Subsea fluid processing system

8:

• A subsea fluid processing system configured to receive a wellstream flow, the subsea fluid processing system comprising:
• a pressure control device configured to regulate a pressure of the wellstream flow;
• a gas-liquid separator unit configured to receive the wellstream flow downstream of the pressure control device and to provide a liquid stream and a gas stream;
• a first membrane separator configured to receive the gas stream and to provide a retentate stream and a permeate stream;
• a compressor configured to receive the permeate stream and to provide a compressed permeate stream;
• and
• a discharge cooler configured to receive the compressed permeate stream and to provide a cooled compressed permeate stream for injection into a subsurface reservoir,
• wherein, a density of the cooled compressed permeate stream is higher than a density of the compressed permeate stream.

9:

• The subsea fluid processing system as recited in claim 8, further comprising:
• a membrane unit;
• and
• a demister,
• wherein,
• the membrane unit comprises the first membrane separator and a second membrane separator which is arranged in series with the first membrane separator, and
• the demister is arranged between the first membrane separator and the second membrane separator.

10:

• The subsea fluid processing system as recited in claim 9, further comprising:
• a pressure vessel configured for subsea use and to have arranged therein a membrane cartridge assembly comprising a plurality of membrane cartridges,
• wherein,
• at least one of the first membrane separator and the second membrane separator is arranged in the pressure vessel, and
• the first membrane separator or the second membrane separator comprises the plurality of membrane cartridges.

12:

• The subsea fluid processing system as recited in claim 8, further comprising:
• an inlet cooler;
• and
• an inlet separator,
• wherein the inlet cooler and the inlet separator are each arranged in the wellstream flow upstream of the pressure control device.

20:

• A method of processing a wellstream flow, the method comprising:
• operating a pressure control device to regulate a pressure of the wellstream flow;
• receiving the wellstream flow in a gas-liquid separator unit;
• operating the gas-liquid separator unit to provide a liquid stream and a gas stream;
• receiving the gas stream in a first membrane separator;
• operating the first membrane separator to provide a retentate stream and a permeate stream;
• compressing the retentate stream in a compressor to provide a compressed permeate stream;
• cooling the compressed permeate stream in a discharge cooler to provide a cooled compressed permeate stream;
• and
• injecting the cooled compressed permeate stream into a subsurface reservoir,
• wherein,
• the method is performed in a subsea environment.