Technological Schemes of Complex Oil, Gas and Condensate Processing Plants

The product obtained from wells on gas and gas condensate fields is always a complex heterogeneous mixture that contains a mixture of gases (saturated with water vapor and heavy hydrocarbons), liquid hydrocarbons (oil or gas condensate) and water, solid particles of rock, and other components. In order for the gas delivered to the consumer to meet all requirements placed upon it, it is necessary to eliminate the solid and liquid phases and also a part of the water vapor and heavy hydrocarbons before feeding it in the gas-transmission pipeline. These processes are carried out in special field devices of the complex preparation of a gas and condensate (DCPG). The typical design of the DCPG apparatus at a gas-condensate field is shown schematically in Fig. 1.1. The preparation of the gas is carried out by the method of low-temperature separations (LTS). 

For a natural gas field with methane content of more than 95% and small contents of heavy hydrocarbons, there is no need for such complex DCPGs. For such gas fields, the gas processing scheme needs only to ensure the separation and dehydration of gas. 

Another scheme of gas preparation on the gas-condensate field is presented in Fig. 1.2. In this scheme the process of low-temperature absorption (LTA) is used. 

S3 are separators Dl, D2 are three-phase dividers DA is the deflationer of the absorber DPC is a complex that includes a compressor of the turboexpander, an air refrigerator and a heat exchanger. The gas at the entrance to DPC has the pressure of 15 MPa and the temperature of 26.8 °C (Table 1.2). 

Before the entrance to separator SI, gas is throttled through Tl, achieving the pressure of 10.5 MPa and the temperatures of 15 °C. The separated gas leaving SI is then dehydrated in the absorber Al, and then, after consecutive compression in the compressor and cooling in the heat exchanger, enters the intermediate separator S2. The separated gas is further cooled in TEA as a result of performing work on the turbine and then moves to the bottom part of the contact chamber of 

---

Technological Schemes of Complex Oil, Gas and Condensate Processing Plants... 

---