Portland cement (the primary component in concrete) is the second most consumed product, globally, after water (Czigler 2020). With the sheer volume of cement that is produced each year, it should not be surprising that the manufacturing process ranks as the third largest industrial source of emissions and pollution in the world (EPA 2022). Specifically, cement plants emit a significant amount of carbon dioxide (CO2) through fuel consumption to generate heat and the unavoidable chemical process of calcination. An oilfield service company and a cement manufacturer partnered to propose and implement a reduced carbon cementing solution to a future-focused operator. The primary goals were to 1) create a cement which reduced CO2 emissions by 20-30%, and 2) replace previously used Class A slurries with Class L slurries, while maintaining or improving the cement performance properties.
A new class of cement, Class L, was approved by the American Petroleum Institute (API) in 2019. This composite well cement is produced by intergrinding Portland cement clinker with one or more forms of gypsum, pozzolanic material (i.e., fly ash, silica fume, and natural pozzolans), as well as particle suspension aids. The cement manufacturer began working to create a Class L cement that would meet the same performance requirements as Class A cement while targeting substantial CO2 emissions reduction. The oilfield service company worked with the cement manufacturer over the course of two years to refine the product and evaluate it for oilfield application. Cement lab testing including thickening time, compressive strength, free water, fluid loss, transition time, and rheology evaluations were conducted on both the base Class L cement and designed slurries. Class L cement slurries were first implemented for this Appalachian Basin operator in late September 2022 and have since been utilized on more than 200 casing strings as of July 2023 across multiple operators.
The cement manufacturer has reported a 23% reduction in CO2 emissions by switching to the production of Class L cement from Class A within the same facility. Lab generated performance data of the base Class L cement and corresponding slurries are very similar and, in some cases, better than the original Class A slurries. To-date, more than 100 jobs have been successfully executed for this operator using Class L cement slurries, delivering both zonal isolation and well-integrity.
As the oil and gas industry focuses more on our Environmental, Social and Governance (ESG) impact, the pathway that the cement manufacturer has paved is pivotal. Class L cement is a viable alternative to both API Class A and ASTM Type I/II cements utilized in well construction, while reducing CO2 emissions during manufacturing by 23%.
Kristin embarked on her professional journey in 2012, joining Halliburton as a field engineer specializing in cement. Over the years, she thrived in various technical advising and product management positions within the company, expanding her expertise to encompass all aspects of well construction, including wellbore logging. In early 2022, Kristin embraced a new challenge as a member of the business development team at Universal, where she focused on both frac and cement operations. Most recently, with the merger of equals between NexTier and Patterson-UTI, Kristin was promoted to the Director of Sales for the Northeast area of NexTier Completion Solutions, managing the sales team for all service lines.
Since 2015, she has been actively involved in the Pittsburgh Section of SPE, serving in several roles on the board of directors and even assuming the position of chairperson. In recognition of her outstanding service, she was honored with the Young Member Outstanding Service Award in 2018. Her contributions to the industry are evident through her authorship of multiple papers for the Society of Petroleum Engineers (SPE) and her recognition in the esteemed Journal of Petroleum Technology. At the 2023 SPE Eastern Regional Meeting, Kristin was presented the Public Service award for her continued dedication to SPE in various capacities. Committed to nurturing future talent, Kristin has been an industry advisory board member for Slippery Rock University's petroleum engineering program since 2019. Her dedication, advocacy, and expertise were further acknowledged when she assumed the role of Vice Chair of the Drilling, Completions, Well Facilities, and Production Committee with the Marcellus Shale Coalition in October 2022.
Kristin's educational background includes a Bachelor of Science degree in Chemical Engineering from the University of Pittsburgh, supplemented by minors in Petroleum Engineering and Chemistry. With a strong foundation and a wealth of experience, she continues to make significant contributions to the oil and gas industry.