摘要 |
<p>The concentric tubing completion system of the present invention comprises a surface christmas tree which is located on a surface structure, a tieback connector which is secured to a mudline wellhead that is installed at the upper end of a subsea well bore, a mudline tubing hanger which is supported in the tieback connector, and a pair of concentric tubing strings which are suspended from corresponding tubing hangers in the surface christmas tree and connected to the mudline tubing hanger. The annulus between the concentric tubing strings communicates with a number of passages in the mudline tubing hanger which are connected to the tubing annulus below the mudline tubing hanger. Thus, lift gas or other fluids may be communicated between the surface christmas tree and the tubing annulus between the concentric tubing strings.</p> |