Natural gas liquid recovery process

A method comprising:

• receiving a hydrocarbon feed stream comprising at least one C3+ hydrocarbon, at least one C9+ hydrocarbon, acid gas, and a gas selected from the group consisting of carbon dioxide, nitrogen, air, and water;
• separating the hydrocarbon feed stream into a heavy hydrocarbon rich stream and a recycle stream, wherein the heavy hydrocarbon rich stream comprises most of the C9+ hydrocarbon in the hydrocarbon feed stream, wherein the recycle stream comprises most of the C3+ hydrocarbon and most of the acid gas in the hydrocarbon feed stream, and wherein the acid gas is selected from the group consisting of carbon dioxide, nitrogen, air, and water;
• separating the recycle stream into a sour natural gas liquid (NGL) rich stream and a purified recycle stream, wherein the sour NGL rich stream comprises some of the C3+ hydrocarbon and some of the acid gas in the recycle stream, and wherein the purified recycle stream comprises most of the C3+ hydrocarbon and most of the acid gas in the recycle stream;
• and
• separating the sour NGL rich stream into a sweet NGL rich stream and an acid gas stream, wherein the sweet NGL rich stream comprises substantially all of the C3+ hydrocarbon in the sour NGL rich stream, and wherein the acid gas stream comprises substantially all of the acid gas in the sour NGL rich stream,
• wherein the hydrocarbon feed stream, the recycle stream, and the sour NGL rich stream are not subjected to cryogenic conditions, membranes, and carbon dioxide recovery solvents between being received and being separated into the heavy hydrocarbon rich stream, the sweet NGL rich stream, the purified recycle stream, and the acid gas stream, and
• wherein carbon dioxide, nitrogen, and air are not removed from the hydrocarbon feed stream and are not removed from the recycle stream prior to separating the recycle stream into the sour NGL rich stream and the purified recycle stream.

A method comprising:

• receiving a hydrocarbon feed stream, wherein the hydrocarbon feed stream comprises carbon dioxide, natural gas liquid (NGL), and heavy hydrocarbons, wherein the NGL comprises C3-C8 hydrocarbons, and wherein the heavy hydrocarbons comprise C9+ hydrocarbons;
• separating the hydrocarbon feed stream into a heavy hydrocarbon rich stream and a carbon dioxide recycle stream, wherein the heavy hydrocarbon rich stream comprises most of the C9+ hydrocarbons in the hydrocarbon feed stream, and wherein the carbon dioxide recycle stream comprises most of the carbon dioxide and most of the C3-C8 hydrocarbons in the hydrocarbon feed stream;
• separating the carbon dioxide recycle stream into a sour NGL rich stream and a purified carbon dioxide recycle stream, wherein the sour NGL rich stream comprises some of the C3-C8 hydrocarbons in the carbon dioxide recycle stream, and wherein the purified carbon dioxide recycle stream comprises most of the carbon dioxide in the carbon dioxide recycle stream;
• separating the sour NGL rich stream into a sweet NGL rich stream and a carbon dioxide rich stream, wherein the sweet NGL rich stream comprises the substantially all of the C3-C8 hydrocarbons in the source NGL rich stream, and wherein the carbon dioxide rich stream comprises substantially all of the carbon dioxide in the sour NGL rich stream;
• combining a carbon dioxide makeup stream from a source external to the method with the purified carbon dioxide recycle stream;
• and
• subsequently injecting the combined carbon dioxide makeup stream and the purified carbon dioxide recycle stream into a subterranean formation,
• wherein the carbon dioxide is not removed from the hydrocarbon feed stream and is not removed from the carbon dioxide recycle stream prior to separating the carbon dioxide recycle stream into the sour NGL rich stream and the purified carbon dioxide recycle stream, and
• wherein the hydrocarbon feed stream, the carbon dioxide recycle stream, and the sour NGL rich stream are not subjected to cryogenic conditions, membranes, and carbon dioxide recovery solvents between being received and being separated into the heavy hydrocarbon rich stream, the purified carbon dioxide recycle stream, the sweet NGL rich stream, and the carbon dioxide rich stream.