Innovative Low Co2 Cement, Tailored for Performance in Deep Water Wells, Harsh Chemical Environment and CCS

Microfine cement is used in the oilfield industry for their ability to seal low permeability rocks and fissures, as well as for their enhanced cementitious performance. In this paper, we present the use of Fine Cement blends with a high amount of inert material and environmentally friendly chemicals, allowing for a low CO2 footprint, high chemical and mechanical resistance in low density slurries for deep water application and improved zonal isolation and alleviate logistics using a single blend system. The new cement blend is obviously usable for other cementing applications. This study focuses on a system of a new microfine cement slurry incorporating micro silica, microfine cement, inert materials, and renewable and environmentally friendly chemicals. A typical 1.60 SG cement slurry was prepared using the API/ISO standard mixing protocol and tested using a viscometer, fluid loss, HPHT consistometer, ultrasonic cement analyzer, curing chamber and compression testing machine. Evaluations were conducted at low temperature (25 -30°C). The results from laboratory analyses are presented. The new cement system demonstrates an overall lower CO2 footprint, being three times lower than that of conventional Portland cement. The proposed system shows high early compressive strength (above 1000 psi) after 12 hours at sea bad temperature, and low permeability and set cement porosity. Furthermore, the scope of the tests aimed to develop a deepwater system that is eco-friendly and cost-effective, with the capability to significantly reduce operational costs. The combination of microfine cement, pozzolanic micro silica, inert materials, and environmentally friendly renewable chemicals results in a tight cement system that is well-suited for harsh chemical environments such as sour gas and CCS wells. Additionally, this new cement blend can be used in other renewable energy sectors such as geothermal, lithium extraction and hydrogen storage. This paper presents a new cement system with lower CO2e footprint compared to conventional Portland cement. The new cement designed with extremely low Portland cement content is suitable for primary and remedial cementing operations and in particular plug and abandonment. The system exhibits very low permeability, which makes it more durable compared to conventional cement for harsh chemical environments such as sour gas and CCS wells.