The purpose for energy companies is to optimize well costs and identify ways to meet production targets with less expenditure. In this blog post, we share four ways in which the Relief Well Injection Spool (RWIS), a specialist piece of subsea hardware, can unlock significant cost saving opportunities during field development.

Although the RWIS has primarily been designed to enable single relief well contingency, the advantages it can bring operators goes well beyond this – enabling operators to maximize production while simultaneously reducing CAPEX costs.

1. Increase size of wellbore, to maximize flow rates

By having access to the RWIS, you can increase the size of your completion bores. This would allow you to significantly maximize flow rates and the profitability of your wells, without the need for multiple relief wells and the associated hardware – as the RWIS will enable you to inject the necessary kill mud through a single relief well to kill the well.

Essentially, you are able to do more with less – increasing the rate of flow without the requirement for additional relief wells. The RWIS gives you the means to kill your big bore well, so you can reap the economic benefits during normal operations.

Having big bore completions also has significantly beneficial knock-on effects, which leads on to our next two points…

2. Meet production costs with fewer wells

As big bore completions increase flow rates, you will be able to meet production targets with less wells. And the cost savings associated with this can be staggering.

For example, to hit your production targets you may need 14 conventional wells, but with big bore completions, the number of wells required reduces to 8. If each of your wells costs $50million to drill, that is an instant cost saving of $300million.

3. Reduce equipment and materials costs

Both of the above points have knock-on effects with regards to equipment and materials required, which can unlock further cost savings.

With big bore completions, your casing and liner requirements can be reduced because:

• Less casing diameter sizes may be needed, and you could eliminate the last string from the casing design
• You may not need a liner to isolate different pay zones to minimize flow rates, as the RWIS may allow you to provide the elevated injection rates needed during a dynamic kill event to kill a high rate well.

By reducing the number of wells, you can realize further equipment and material cost savings, from the seabed all the way to the surface. Some examples include:

• Less subsea architecture is required, including trees, manifolds and risers
• Less risers mean smaller topside facilities. Your topside platform can be smaller as it doesn’t need to support as many risers.

Post-incident cost savings:

4. Shallower relief well intercept

While not necessarily a consideration at the field development stage, this is an often overlooked economic benefit of the RWIS if an incident were to occur. In the event of a well control incident on a well that can be killed with a single relief well at the shoe, having access to the RWIS and the additional pumping capacity it provides allows you to have the ability to perform a shallower intercept of the target well where elevated injection rates are required. This allows for a quicker intercept and well kill operation.

The knock-on costs savings from being able to drill the relief well quicker can be vast. Being able to perform a shallower intercept directly reduces the time to kill the well which in turn reduces the environmental impact and human risk, reduces the barrels of oil lost, reduces potential fines and so much more.