Completion tools, catalog page 63
Milling Extension Sub & X-Over
Fishing neck below the packer and connection crossover
Milling extension sub
Both ends of the milling extension sub have gas-tight connections. It is connected below the packer; when milling and fishing are needed, a special fishing tool is run to the milling extension sub to fish the string below the packer.
X-over
The X-over converts between connection types and is usually connected below the milling extension sub and packer.
