System and method of pressure reduction and drainage of annulus of flexible pipes

The invention presents a system and method for reducing pressure and draining the annulus of submerged flexible pipes, with application in all flexible pipe structures and in any industry that uses these types of pipes. Its objectives are to eliminate condensed water and reduce the partial pressure of CO2, thus restoring the integrity of the pipes. In addition, with the reduction of the pressure of the annulus gases, the operations of collection of the pipes can be carried out with greater speed, that is, in less time. The previous relief of the annulus pressure further reduces the risk of rupture of the outer cap during the operation, thus reducing the risk of exposing operators to the presence of harmful gases, when the pipe reaches the deck of the PLSV vessel.