When reservoir fluid has a high free gas content at the pump intake, key parameters such as flow rate and pressure deteriorate significantly. In these cases, a gas separator is usually installed to recover pump efficiency and allow higher initial gas content in fluid.
Gas separators decrease the gas volume factor (GVF) to figures acceptable for the pump. Free gas in rotary gas separators is centrifugally accumulated near to center line and then channeled back to the casing annulus.
Another factor affecting successful ESP operation is abrasive wear due to high solids. As a result of abrasive wear, the protective liner and housing of a gas separator can be worn dramatically and sometimes even cut off by solids. When this happens, a part of the ESP system can detach and get lost.
Novomet designers have developed a brand new abrasion-resistant gas separator for the 362 and 406 series. The separators minimize vortex formation and recirculate flow structures. These separators were successfully proven during testing to have several times higher abrasion resistance than before. The separating ability of different designs was also simulated by CFD methods and then proven in full-scale tests.
Abrasion resistant gas separators (ARGS), currently available in two series:
- 362 series: N362GS1500 AR2 – for pumps with rated capacity up to 1500 bpd;
- 406 series: N406GS3800 AR2 and N406GS2600 AR2 – for pumps with rated capacity up to 3800 and 2600 bpd, respectively.
Upcoming abrasion resistant gas separators:
- 449 and 535 series
- High capacity ARGS N362GS4500 AR2 and N406GS6800 AR2
- protective liner from corrosion resistant Cr-Ni stainless steel
- axial thrust bearing in protector
- application of a shaft with involute splines leading to increased max brake horsepower
- bearing bushings from hard alloy
- corrosion resistant modification available
1. Application for complicated factors:
• high TSS (solid content) – up to 350 ptb
• high GVF at intake – up to 85%
• wells after hydraulic fracturing
2. Separation process was optimized by CFD methods, and extensive empirical study conducted at separation and abrasion test benches.
3. Design features of pressure and separating modules are unique and patented.
Multi-phase pumps enable continuous operation of ESP systems in fluid conditions with up to 65 % GVF at intake.
Submersible multi-phase pumps are designed to stabilize ESP system operations in fluid conditions with up to 65 % GVF at intake.
How does it work?
Multi-phase pumps provide a pressure increase at the pump intake, which enables stable system operations. It also pumps gassy fluid through the main pump, eliminating immovable gas locks. Each multi-phase pump stage disperses gassy fluid.
Design of the multi-phase stage has no left or right zones of flow stop. However, when the gas content at the pump intake exceeds 65%, the head created by the multi-phase pump decreases.
Multi-phase pump benefits
- Continuous operation of ESP systems in fluid conditions with up to 65 % free gas at intake.
- Free gas is used for gas lift effect to increase ESP head and efficiency.
- ESPs with a multi-phase pump operate without pressure pulsation, which stabilizes motor current diagram.
- Multi-phase pumps have higher abrasion resistance compared to regular pumps.
Multi-phase pump range
Novomet designed the following series of multi-phase pumps:
- 319 series (OD 3.19”) – 950 BPD;
- 362 series (OD 3.62”) – 1500 BPD;
- 406 series (OD 4.06”) – 950, 2400 and 3800 BPD.
- 272 series (OD 2.72”) – 950 BPD;
- 362 series (OD 3.62”) – 5300 BPD;
- 449 series (OD 4.49”) – 7550 BPD;
- 535 series (OD 5.35”) – 15000 BPD.
* Note: data given is for shaft rotation 2910 rpm