Cement to formation bond strength evaluation using image analysis

Abstract

For inventing improved cements for effective zonal isolation, it is important to evaluate the bond strength of the cement. We have designed an experiment to assess the cement bond strength based on the flow of cement through the formation. The experiment involves quantitative analysis on a sequence of slices from X-ray Computed Tomography scans to study the change in porosity from the cement end to the formation end in a composite specimen. The number of slices where the change in porosity occur is used to estimate the bond strength of the cement. Our observations show that cement-to-formation bond strength depends on the permeability of the formation at the interface if we keep other physical (rock sample preparation methods, cement curing and measurement conditions), and chemical (cement additives) factors constant.