Whilst the oil and gas industry is one that has been getting less spotlight in recent years due to developments in green energy, it is still a critical industry employing millions of people around the world and using millions of CFM of compressed air.
This subject matter is one that can get very technical, with terminologies commonly heard like onshore, offshore, upstream and downstream, and global variants, differing descriptions and standards – for example the North Sea commonly uses Zone 2, Gulf of Mexico Rigsafe and Scandinavia typically refer to the NORSOK standard. All are equivalent standards but named differently and it can be a little confusing to keep up with.
Let’s keep it simple and provide an understanding of oil and gas basics.
There are many applications for compressed air throughout the oil and gas business, however this blog focuses on the main areas covering onshore and offshore applications.
Typical offshore applications:
- Well Completion & Testing
Typical onshore applications:
- Well Completion & Testing
- Nitrogen Spreads and Foam
Upstream and downstream explained
Upstream and downstream oil and gas production refer to an oil or gas company’s location in the supply chain. Upstream oil and gas production is conducted by companies who identify, extract, or produce raw materials. Downstream oil and gas production engages in anything related to the post-production of crude oil and natural gas activities.
- Upstream: finding, extracting, drilling, production and shipping
- Downstream: refine to exacting finished products then petrol station as you would identify
Onshore Drilling – drill rigs can be powered by air compressors, diesel generators and hydraulic motors. The benefit of using air powered rigs is:
- You can turn off the compressor when the rig is not drilling or active.
- You can utilize the air for cutting extraction, drill cooling and winch drawback work.
Air drilling made simple
- Air Drilling – gases (compressed air or nitrogen) are used to cool the drill bit and lift cuttings out of the wellbore. This allows for much faster drilling than drilling with liquids (mud).
- Underbalanced Drilling – the wellbore pressure is deliberately kept below the hydrostatic head pressure of the formation being drilled. With this technique oil can be produced from a well as it is being drilled. Techniques – Dry air gas (aka “Dusting”), Mist drilling, Foam or stiff foam, Aerated fluid.
- Multipurpose Drilling - minerals, water, geothermal, onshore and offshore etc.
Well completion and testing
The purposes of a well completion is to:
- Connect the reservoir to the surface so that fluids can be produced from or injected into the reservoir
- Provide a conduit for well stimulation treatments
- Isolate the producing reservoir from other zones
- Protect the integrity of the reservoir, especially in unconsolidated formations
- Provide a conduit to measure the changes in flow rate and pressure needed to run a well test
Examples of air in oil and gas applications
Typically, air is used in several ways in both offshore and onshore oil and gas applications. The requirements can vary from low to high pressure and flow depending on its use. Below are some examples:
- Rig Air – used for air powered hoists, tools, winches, clutching operations for main draw works, and for top drive drilling system
- Bulk Air - to convey dry cement for casing the drill hole, or to convey dry mud for drilling operations
- Emergency Air - Survey regulations demand that an emergency compressor be permanently on board that is totally independent from other systems; typically called “black start” or “dead ship” compressor
- Motion Compensation - the drill string usually has an air motion compensator that negates the effect that the platform has on the drill string due to motion
- Offshore Platforms – instrument panels, air operated equipment (engine starters, hoisting systems, etc), flare gas inerting, well head testing, etc.
- Storage & Transportation – nitrogen is used to inert storage facilities, storage tanks, and cargo holds of vessels (ships or barges), as well as train/truck mounted storage facilities
- Gas Assist Lift – promotes greater oil and gas production from the wells
- Refinery Shutdowns – all sizes and small to large capacity “temporary” power, oil lubricated and oil free air
- Drilling – water, minerals, oil etc.
- Well Workovers – frac nitrogen revitalizes new or existing wells that have poor production rates
- Coiled Tubing – widely used in downhole control and monitoring in intelligent well completions, and chemicals injection using acids, surfactants and methanol
- Fabric Maintenance – ongoing site repairs
Solutions to fit every oil and gas need
Sullair have a vast and variable product range covering the large spectra of oil and gas applications such as offshore, onshore, upstream, downstream, oil flooded, oil free to name but a few. From portable requirements of as little as 185 cfm to the large OFD1550 or even the two-stage high pressure compressors, our product range covers all applications. Our stationary range can be found in the smallest shop blasting sheds or out of sight on an FPSO* (Floating Production Storage and Offloading Vessel). The above is only the tip of the iceberg.