Kosaka's screw pumps support operations in the offshore oil field.
Unlike onshore oil field facilities, space limited offshore oil field facilities are required to securely transfer multiphase flow from the viewpoint of "Simplification of facilities," "Reduction of operation cost" and "Securing of safety operation."
In such a situation, a multiphase pump to transfer multiphase flow as it is, is drawing attention.
Enabling transfer of not only fluids but multiphase flow of oil, gas and water
Twin screw pump excellent in transferring multiphase flow of water, gas and oil
A twin screw pump is a capacity type pump to raise the pressure by packing a given volume of fluid from the low pressure chamber into the high pressure chamber.
For this feature, compared to a centrifugal pump that gains pressure by giving speed energy to fluids, the twin screw pump is less affected by the viscosity of fluids and has the potential to raise the pressure of even gas-liquid multiphase flow containing almost gas (for example, gas volume ratio: GVF = approx. 95 %) and gain a relatively large discharge pressure.
The twin screw pump is originally good at handling multiphase flow.
Verification of twin screw pump
It is verified that even though the gas mixture ratio is increased, the performance is less degraded, when compared to a centrifugal pump.
On completion of being tested at the Kashiwazaki test field of the Japan National Oil Company Petroleum Development and Technology Center, this multiphase pump showed successful results of the demonstration test at the field of the United Petroleum Development Co., Ltd., which is doing oil field operation in the Middle East region to get a high evaluation (Implemented in 2000).
Specification for the "Twin screw pump" used for demonstration experiment
| Type | TH75MH |
|---|---|
| Volume of fluid handled | 36.4 m3/h (GVF 0 %), Diff.Prs. = 600 psi |
| Approx. 3m3/h (GVF 90 %), Diff.Prs. = 350 psi | |
| Suction pressure | 0.69 MPa（100 psi） |
| Absorption pressure | Max. 4.83 MPa (700 psi) |
| Discharge pressure | Normally 3.10 MPa (450 psi) |