First Global Implementation of Geopolymer in Primary Casing Cementing

Abstract

Portland cements are integral components in the oilfield well construction process; however, the confluence of various business drivers have created the need to find sustainable alternatives materials. Geopolymers, already well known in traditional construction industries, show promise as alternatives to Portland cement in oilfield wells. Yet, successfully moving geopolymers from a concept in the laboratory to execution at the wellsite remains to be established. This paper presents evaluation of geopolymer cementing for use in oil and gas wells, specifically the primary cementing of liner strings in the Permian Basin. To evaluate geopolymer cementing for oil and gas well construction, a field example project was divided into four phases: development of robust slurry design in the laboratory, confirmation of compatibility with oilfield equipment, scalability for safe execution in the field, and validation through post-job evaluation techniques. The laboratory work included an engineered, innovative approach to chemistry to obtain a slurry matching and exceeding performance of Portland cement−based designs. Yard trials were performed to verify compatibility of geopolymers with industry-standard oilfield cementing equipment. The geopolymer-based designs were then scaled up to meet typical cementing job volumes and executed at the wellsite without deviating from conventional operating procedures. Post-job evaluation techniques to validate the placement included pressure matching and cement bond logs. Results have shown that for primary cementing applications, geopolymers can be an effective alternative to Portland cements. This case demonstrates that geopolymer cementing was able to fit into the oilfield cementing workflow without major changes to job design process, onsite execution, or post-job evaluation. Post-job pressure match of hydraulic simulations versus recorded pressure during job execution confirmed proper placement and conventional sonic and ultrasonic cement bond logging tools were able to confirm the presence of geopolymers within the wellbore providing further assurance. Introduction of geopolymer cementing requires the adaptation of innovative chemistry into the slurry design and consequently sourcing of materials typically not used in Portland cement blends. Additionally, attention to quality control of raw materials is required to ensure consistency of performance. Overall, geopolymer cementing can be successfully implemented into oilfield primary casing cementing applications using the existing infrastructure that has evolved from the historic use of Portland cement. Geopolymer cementing offers a unique opportunity for the oilfield industry to decrease CO2 emissions related to well construction and reduce dependence on the constrained supply of Portland cements. The case of cementing intermediate liner in the Permian Basin validates the scalability of the concept from inception in the laboratory to wellsite execution.