Sand Failure: Effect of Biocide on the Geomechanical Properties of Outcrop Carbonate Rock Under Static Conditions

Abstract

The effects of chemical interaction of a biocide with formation rocks on the rock geomechanical strength were examined. A combination of analytical tests (Scanning Electron Microscopy/Energy-Dispersive X-Ray Analysis—SEM/EDX, X-Ray Powder Diffraction—XRPD and Particle Size Distribution) and uniaxial compressive test was used in this study. The particle size distribution showed an increase in D₅₀ with poor sorting for the chemically treated carbonate core sample. The XRPD shows evidence of altered minerals in the chemically treated samples. It was observed that the interaction led to precipitation of new materials that clogged the pore space of the rock samples leading to about 150% increase in compressive strength of the carbonate following treatment with the biocide. The results give more insight into the limitations of the existing sand production prediction models with respect to the effect of oilfield chemicals on the strength of the reservoir rocks.