneficial use of drill cuttings in infrastructure applications. Future research should refine treatment approaches, address site-specific contaminant variability, and explore broader engineering applications to maximize environmental and economic benefits. [Figure S- 1 included]

Name thesis:degree_name

Doctor of Philosophy

Discipline thesis:degree_discipline

Civil Engineering

Grantor

The University of Texas at Austin

Year dc:date.issued

2025

Author dc:creator

• Tung, Chih-Yu

Advisors dc:contributor.advisor

• El Mohtar, Chadi Said
• Gilbert, Robert B. (Robert Bruce), 1965-

Committee member dc:contributor.committeemember

• D. Nicolas Espinoza

• Flexible base
• Sustainable construction
• Treatment methods (lime, cement, organoclay)
• Drill cuttings
• Scalable framework

Identifier URI

https://doi.org/10.26153/tsw/61156

OAI identifier oai:identifier

oai:repositories.lib.utexas.edu:2152/133828