Asset Retirement Obligation Series
Plan Twice. Execute Once.
In our last post, we discussed pipeline due diligence and the costs that could be avoided by simply verifying responsibility before beginning a decommissioning project.
With this post we will stay on track with our planning and preparation theme, focusing on preparing for platform removal. Bringing a derrick barge to the job site is a significant investment. To make sure you are spending wisely, completing the proper analysis and planning before barge arrival needs to be a priority.
Don’t Skip Risk-Reward Analysis!
Risk-reward assessment is the vital first step in platform preparation. Determining whether to take a piece-small approach, or remove the platform as a whole is a key decision. Dividing the platform for piece-small removal allows for a less costly barge to remove it, but safety implications and project time must be reviewed. Consequently, the increased cost of utilizing a large barge to remove the platform in one lift must be considered.
Striking the right balance depends on the parameters of the project, and the priorities and constraints of the operator in charge of the asset. Time and safety are the biggest factors to consider. A larger derrick barge can be quicker, but much more expensive. Every situation is different, so remember, plan twice and execute once.
With a Plan in Place, Prepare the Platform
Once you’ve decided on the best removal method for your project, the first step in platform preparation is to prepare for hot work, such as cutting and welding. This entails draining all liquid in piping and tanks into the platform sump and flushing all areas that originally contained hydrocarbons or other dangerous or contaminated liquids. All these liquids are then loaded in approved tanks for transport to land and proper disposal.
After liquids are drained and hot work is complete, the topside structure must be prepared for lift. This is where the results of your risk-reward assessment will have the biggest effect. Depending on your decision, these final steps can include replacing or adding pad eyes, or adding bracing to reinforce the structure. Equipment to be removed by the barge must be cut loose if it is to be lifted separately. At this point, the deck could also be pre-cut into sections for piece-small removal. The final cuts will be made when the deck is ready to be lifted.
TSB Offshore Is Here To Help
Platform preparation varies by platform type and size. Balancing the risk, cost, and safety implications is critical to making the best decision for your project. That is where TSB can offer support. With 25 years of data on all aspects of decommissioning, we’re here to ensure all of the options have been examined and the end decision is the best one for you.
We have a chart available illustrating the estimated time to allocate for various types of structure removals. If you would like to receive a copy, please hit reply, write chart in the email body, and we’ll send it right over.