Enhanced Natural Gas Liquid Recovery Process

1 . A method comprising:

receiving a hydrocarbon feed stream;

separating the hydrocarbon feed stream into a heavy hydrocarbon rich stream and a recycle stream, wherein the recycle stream comprises a gas selected from the group consisting of carbon dioxide, nitrogen, air, and water; and

separating the recycle stream into a natural gas liquids (NGL) rich stream and a purified recycle stream.

2 . The method of claim 1 , further comprising injecting the purified recycle stream into a subterranean formation.

3 . The method of claim 1 , further comprising:

separating the recycle stream into a vapor recycle stream and a liquid recycle stream; and

dehydrating the vapor recycle stream.

4 . The method of claim 3 , further comprising dehydrating the liquid recycle stream.

5 . The method of claim 1 , further comprising:

separating the recycle stream into a vapor recycle stream and a liquid recycle stream; and

dehydrating the liquid recycle stream.

6 . The method of claim 1 , further comprising separating the recycle stream into a vapor recycle stream and a liquid recycle stream, wherein the vapor recycle stream and the liquid recycle stream are fed to the separation of the recycle stream as separate streams.

7 . The method of claim 6 , wherein separating the vapor recycle stream and the liquid recycle stream comprises using a three-phase separator.

8 . The method of claim 1 , further comprising dehydrating at least a portion of the recycle stream prior to separating the recycle stream into the NGL rich stream and the purified recycle stream.

9 . The method of claim 1 , wherein separating the recycle stream comprises:

separating the recycle stream into the purified recycle stream and a sour NGL rich stream; and

sweetening the sour NGL rich stream, thereby producing the NGL rich stream.

10 . The method of claim 9 , further comprising:

cooling the sour NGL rich stream prior to sweetening the sour NGL rich stream; and

throttling the sour NGL rich stream prior to sweetening the sour NGL rich stream.

11 . The method of claim 9 , wherein the NGL rich stream comprises no more than about 5 percent acid gases.

12 . The method of claim 1 , further comprising:

separating the NGL rich stream into a heavy NGL stream and a light NGL stream; and

mixing the heavy NGL stream with the heavy hydrocarbon rich stream.

13 . The method of claim 12 , further comprising:

separating the recycle stream into a vapor recycle stream and a liquid recycle stream, wherein the vapor recycle stream and the liquid recycle stream are fed to the separation of the recycle stream as separate streams; and

dehydrating at least one of the vapor recycle stream and the liquid recycle stream.

14 . The method of claim 12 , wherein the heavy hydrocarbon rich stream has a Reid vapor pressure of less than 6 after being mixed with at least a portion of the heavy NGL stream.

15 . The method of claim 12 , wherein the light NGL stream has an energy content of between about 1,000 British thermal units per cubit foot (Btu/ft 3 ) and about 1,200 Btu/ft 3 .

16 . The method of claim 12 , wherein the light NGL stream has a vapor pressure of less than about 250 pounds per square inch gauge (psig) at a standard temperature.

17 . The method of claim 12 , further comprising:

combining a second NGL rich stream with the NGL rich stream prior to separating the NGL rich stream; and

separating the second NGL rich stream along with the NGL rich stream to form the heavy NGL stream and the light NGL stream.

18 . A plurality of process equipment configured to:

receive a hydrocarbon feed stream;

separate the hydrocarbon feed stream into a heavy hydrocarbon rich stream and a recycle stream comprising at least one C 3+ hydrocarbon and a gas selected from the group consisting of carbon dioxide, nitrogen, air, and water; and

separate the recycle stream into a natural gas liquid (NGL) rich stream and a purified recycle stream.

19 . The process equipment of claim 18 , further configured to:

separate the NGL rich stream into a heavy NGL stream and a light NGL stream; and

mix at least a portion of the heavy NGL stream with the heavy hydrocarbon rich stream.

20 . The process equipment of claim 18 , wherein the NGL rich stream comprises less than about 70 percent of the C 3+ hydrocarbons from the recycle stream.

21 . The process equipment of claim 18 , wherein the NGL rich stream comprises from about 10 percent to about 50 percent of the C 3+ hydrocarbons from the recycle stream.

22 . The process equipment of claim 18 , wherein the process equipment configured to separate the recycle stream into the NGL rich stream and the purified recycle stream is configured to:

separate the recycle stream into a vapor recycle stream and a liquid recycle stream; and

separate the vapor recycle stream and the liquid recycle stream into the NGL rich stream and the purified recycle stream.

23 . The process equipment of claim 22 , wherein the recycle stream is separated in a separator, and wherein the vapor recycle stream and the liquid recycle stream enter the separator as separate streams.

24 . The process equipment of claim 19 , wherein the heavy hydrocarbon rich stream has a Reid vapor pressure of less than 6 at a temperature of about 100° F. after being mixed with the heavy NGL stream.

25 . The process equipment of claim 19 , further configured to:

combine a second NGL rich stream with the NGL rich stream prior to separating the NGL rich stream; and

separate the second NGL rich stream along with the NGL rich stream to form the heavy NGL stream and the light NGL stream.