DHSV scale removal method in the production string

A downhole safety valve (DHSV) scale removal method in a production string, the method comprising:

• opening a first wet Christmas tree (WCT) valve that gives access from a production line to an interior of the production string;
• pumping a 1st diesel spacer cushion;
• pumping an alkalizer cushion in a volume 1.5 times a volume of acid to be pumped;
• pumping a 2nd diesel spacer cushion with a volume equal to that of the 1st diesel spacer cushion;
• pumping a diesel, butyl glycol, and xylene (DBX) cushion;
• pumping completion fluid to displace a front of the 1st diesel spacer cushion to the first WCT valve, then stopping pumping;
• closing the first WCT valve that gives access to the production string;
• opening a second WCT valve that gives access to a lift gas line;
• pumping the 1st diesel spacer cushion, the alkalizer cushion, and the 2nd diesel spacer cushion to an interior of the lift gas line;
• closing the second WCT valve that gives access to the lift gas line;
• opening the first WCT valve that gives access to the production string;
• pumping a cushion of DBX and the acid to the interior of the production string up to the DHSV;
• waiting for a contact time between 30 minutes and 1 hour for CaCO3 removal reaction;
• opening the second WCT valve that gives access to the lift gas line;
• and
• opening a well for cleaning and simultaneously pumping, through the lift gas line, a neutralizing solution to neutralize the acid produced by the well, mixed with oil.