A threaded pipe connection

A threaded pipe connection comprising:

• a tubular coupling with first and second female threaded zones formed in opposing sections;
• and
• first and second pipes, each comprising a male threaded zone and a shoulder surface at its terminal end,
• wherein each female threaded zone:
• extends from an inner end to an outer end, wherein the inner end of each threaded zone is the end nearest a centre of the tubular coupling;
• and
• includes a female thread that tapers radially within the female threaded zone from a maximum diameter at the outer end of the female threaded zone,
• wherein each male threaded zone includes a male thread that tapers radially so as to reduce in diameter towards the terminal end of the pipe,
• wherein the threaded pipe connection is configured to enable the first and second pipes to be engaged with the tubular coupling in a made-up configuration in which:
• the shoulder surfaces of the first and second pipes abut;
• the entire male threaded zone of the first pipe engages the entire first female threaded zone;
• the entire male threaded zone of the second pipe engages the entire second female threaded zone;
• and
• for each of the first and second female threaded zones:
• a crest of one of the male and female threads radially interferes with a root of the other of the male and female threads in a first portion of the female threaded zone and does not interfere or interferes by a smaller amount in a second portion of the female threaded zone;
• and
• the second portion is located at the inner end of the female threaded zone.