Characteristics of Plasma Slotted Liner:
Structural characteristics——compound cavity
Every slot from outside to inside of the pipe consists of trapezoidal slot similar to rectangle with outside narrow and inside wide, transitional arc and another trapezoidal slot with one large angle.The outsidetrapezoidal slot is similar to rectangle with thickness 2~3mm. The angle of outside trapezoidal slot is very small, which weakens the corrosion ratio of oil with sand and therefore prolongs the service life of slotted liner. Because of the large angle of inside trapezoidal slot, the flow resistance of crude oil caused by the slot can be greatly reduced, which improves the efficiency of oil production. Plasma slotted liner has the advantage of "self-cleaning"
Mechanical characteristics---higher mechanical strength
Plasma slotted liner is slotted in water-base compound operating fluids by high-frequency plasma beam without heat stress,therefore no heat-affected zone like micro crack and blast of laser slotted liner,which makes the plasma slotted liner preserve higher mechanical strength.
Slot surface characteristics——better abrasion resistance and inoxidizability
When the plasma blaze with high frequency and temperature is processing the base pipe, the waterbase compound operating fluid produces electrolytic dissociation and thermal decomposition, whose production reacts with external metal material of liner.The surface of liner is simultaneously heated by the plasma blaze with high frequency. Consequently there generates a 0.1-0.2mm hardening and antiseptic layer on the processed surface of liner which can effectively prompt the abrasion resistance and inoxidizability of the slot.
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Fig 1. The transverse metallograph
reinforcement of plasma slotted liner
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Fig 2. The section view of the slot
surface of plasma slotted liner
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Slot processing characteristics——high accuracy of slot width
The slot width shows high accuracy and the tolerance is ±0.03mm. The smooth surface can be Ra 1.6 μm.
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Fig 3. The surface profile of plasma
slotted liner
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Fig 4. The surface profile of laser
slotted liner
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Application characteristics——self cleaning effect
Self cleaning effect is generally attributed to trapezoid slot shape, narrow at the surface and increasing in width at the interior, and the slot surface is smooth, which lets fine sands or shale easily enter without plugging. The larger sands blocked will sink as result of gravity to form permeable sand bridge to achieve the effects of external gravel pack.
Plasma Slotted Liner Specification
Plasma Slotted Liner OD
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Φ50- Φ219
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Length of Plasma Slotted Liner
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1000-12000
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Slot width
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Outside slot width
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0.15-0.5
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Tolerance
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±0.03
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0.6-4.0
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Tolerance
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±0.10
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Inside slot width
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Inside slot width+0.2mm
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Slot length
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Slot length
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According to customers" request
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Tolerance
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±1.00
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Slot quantities per circle
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According to customers`request
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Distance between the adjacent slots
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According to customers`request
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Application scope
It can be applied to the following well completion methods of horizontal well,side track well, branch well and gravel pack well completion:
■Slotted Liner SAS Well Completion
■Open Hole Screen Well Completion
■Open Hole Gravel Pack Well Completion
■In-Casing Gravel Pack Well Completion
■Slotted Liner Well Completion with External Casing Packer