Enzymatic CaCO3 for Proppant Consolidation

Abstract

The application of enzymatic generation and precipitation of calcium carbonate for the use as in-situproppant consolidation is an environmentally green technology that shows promise in the Danish North Sea. Hydraulic fracturing of producers with the aid of proppants to keep fractures open can present a problem if the proppants are back-produced as this can cause erosion of the well and production facilities. These problems may result in delayed production and costly workovers. Enzymatic calcium carbonate, a technology to consolidate the proppants, can be applied right after a hydraulic fracturing treatment or at a later stage, when proppant reconsolidation is needed. In this paper, we report the findings of extensive lab experiments, under reservoir conditions, on consolidation of of three different proppant types. The results show that some proppants are easier to consolidate than others.