Carbon storage process 101: navigating the lifecycle

Introduction

Carbon Capture and Storage (CCS) is a high impact decarbonization lever being used by larger E&P companies and consortiums to offset their carbon emissions to meet decarbonization targets. Of the six decarbonization levers (Figure 1) being utilized, CCS is the most CAPEX intensive, but perhaps the most critical, with a projected requirement for 1050 dedicated CCS projects by 2050.

These projects utilize a highly collaborative and multi-discipline team working together for several years. However limited data can make these projects exceptionally challenging, taking up to 3 years to reach a financial investment decision (FID). This in part accounts for how few operational CCS projects there are globally. The role that CCS has in attaining decarbonization goals follow a comprehensive process which incorporates the combination of innovative technologies and technical expertise to help reduce the time taken to pass through the various decision gates and deliver safe long-term and cost-effective storage of CO₂.

Figure 1: The six decarbonization levers (modified from McKinsey Energy Insights - Global Energy Perspective 2022.

The carbon storage process

Throughout the CCS lifecycle, decision gates control the progression from project stage to the next (Figure 2) - from project initiation, through assessment and concept selection, detailed design, operations, and Post Injection Site Closure (PISC). Each project stage presents a different set of insights, challenges, and questions that need to be addressed.

Figure 2: CO₂ storage challenges and process.

Initiate
The first challenge is to locate regions and sites that have the potential to store CO₂. Extensive screening workflows need to be undertaken - a lengthy process which can be further complicated by lack of data.

The key questions to be addressed during this stage are:

• Where are the prospective storage resources?
• What stratigraphic intervals could provide effective reservoirs and seals?

A traditional approach to fairway screening can take many months to arrive at a first pass assessment of suitable sites that warrant closer investigation. This stage of work would therefore benefit greatly from being able to access global content and automated workflows running this first pass assessment of reservoir seal presence, effectiveness, and potential supercritical state of CO₂.

Assess
Once potential sites have been identified, the next phase of activity assess their feasibility and identify potential concepts. This requires the following questions to be addressed:

• What are the geological controls?
• What is the prospective resource capacity?
• What is the injectivity potential?
• Can CO₂ be safely contained?

These calculations benefit from robust subsurface characterization and the creation of comprehensive plume migration and containment models. With so many potential variables, multiple scenarios are often run and comparisons made before the progressing to the next stage. This can be both time and resource intensive.

Select
The assessment of potential sites generates a list of viable options which can then be further narrowed down to a single site and a single storage concept during the Select phase. The key question here is: can we inject CO₂ at a sufficient rate?

The Pre-FEED part of the process requires an appreciation for the baseline conditions for injection which are then used to run and test multiple scenarios. This analysis evaluates the impact of a variety of variables on the injectivity of CO₂ overtime. These include:

• Inflow rate variability.
• Casing and completion configuration.
• Reservoir parameters such as porosity and permeability.
• Injection scheduling options to explore the impact of CO₂ injection within the well-bore and its immediate vicinity.

This multi-scenario analysis is required to calculate a safe operation envelope and selection of the most appropriate storage injection concept.

Define
The next stage of activity is to create and develop a storage development and MMV plan during the FEED phase of activity. These plans span the lifetime of the project and incorporate regulatory requirements. To demonstrate that these requirements can be met, specific containment risks need to be identified and given detailed consideration so the appropriate mitigation plans can be devised documented.

If the storage development and MMV plans meet the necessary requirements, a single storage concept can pass through the FID gate and more detailed engineering activity can commence.

Execute
Before operations can commence, detailed engineering designs and multi-scenario analysis is used to identify the optimal well design for safe and cost-effective operations. This is done while taking into consideration Scope 1 and Scope 2 emissions to ensure operators stay withing the required limits.

Operate
The operational stage requires management and visualization of CO₂ stream supply, monitoring injection rates, and continual verification of plume development and migration. Real time monitoring data must be incorporated into a dynamic and evergreen plume model as part of a digital twin of the storage model. This will allow adjustments to be made to the development plan in line with new data and the insights to maintain safe and efficient operations.

PISC
The Post Injection Site Closure is the final stage of the carbon storage process and requires the successful implementation of the containment risk-driven, cost optimised long-term monitoring strategies developed in previous phases of activity. During this stage the questions being posed are:

• Is the plume behaving has predicted?
• Has the plume migration stabilized?
• What will the costs of plug-in and abandonment be?

During this stage, the behaviour of the CO₂ is monitored and modeled post-injection by observing pressure changes within the reservoir to validate predictions and ensure plume migration has stabilized. It can also include groundwater monitoring as means of detecting migration of CO₂ or brines out of the injected zones.

A reporting program with a defined schedule is implemented that aligns to specific regulatory requirements of the project. This helps ensure that appropriate stakeholders are aware of the project status, site closure plans and estimated costs.

Summary

The full lifecycle of CO₂ project can span decades and represent a long-term investment both in terms of resources and finance. While there is a growing number of potential projects in the pipeline, relatively few are yet to pass through FID. This in part is due to the labour intensive and lengthy nature of traditional workflows. If decarbonization goals are to be met the time it takes to reach FID needs to be greatly reduced. This is going to require embracing automated workflows designed specifically for undertaking the CO₂ Storage Process and leveraging the right technical expertise throughout the carbon storage lifecycle.

In an upcoming series of spotlight articles, Halliburton Landmark experts will explore in more detail how DecisionSpace^®365 CO₂ Storage Suite can help accelerate the different stages of activity.