Associated gas, also known as oilfield gas or petroleum associated gas, refers to natural gas produced together with crude oil during the extraction of oil. This natural gas is usually stored in the same trap structure as oil and often has similar geological origins. The main component of associated gas is methane, but it may also contain heavier hydrocarbons such as ethane, propane, butane, as well as non hydrocarbon components such as nitrogen and carbon dioxide.
The production and composition of associated gas may vary depending on the geological characteristics, extraction methods, and production stages of the oil field. In some oil fields, the production of associated gas may be very high, even exceeding the production of crude oil. In other oil fields, the production of associated gas may be relatively low.
Associated gas plays an important role in the process of oil extraction. Firstly, it is an important resource in the process of oil extraction and has significant economic value. Recycling and utilizing associated gas can provide additional sources of income for oil extraction companies. Secondly, associated gas can be used as a clean energy source for power generation, heating, and other fields, replacing traditional fossil fuels such as coal and oil, and helping to reduce greenhouse gas emissions and environmental pollution.
In the process of oil extraction, associated gas is usually collected through specialized gas collection systems and processed for utilization. The processing methods may include compression, liquefaction, purification, and other steps to meet the needs of different users. In some areas, associated gas may even be directly injected into underground reservoirs to enhance oil recovery.
In short, associated gas is an important resource in the process of oil extraction, with significant economic and environmental value. Through reasonable recycling and utilization, the maximum utilization of resources and sustainable development of the environment can be achieved.
The recovery method of associated gas mainly includes the following steps:
1. Gas gathering
Firstly, utilize gas gathering pipelines to collect associated gas from oil wells and production facilities. This step is the starting point for recovering associated gas, which is collected through a pipeline network to facilitate subsequent processing.
2. Compression
Next, use a compressor to compress the associated gas to a higher pressure. The purpose of compression is to reduce the volume of gas, facilitate storage and transportation, and also provide necessary pressure conditions for subsequent processing.
3. Dehydration
Then, remove water vapor from the associated gas through condensation or adsorption processes. The presence of water vapor in associated gas can affect its quality and utilization value, therefore dehydration treatment is required. The condensation method condenses water vapor into liquid water and separates it by lowering the temperature, while the adsorption method uses adsorbents (such as molecular sieves) to adsorb and separate water vapor.
4. Desulfurization
Desulfurization is a crucial step in removing sulfides from associated gas. The presence of sulfides not only causes corrosion of equipment and pipelines, but also affects the quality and utilization value of associated gas. Common desulfurization methods include amine method, oxidation method, adsorption method, etc. Among them, the amine method is widely used due to its high efficiency, stability, and renewable characteristics.
5. Stable
Stabilization treatment is the step of removing heavy components from associated gas to meet the specifications for pipeline transportation or sales. Through stable processing, the quality and stability of associated gas can be ensured, and its utilization value can be improved.
6. Conveying
Finally, the processed associated gas is transported to pipelines, storage facilities, or directly powered to consumer terminals. The choice of transportation method depends on factors such as the output of associated gas, transportation distance, and user needs. Common transportation methods include pipeline transportation, liquefied natural gas (LNG) transportation, and compressed natural gas (CNG) transportation.
In addition, there are some specific associated gas recovery methods, such as the application of complete sets of equipment for dismantling and recycling devices. This device has a small size, can be flexibly relocated, is convenient to use, and is easy to implement. It adopts a dismantling method to integrate natural gas compressors, refrigeration machines, auxiliary refrigeration systems and other related equipment together, achieving the recovery and liquefaction of light hydrocarbons in associated gas.
In summary, the recovery method of associated gas is a complex and systematic process that requires comprehensive consideration of multiple factors and selection of appropriate processes and equipment to achieve maximum utilization of associated gas.
