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Slotted Liner 101

Different types of oil need different types of equipment. Heavy oil is found in parts of the United States, Canada, Columbia, Venezuela, Mexico, Abu Dhabi, China, Russia, Australia, and Africa. Heavy oil is filled with sand and other sedimentary material. The slotted pipes are used to filter more than 98% of the sand out while the well is being pumped.

Straight vs. Seamed Slot:
RGL produces two styles of slots: straight and seamed.
Straight slots are the first type of slots created in liners, and they are cut with equal width through the wall of the pipe. Specified where sand grain bridging at the slot is not of major importance, straight slots are more wear-resistant than seamed slots and are less costly to produce.
Seamed slots are milled wider on the pipe interior and are self-cleaning to help prevent plugging. They are narrow at the liner surface and increase in width at the interior, letting sand that does enter pass easily through the slots without plugging. RGL’s equipment has the capability to produce seamed slotting at an angle of 6°.

The width of the slots should be some two to three times the diameter of medium-sized sand particles. Our slots range in width from 0.010 (10,000th) of an inch up to 0.250 (one quarter) of an inch.
Slot lengths are precision-cut at high production rates, and they can be matched to your precise specifications in lengths of 1.5 to 2 inches, depending on slot width.

Unless otherwise specified, slotted liners are cut with an even number of rows. This enables the rows to be staggered to preserve most of the pipe's original strength and to maintain a 3% open area. When slots are evenly distributed over the pipe surface, drainage is more efficient.

  1. 1.5 inches in length on the interior diameter for slot widths up to 0.028 inches.
  2. 2.0 inches in length on the interior diameter for slot widths from 0.038 to 0.250 inches.
  3. 2.0 inches in length on the interior diameter for slot widths from 0.025 to 0.028 inches are available on request.

The number of slots per foot of pipe is determined by calculating the number required to achieve the necessary percentage of open area on the pipe's outer surface.  

See our Open Area Calculator to determine open area based on your specifications. For assistance in determining your ideal slot pattern, please contact us.

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