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Qualification Services for Brownfield Carbon Storage


Abandoned Oil and Gas wells with insufficient barrier integrity pose the greatest threat of loss of containment in brownfield Carbon Storage. When a Carbon Storage project founders in the planning stage, it typically founders on the inadequate mitigation of this risk.


Qualifying historic abandonments, both in individual wells and across one or more fields which may comprise a CO2 containment area, remains a critical challenge for the Carbon Storage industry. The scale and complexity of assessing cementation, plug design, number of plug locations and crossflow solutions which have altered the overburden 'plumbing' can be overwhelming in even a small group of wells without the right tools and workflows to tackle the problem.

Stag has developed the right tools, and we have the solution. 

We deliver quantitative leakage prediction at all scales.


Qualify historic abandonments.

Whether there are one or one hundred well penetrations in your brownfield Carbon Storage project, our tools for assured P&A planning can be seamlessly used to describe, risk and qualify historic well abandonments of any age or design, and even where very little well information exists.


Our Geological Engineering Model (GEM) can be used to evaluate, assess and risk historic well abandonments in comprehensive detail. By preparing a GEM for an historic well, you will be able to qualify the rock strength around every single barrier for CO2 Containment.


By using the GEM to understand the way in which permeable rocks in the overburden may have been allowed to communicate following hydrocarbon P&A, you will be able to quantify the risk of leakage arising from loss of lateral containment and derisk any unforseen pathways to surface.


By using our Annular Integrity Evaluation and Bond Log Verification services to understand the potential for geological and cement bond behind casing, you can make a model of the integrity of any barrier of any construction and every age.

Image by Zachary Theodore

Qualify the rock strength of every existing barrier in your Carbon Storage project.

By preparing a GEM for every historic well, you will be able to achieve assurance that historic barriers are placed against impermeable rocks with sufficient strength to retain not only brownfield hydrocarbons but also a column of CO2 in any phase. For complete assurance, you can qualify barriers against CO2 columns originating from shallower depths than your primary injection target to assure each and every historic well against surface leakage even in the event of loss of reservoir containment. 

Image by Martin Adams

Qualify Barrier Numbers and Placement for Lateral Containment in every well.

By preparing a GEM for each historic well, you will be able to understand whether permeable rocks were allowed to communicate beneath barriers in the original P&A design, and what impact this might have on the migration both of the storage plume and any potential leaks. By preparing a GEM for every well, you will understand the potential for unplanned migration of CO2 as a consequence of hydrocarbon P&A.

Image by Ken Mathiasen

Assure Annular Containment with an understanding of barrier integrity in every well.

Our Annular Integrity Evaluation and Bond Log Verification services can be used to assess the cement and bond quality around any in-casing barrier whatever its age or construction. By assessing not only cementing information but geological contributions to bond such as shale or salt squeeze, our services will allow you to qualify the construction of every single barrier in your Carbon Storage project.

Pine Trees

Get the big picture to mitigate risk.

No matter how many wells you have in your Carbon Storage project, our detailed, risk-based and objective assessments of their geological and barrier construction integrity can be aggregated to describe leakage risk and its spatial distribution. 

When Carbon Storage projects contain multiple former hydrocarbon fields, differences in well construction, reservoir horizons and geometry, rock strength and the P&A philosophy of former operators will give rise to meaningful differences in risked Loss of Containment and Leakage Tolerance. By efficiently and rigorously interrogating well data with the GEM, these risks can be recognized, mitigated and managed from the planning stage.

Use Stag's specialist tools to break through the Well Integrity roadblock in your Carbon Storage project.

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