Utilization of vermiculite particles in the enhancement of the ilmenite based oil well cement properties

Abstract

Cementing the wellbore is one of the key jobs required for production from the reservoir. It is an essential part of the wellbore that supports the casing string and provides isolation between production and non-production zones. The challenging in situ conditions of reservoir can cause damage to the cement slurry. Hence, it is important to study various properties of this slurry under such conditions. The cement slurry should provide good strength, lower density variation, lower porosity and permeability and better rheological properties. The present study investigates the effect of vermiculite particles on ilmenite based Saudi class G cement. The cement powder, vermiculite and ilmenite were characterized using XRF analysis, particle size distribution and FESEM analysis. The performance of vermiculite as an additive was tested for different concentrations (0.25%, 0.50%, 1.0%, 2.0%, and 4.0% BWOC) and compared with base cement having no vermiculite content. The test includes rheological properties, compressive and tensile strength, elastic properties like Young's modulus and poison's ratio, density variation, and petrophysical properties like porosity and permeability calculation. It was observed from the results that at 2% BWOC addition of vermiculite, the performance of slurry was optimized for all the tests. At 2% BWOC addition of vermiculite, the yield point and gel strength were increased to maximum value while the porosity and permeability were found to be least. The compressive strength was increased by almost 10% and Young's modulus was reduced by nearly 44%. This study investigated for the first time the possibility of vermiculite to improve the ilmenite-weighted oil well cement and its experimental results emphasized the capability of vermiculite particles to enhance the properties of the ilmenite-based cement slurry and can be used as an additive.