Slim-bore tubing hanger

A subsea wellhead assembly, comprising:

• a wellhead housing for placement at an upper end of a well;
• a tubing spool connected to an upper end of the wellhead housing, the tubing spool having a landing shoulder,
• a plurality of auxiliary passages extending through and spaced circumferentially around the tubing spool;
• a receptacle on an exterior of the tubing spool in communication with the auxiliary passages;
• a tubing hanger landed on the shoulder in the tubing spool for supporting a string of tubing;
• a plurality of auxiliary ports spaced circumferentially around the tubing hanger that mate with the auxiliary passages for communicating with auxiliary lines extending downward alongside the tubing from the tubing hanger;
• a production tree assembly mounted to an upper end of the tubing spool for receiving well fluids flowing upward through the tubing hanger;
• a control unit mounted to the production tree assembly for controlling electrical and hydraulic functions of the tree assembly;
• and
• a flexible lead extending from the control unit for communicating the control unit with the auxiliary lines and having a plug that connects to the receptacle.

A method of completing and producing a subsea well, comprising:

• providing a tubular housing assembly at an upper end of the well with a plurality of auxiliary passages extending through and spaced circumferentially around the housing assembly;
• securing a tubing hanger to a string of tubing, the tubing hanger having a plurality of auxiliary ports spaced circumferentially around the tubing hanger that are in communication with auxiliary lines extending alongside the string of tubing;
• landing the tubing hanger in the housing assembly and mating the auxiliary ports with the auxiliary passages, thereby communicating the auxiliary passages with the auxiliary lines;
• and
• landing a production tree assembly on an upper end of the housing assembly and receiving well fluids flowing upward from the tubing hanger.