|Base pipe||API casing or tubing|
|Slot style||Straight slot, keystone slot|
|Slot shape||Slotted or custom|
|Slot pattern||Staggered, straight in line, gang, or custom|
Slotted Liner Applications
Due to their ease of installation and lower costs when compared to well screens, slotted liners are a popular choice in many different production environments.
In consolidated formations, perforated and slotted liners with larger slots are run to stabilize the wellbore and provide a large flow area. These downhole characteristics are often present in geothermal wells.
In unconsolidated sand formations with gravel pack or large enough grain sizes, liners with slots of minimum width provide effective sand control and continuous flow of production fluids.
For example, Highdrilling slotted liners are often employed in the following production applications:
- Production of heavy oil and extra heavy oil (bitumen) in horizontal wells using extraction techniques such as CSS (cyclic steam stimulation) or SAGD (steam assisted gravity drainage).
- Production of coal bed methane (CBM) in horizontal wells.
Laser-Cut Slots for Highest Precision
Precisely sized slots are key to effective sand control. We achieve this precision by laser-cutting each slot instead of using saw machines. This way you can be sure that each slot is be placed on the liner exactly according to your slot design.
Another advantage of our laser cutting technology is that is not restricted to a limited range of slot dimensions, thus giving you maximum freedom in your slot design.
We are able to laser-cut slots as per customer specification, either as straight slots or keystone slots.
Cut at a right angle to the liner, this slot type shows the same diameter from the inside to the outside of the wall. Although straight slots are cheaper to produce, they are less effective in sand control compared to keystone slots.
Cut at a slight angle, keystone slots, or tapered slots, are larger on the inside than on the outside, making sure that any particle entering the slot can pass through freely without clogging the slot.
Keystone slots are more expensive to than straight slots, but lower the risk of production losses due to plugged liner slots.
Whether you want your slotted liner with a line, staggered, gang, overlapping, horizontal, or any other pattern, we can cut them all.
Among all slot patterns, the following three are the most common.
Line (Straight) Pattern
In the line pattern, slots are placed evenly in identical bands around the pipe, forming straight lines of slots across the length of the slotted liner.
Single-Slot Staggered Pattern
In the single-slot staggered pattern, bands of evenly spaced slots are placed around the pipe. Slots in different bands are offset (staggered) to each other.
The single-slot staggered pattern preserves the strength of the pipe and provides an even distribution of the slots over the area of the pipe.
Gang Pattern (Multiple Staggered Pattern)
While having the same overall layout as the single-slot staggered pattern, the gang pattern places two slots, cut at close proximity, instead of just one slot at each position.
Slotted liner with a multiple staggered pattern has been shown to withstand higher torque during installation and provide better resistance to deformation under thermal load compared to the single-slot staggered pattern, making it well suited for application in steam assisted gravity drainage (SAGD) applications.
Well Prepared for The Journey
After laser-cutting the slots, we take the following steps to ensure the consistently high quality of our slotted liner:
- Each joint is deburred and thoroughly cleaned from any remaining particles.
- To protect against corrosion during transportation and storage, each joint is firmly wrapped in waterproof cloth over the length of the pipe.
- Joints of slotted liner are securely bundled to prevent any form of damage during transportation.