This project addresses the controls on mechanical failure within mudrock seals – a key element in de-risking CO₂ storage (CS) targets. It forms part of the first phase of the Mudrock Seals in CO₂ Storage Systems research theme the focus of which is the >180 m thick Early Jurassic Redcar Mudstone Formation that crops out along the NE Yorkshire coast and is a direct analogue for offshore CS targets in the North Sea. The Redcar Mudstone Formation is divided into several members with differing compositions that are faulted and pervasively fractured (Fig. 1). It is, therefore, an ideal case study for investigating the impact of composition, sedimentary facies and faulting on the mechanical failure of mudrock seals.

Research programme

Sampling and structural analysis of the Redcar Mudstone Formation will be undertaken along the NE Yorkshire coast. Detailed sedimentary logging of the mudstone succession will take place concurrently as part of Project 1 (CASP.MSP.1). The aim is to characterise the fracture network throughout the mudstone succession and assess how faulting and compositional heterogeneities have impacted the mechanical failure of the seal. Macrostructural field observations will be complemented by microstructural thin section and SEM observations. Compositional, TOC, poro-perm and MICP data will be collected for samples from fault damage zones.

Deliverables

Results will be delivered via an interim data release and associated presentation for clients, as well as a final technical report containing:

Controls on the mechanical stratigraphy of the mudrock seal

The macrostructural style and density of the fracture network within the various mudstone facies and members of the Redcar Mudstone Formation will be presented on stereoplots and interpreted outcrop images. Petrographic and SEM microstructural analysis will also be conducted representative samples. The structural results will be interpreted in the context of compositional data derived from SEM, petrography, TOC, poro-perm and MICP analyses obtained as part of Project 1 (CASP.MSP.1).

Impact of fault damage zones on the mechanical failure of the mudrock seal

Structural and compositional (SEM, petrography, TOC, poro-perm, MICP) data collected from samples across fault damage zones will be used to assess the impact of faulting on the mechanical failure of the Redcar Mudstone Formation.

The project will conclude with a client workshop during which all data and interpretations will be presented and discussed.

Project duration

The project was launched at the beginning of July 2022 and has a planned duration of 30 months.

Contact(s): Adam Szulc for further information on this research and licensing options.