Subsea facility and method for processing gas from a subsea gas production field

A method for subsea processing of gas from a subsea gas production field, comprising successively:

• a step of cooling a gas/liquid mixture coming directly from at least one subsea gas production field so as to condense heavy hydrocarbons and water present in the gas/liquid mixture and to bring the gas/liquid mixture to a temperature lower than that of the gas in a gas export pipeline;
• and
• a subsea gas/liquid separation step for delivering processed gas to a gas export pipeline and liquid to a liquid export pipeline;
• wherein the gas/liquid separation step comprises a first gas/liquid separation step followed directly by a second gas/liquid separation step by coalescence in order to lower a dew point of the processed gas to a level allowing its export in monophasic form.

A subsea facility for processing gas from a subsea gas production field, comprising:

• a cooling module supplied with a gas/liquid mixture coming directly from at least one subsea gas field in order to cool the gas to a temperature allowing heavy hydrocarbons and water present in the mixture to be condensed;
• and
• a gas/liquid separation module supplied with a gas/liquid mixture coming from the cooling module and which delivers processed gas to a gas export pipeline and liquid to a liquid export pipeline;
• wherein the gas/liquid separation module comprises a gas/liquid separator and a coalescing filter separator which are connected in series, the gas/liquid separator having a gas outlet which is connected to an inlet of the coalescing filter separator and a liquid outlet which is connected to the liquid export pipeline, the coalescing filter separator having a gas outlet which is connected to the gas export pipeline and a liquid outlet which is connected to the liquid export pipeline;
• wherein the liquid export pipeline is provided with liquid pumping means.