The use of superplasticizer for concentrated slurry density control

Abstract

 Given the constant development of the oil and gas industry and increasing requirements for well drilling efficiency, the study of concentrated slurry density control is critical to ensure drilling processes’ safety and stability and prevent adverse environmental impacts. The study aims to investigate the possibility of using an additive to pure Portland cemented slurry to form high-density concentrated slurry. The mentioned groups are crucial for creating robust cement formulations to line the wellbore at intervals with abnormally high pressure effectively. Laboratory experiments were conducted utilizing various equipment such as the ZM-1003 consistometer, “Sroki” autoclave, “Vicat apparatus,” and AzNII cone. These experiments were based on standard methodologies for analyzing cement slurry and paste properties. During these tests, a particular reagent was introduced, demonstrating the ability to plasticize cement slurries, enhancing their fluidity and enabling precise control over the density of concentrated slurries. The laboratory findings regarding the control of concentrated slurry density were particularly noteworthy. These experiments involved analyzing compositions consisting of pure Portland cement and cement slurries augmented with the hyperplasticizer reagent. The results underscored this additive’s significance in enhancing cement slurry properties, offering improved fluidity and enabling effective density control. This contextualization highlights the pivotal role of the mentioned reagent in optimizing cement formulations for the challenging conditions encountered in well drilling and cementing operations. The added reagent was found to effectively plasticize the pastes, increasing their fluidity and reducing the water-cement ratio, which leads to the formation of paste with increased strength. The results of industrial testing of the reagent during cementing of production string in one of the wells confirmed the possibility of preparing concentrated slurry with a density of 2.4 g/cm³, thus ensuring successful cementing operations under high-pressure conditions. This study provides practical value for well drilling companies and cementing service providers, justifying the use of reagent-hyperplasticiser in concentrated slurries, which opens new perspectives for the creation of high-strength cement slurries when drilling wells, especially in conditions of abnormally high-pressure zones, thus improving cementing technologies and providing more reliable casing slurry strength.