Optimized Reduced-Portland Cement System for Lowering Carbon Emissions in Well Cementing Operations

Unofficial AI-generated summary based on the public title and abstract. Not an official translation.

🔬研究者:Provides field-validated data on SCM substitution in cementing, useful for further research on low-carbon cement formulations.

🏢実務担当者:Offers a proven method to reduce carbon footprint in well cementing operations while maintaining performance, applicable to similar projects.

🏛政策担当者:Demonstrates a practical, cost-effective emission reduction strategy in a hard-to-abate sector, informing policy on industrial decarbonization.

Abstract The design, laboratory evaluation, and field implementation of a reduced-Portland cement slurry system for surface and intermediate casing applications is presented. In this study, a portion of Portland cement was replaced with supplementary cementitious materials (SCMs) to lower the carbon footprint while maintaining critical performance parameters. The optimized formulation demonstrated stable rheology, controlled thickening time, adequate compressive strength, and effective zonal isolation in a broad density range. The system was developed for a large-scale drilling project in Oman and used locally manufactured cement with an in-house blending capability. Laboratory testing showed rheology, thickening time, stability, and compressive strength comparable to legacy Portland cement systems. Pilot testing confirmed mixability, pumpability, and consistency. The optimized blend was prepared at the in-country bulk plant and deployed using standard slurry mixing and pumping equipment. Comparison with Class G cement slurries confirmed equivalent strength and placement behavior. These results confirm that partial substitution of Portland cement with SCMs provided equivalent compressive strength and fluid properties and established the technical feasibility of reduced-Portland cement systems for well construction. Laboratory testing established the optimal cement-to-SCM ratios for the reduced-Portland designs for a 13 3/8-in. surface casing (17.2 kPa/m or 14.6 lbm/gal) and 9 5/8-in. intermediate casing (13.8 kPa/m or 11.7 lbm/gal). Subsequent slurry development testing verified that reduced-Portland slurry designs provide stable rheology, adequate thickening time, and compressive strength values that exceed 1,400 psi for surface casing designs and 500 psi for low-density intermediate casing designs. Laboratory results indicate no adverse impact on hydration or structural integrity because of SCM substitution and confirm early compressive strength development. Field mixing achieved accurate density control (±0.05 lbm/gal of design density) and smooth execution with no operational issues. Substitution of 37% of Portland cement with SCMs reduced carbon dioxide (CO2) emissions by approximately 130 tons per month and improved material efficiency, with full retention of technical performance and measurable environmental and resource efficiency benefits. This work demonstrates a field-validated pathway to lower-carbon cementing using readily available materials and established infrastructure. The system achieves measurable emission reductions, operational resilience, and cost efficiency without any loss of well integrity. The approach provides a scalable and practical transition toward sustainable well construction and represents a novel integration of SCM-based cement design into routine oilfield operations in Oman.

• crossref https://doi.org/10.2118/232546-msfirst seen 2026-05-18 05:32:00 · last seen 2026-05-31 05:00:18