System and method for reducing nitrogen content of GSP/expander product streams for pipeline transport

A method for removing nitrogen and for producing a methane product stream, the method comprising:

• providing a feed stream comprising nitrogen and methane;
• separating the feed stream into a first overhead stream and a first bottoms stream in a first separator;
• separating the first overhead stream into a second overhead stream and a second bottoms stream in a second separator;
• splitting the second overhead stream into a first portion and a second portion;
• separating the first portion of the second overhead stream into a third overhead stream and a third bottoms stream in a first fractionating column;
• separating the first bottoms stream, the second bottoms stream, the second portion of the second overhead stream, and the third bottoms stream into a fourth overhead stream and a fourth bottoms stream in a second fractionating column;
• expanding the second portion of the second overhead stream prior to entering the second fractionating column;
• cooling at least a portion of the feed stream upstream of the first separator through heat exchange with the fourth overhead stream;
• cooling the first overhead stream upstream of the second separator through heat exchange with the fourth overhead stream;
• cooling the first portion of the second overhead stream upstream of the first fractioning column through a subcooler heat exchange with the fourth overhead stream;
• further cooling the first portion of the second overhead stream downstream of the subcooler and upstream of the first fractionating column through heat exchange with the third bottoms stream and the third overhead stream;
• compressing the fourth overhead stream to produce a methane product stream;
• and
• pumping at least a portion of the fourth bottoms stream to produce a natural gas liquids product stream.