The problem of comprehensive utilization of associated gas for the benefit of the oil company has remained an elusive dream and the task was to solve the problem with simple economical complexes with the allocation of components that meet the requirements of motor fuel standards for the needs of energy, domestic consumption and heating of oil in winter.

To solve the problem, a new recycling technology is proposed without incineration and emissions into the atmosphere using modular installations for use in fields where hydrogen sulfide and mercaptans are absent in the gas. Associated gases with a high content of acidic components are disposed of using another independent technology.

Currently available special gas utilization systems are 3 times more expensive than the cost of modular installations (excluding the operating costs of replacing expensive sorbents) and do not guarantee continuity of operation.

The main feature of the proposed technology is the comprehensive utilization of associated petroleum gas by liquefying the entire volume of incoming gas, while simultaneously dividing into commodity components in special ready-to-operate modules without rotating mechanisms.

Modular installations make it possible to obtain the following products: liquefied natural gas, propane - butane and condensate with thawing products that can be used as heating fuel, as well as solvents of varnishes and paints.

To ensure the process of continuous utilization of petroleum gas, two modules of four blocks each will be required, since the presence of moisture in the petroleum gas forms gas hydrates, which reduce the throughput and requires switching off the module for 2 hours (in winter) to warm the surface.

The connection of the second module guarantees the continuity of the recycling process and an increase in productivity during seasonal gas shortages.

The utilization complex includes the following main equipment: a compressor for compressing raw gas, two modular four-unit liquefaction and separation units, high and low pressure cryopumps for distributing liquefied natural gas, cryostats for collecting and storing gas, storage tanks for propane-butane fraction, as well as condensate.

• the raw gas enters one of the compressors and, after its compression to 4.0 MPa, is sent to the first unit of the module, where its temperature decreases due to heat exchange with the reverse cold flow.
• The low-pressure dry gas flow coming out of the first block is directed to the production of electricity or to other needs of the field;
• in the second block, due to cooling by oncoming liquid and gaseous cold streams, the temperature decreases further and heavy hydrocarbons from C5 to hexane are released from the gas, which are discharged into the collector tank;
• in the third block of the module, additional cooling of the input stream occurs and this ensures condensation and release of propane and butanes, which flow through the first two blocks counter to the input stream and are diverted to their collector;
• in the fourth block, the entire remaining input stream after additional cooling expands on the cold generators, lowering the pressure, which ensures the condensation of ethane and methane, which are discharged into their cryostat. The non-liquefied part of the very low temperature gas from the fourth block enters the upper part of the first block, which guarantees effective cooling of the input flow.The modular complex is easy to maintain, reliable in operation (20 years warranty), does not require electricity supply, does not need special sorbents, and also does not require additional costs for new jobs.