Storage caverns have been widely used by different petrol companies as a means of storing hydrocarbons like LPG, propane, butane, ethylene, ethane, gasoline, natural gas, crude oil, and fuel oil deep inside the earth through a combination of techniques like drilling and solution mining.
Most storage caverns are built on salt deposits, thus making them more known as salt caverns. What makes storage caverns highly preferred as a means of storing is because salt caverns are very safe storage compartments and are very secure. Aside from this, creation and maintenance of such storage caverns is also very economical as the process costs far less than if you were to build silos as hydrocarbon compartment bins.
Creating salt caverns as storage caverns is very difficult and requires the expertise of those who have had a hand in creating perfectly good and highly usable ones themselves. Of course, this doesn’t just end there as there are a lot of testing that needs to be done in order to ensure the reliability of the storage cavern. Mechanical integrity test is one of the tests used in identifying if the cavern that have been built is suited enough to carry the amount, weight, and volume of the hydrocarbon that will be stored within the cavern itself.
Storage caverns are very cost effective for oil companies because there is hardly any maintenance required in ensuring that the oil reserved placed there leaks, evaporates, or destroys surrounding vicinities. This is because storage caverns created in salt deposits are very secure.
During the drilling part of the project in order to reach salt deposits, a workover is done on the wellbore once it has been initially completed. In fact, this is not only the case where storage cavern work overs will be done as there are times this may be required to ensure that the storage cavern effectively fulfill its purpose. All-in-all, workovers are done due to:
- Unsatisfactory production or injection rates
- Regulatory requirements
- Competitive drainage
- Supplemental recovery
- Reservoir data gathering
- Lease requirements
A workover is done as a means to intervene invasively with the well of the storage cavern. Workover is a very expensive process but it beats having to replace everything. A workover is quite complex and requires highly skilled crews to execute this challenge. Most of the time, this task is performed if a well is deemed unsuitable for the current job it will be doing.