Use of History Matching and Pressure Analysis for Improving Conformance Assurance Using the in Salah Co2 Storage Case Study

Abstract

Time-lapse seismic imaging of the CO2 plume in the high-porosity Utsira Formation at Sleipner has proven very valuable in building confidence that the injected CO2 is safely contained within the storage unit in this world-first industrial scale offshore storage project. The In Salah CO2 storage project, with the more challenging low-porosity reservoir properties on the other hand, has provided the CCS community with a contrasting case to consider how conformance assurance can be achieved through a robust multi-disciplinary understanding of the injection/storage processes. This paper highlights the role of history matching and pressure analysis for improving conformance assurance, using the In Salah CO2 storage project case study. We show how the injection well performance can be characterised by periods of matrix and fracture flow, and how the characteristics of tensile and shear fracture modes can be identified using a holistic analysis of reservoir history-matching parameters and monitoring datasets.