Development of gas fields is associated with specific features and a number of requirements for the organization of the process. The reservoir pressure available at the time of the start of field development is sufficient to transport gas from the well to the main treatment unit and the gas pipeline without the use of compressor equipment. However, the reservoir pressure gradually drops during the production process, as a result of which there may be a lack of pressure to supply gas to the gas pipeline. For this reason, the development of the field, from a technological point of view, is divided into two stages - non-compressor and compressor. They differ in the use of a compressor unit, which allows increasing the pressure of the produced gas. Such equipment is called booster compressor stations. I use them to solve the following problems:
- Low pressure gas production.
- Compression of associated and petroleum gas for further transportation.
- Maintain a specific outlet gas pressure.
- Purge, cleaning and pressure testing of pipelines.
Regioncompressor applications
An important component of field development is the compressor stage. The selection of 50-60% of the total gas reserves is carried out during the non-compressor stage, while the compressor mode allows you to extract an additional 20-30% of the total reserves. The equipment used for gas preparation is designed to operate under a certain pressure, under which the gas will subsequently be supplied to the main gas pipeline. When the pressure of natural gas drops, the booster compressor ensures its stability by increasing the pressure by the required amount. Thanks to this, booster stations are considered the most important equipment for gas production.
Booster compressors, or boosters, are installed not only on wells, but also on underground gas storages, where they are used to extract gas from the storage and then supply it to the gas pipeline under the required pressure. The reverse procedure - gas extraction and its injection into the storage facility - is carried out by the same compressor station. The equipment must develop a high outlet pressure, otherwise the volume intended for storage will be used irrationally. Underground storage facilities built in solid rock can store gas at pressures ranging from 0.8 to 1 MPa.
Design and principle of operation
Booster compressors may vary in configuration and design, but they have several basic elements:
- Drive.
- Compressor block.
- Optional equipment.
Forthe increase in gas pressure corresponds to the main component of the booster compressor - a compressor or a group of compressors. It is driven by a drive connected to it. Auxiliary equipment means any devices that ensure the correct operation of the station - cooling systems, oil circulation, a set of instrumentation and others. The station, represented by a separate module, can be equipped with lighting, heating, ventilation and other systems.
Classification
The key element of booster compressor stations is the compressor unit, which provides movement and injection of gas. Classification of stations is carried out depending on the type of compressors used:
- Piston.
- Screw.
- Centrifugal.
Reciprocating compressors
Reciprocating booster compressors are positive displacement. The principle of their operation is based on the reduction of the volume of the working chamber created by the cylinder and the movable piston, and in which the gas is compressed. The advantages of such models are simple design, which facilitates repair and maintenance, reliability and unpretentiousness. In comparison with analogues, reciprocating compressors develop a large gas pressure. The reverse side of these advantages is the non-uniformity of the gas flow, caused by a cyclic change in the volume of the working chamber, which is associated with the reciprocating operation of the piston. In addition, such compressors are subjected to vibration loads and are noisier. Booster stations equipped withreciprocating compressors have similar features. They are easy to operate, affordable, and can compress gas to high pressures. Compact models can be placed on the receiver, while large models require large and stable platforms.
Screw compressors
A screw booster compressor is also classified as a volumetric model, but its working chambers are formed by cutting off the required space with screws and the compressor housing, linked together. Unlike reciprocating compressors, they develop high pressure and do not require the creation of a multi-stage gas compression system. Screw compressors are structurally more complex and expensive in comparison with similar compressors, but at the same time they are simple and reliable in operation with strict observance of all maintenance and operation standards. Compact dimensions and minimal noise level make it possible to use screw gas booster compressors in mobile stations, but at the same time they are also installed in large booster compressor stations in high-tech enterprises, since they create a smooth gas flow without pulsations characteristic of reciprocating compressor stations.
Centrifugal compressor
The gas pressure in a centrifugal oxygen booster compressor is increased by imparting kinetic energy to its flow, which is subsequently transformed into potential pressure energy. The transfer of kinetic energy is carried out from the rotating blades of the workingwheels, while its transformation takes place in the diffuser, at the outlet of the compressor. This method of gas compression is called dynamic. Unlike screw and piston compressors, centrifugal compressors do not create such a high pressure, which is why they are made multi-stage in order to achieve the required compression value. But at the same time, such booster compressors for nitrogen and gas and similar stations provide a large gas flow rate, which makes them most in demand at gas producing fields, enterprises and other places where large volumes of gas are required. The centrifugal compressor discharges gas evenly, making it much easier to pump.
Classification by drive type
The type of fuel used for the operation of booster compressors depends on the type of drive used in the compressor stations. The possibility of supplying fuel is decisive, since such equipment is often installed in hard-to-reach places and at a distance from transport routes. The most commonly used drive types are:
- Gas engine.
- Gas turbine.
- Electric.
Gas engine drive
Gas engine drive is based on an internal combustion engine that uses gaseous fuel - one of the cheapest and most affordable sources of energy. Such models are unpretentious in operation and reliable. The drive is started with compressed air, and changing the gas supplied to the cylinders allowsadjust the speed.
Gas turbine drive
The generation of mechanical energy in a gas turbine drive occurs with the help of a turbine, in which the hot gas formed in the combustion chamber expands. The compressor sucks in air, which is why the gas turbine drive requires the installation of a separate energy source - a starter. The combustion chamber, compressor and turbine are the main structural components of a gas turbine device. This type of drive is in demand, because it does not need third-party fuel and runs on gas pumped by a booster station. Surplus generated energy can be used to supply electricity and heat both the station itself and nearby facilities.
Electric drive
Booster compressor stations equipped with electric drives have certain advantages over gas turbine and gas engine counterparts, despite the need for electricity supply. The use of electric power saves on pumped fuel and increases the environmental friendliness of stations due to the reduction of emissions of harmful substances into the atmosphere. Adjustment and automation of the electric motor is much easier, which greatly simplifies the maintenance and control of the entire station and reduces the number of operating personnel. Eliminating vibration, noise and dust content in the air improves working conditions at such booster compressor stations.
