Method of evaluating cement-to-formation bond strength with computed tomography image analysis

Abstract

Invention of new cements for effective zonal isolation requires bond strength evaluation of the cement to formation. We present a method to evaluate the cement-to-formation bond strength based on the flow of cement through a formation using image analysis. Most researchers perform image analysis on a single slice. This is the first known nondestructive method devised using a quantitative analysis on a sequence of slices from X-ray computed tomography (CT) scans. The number of CT scan slices in which the porosity changes is used to evaluate the bond strength of cement. Our findings demonstrate that the cement-to-formation bond strength is affected by permeability of a formation and viscosity of cement if other physical (sample preparation and measuring conditions) and chemical (cement additives) variables remain constant.