First Low-Carbon Geopolymer-Based Cement-Free Primary Wellbore Isolation in an Offshore Location: A Case Study from Qatar

A pivotal advancement in the decarbonization of well cementing operations is the replacement of conventional Portland cement with a geopolymer-based, cement-free system. The production of one metric ton of Portland cement results in the emission of approximately one metric ton of CO2, driving the need for sustainable alternatives in wellbore isolation. To address this, a geopolymer cement-free system, specifically engineered to withstand downhole temperature and pressure conditions, was successfully deployed in Qatar. This case study details the first large-scale implementation of this low-carbon technology in Middle East Offshore location, marking a milestone in sustainable well construction. The geopolymer cement-free system utilizes aluminosilicate precursors activated in an alkaline medium to form a chemically bonded matrix with mechanical properties comparable to, or exceeding, those of conventional cement. This system provides a technically viable and environmentally sustainable alternative for primary cementing applications while aligning with global decarbonization objectives. A key consideration in the deployment of this system was the integration of locally sourced raw materials to minimize emissions associated with material transportation. Extensive evaluations of various Qatari aluminosilicate sources were conducted, leading to the selection of a suitable material that met stringent performance criteria for wellbore integrity. Comprehensive laboratory testing, including rheology, mechanical, and durability assessments, was conducted under simulated well conditions to ensure the robustness of the geopolymer slurry. These tests encompassed full sensitivity analyses to optimize the formulation for the target well. Field deployment confirmed that the low-carbon geopolymer cement-free system seamlessly integrates into conventional oilfield cementing workflows without necessitating modifications to well design methodologies, onsite execution protocols, or post-job evaluation techniques. The products were needed to send to offshore location by offshore vessel. Critical steps have to be taken into consideration of transportation of the products eliminating the chance of getting contamination during transportation The successful application of this novel cement-free system, utilizing indigenous Qatari raw materials, represents a significant step in the transition toward sustainable well construction practices in Qatar and the broader Middle East region. A detailed methodology encompassing planning, execution, and performance evaluation of the cementing operation. The success of this initiative was driven by close collaboration between the operator and the cementing service provider. Critical aspects such as fluid formulation, computational simulations, laboratory testing, operational execution, and post-job evaluation are systematically analyzed within this paper. Prior to field deployment, a comprehensive yard test was conducted to validate bulk material handling, pneumatic transfer, and mixing performance using a conventional high-pressure cementing unit. Additionally, a sustainability assessment based on life-cycle analysis was performed to quantify the reduction in carbon footprint associated with the adoption of this geopolymer cement-free system in Offshore Environment.