Losseal Microfracture Lost Circulation Control Treatment | SLB

Losseal Microfracture

Lost circulation control treatment

Losseal Microfracture

Losseal Microfracture lost circulation control treatment combines specific engineered fibers with optimally sized solid bridging materials to increase the effective solid volume fraction (SVF) of carrier fluids such as muds, spacers, and cements. Losseal Microfracture treatment works in both water- and oil-based systems.

The result is a compact, impermeable seal that plugs pores and fractures and mitigates the risk of lost circulation during drilling, casing, and cementing operations. During drilling and precementing, the Losseal Microfracture treatment is applied through a pill. During cementing operations, the Losseal Microfracture treatment is directly added to the spacer fluid ahead of the cement.

By using the Losseal Microfracture treatment, operators regain circulation or prevent lost circulation, run casing without losses, and achieve required top of cement, substantially reducing NPT and costs.

The treatment contains inert and fibrous material and has been thoroughly field proven to pass through 8/32-in [6.35-mm] bit nozzles and can plug slots as small as 1/16 in—eliminating the need to pull out of hole. The Losseal Microfracture treatment has been successfully used in more than a 1,000 treatments across North and South America.

Handful size sample of the Losseal Microfracture treatment which creates a compact, impermeable seal that plugs pores and fractures
The Losseal Microfracture treatment creates a compact, impermeable seal that plugs pores and fractures.


  • Drilling, casing, and cementing operations with losses less than 40 bbl/h
  • Microfractured formations with fracture widths less than 1 mm
  • Weak zones and depleted formations


  • Reduces NPT by
    • Mitigating the risk of cement and fluid losses
    • Curing losses without setting cement plugs
    • Eliminating the need to POOH by pumping through bit nozzles as small as 1/16 in
    • Helping regain circulation quickly
    • Achieving required TOC
  • Eliminates time-consuming, expensive remedial operations


  • Mixes with cement, spacer fluids, and water-, oil-, and synthetic-based muds
  • Combines an interlocking network of fibers with sealing material of various sizes
  • Ranges from 5 to 15 lbm/bbl fiber concentration depending on SVF
  • Easily disperses in fluids
  • Eliminates special equipment and laboratory tests
Illustration of how the Losseal Natural Fracture treatment creates an impermeable seal to cure losses.

The Losseal reinforced composite mat pills family

The Losseal reinforced composite mat pills family uses an innovative blend of fibers and sized solids to bridge and plug thief zones that can lead to lost circulation while drilling and cementing. Treatment using the Losseal family meets the demands of a wide range of environments including natural fractures, dolomite and carbonate zones, rubble zones, depleted reservoirs, and reservoirs with known lost circulation issues.The reinforced composite mat pills can be pumped through BHA nozzles as small as 8/32 in—eliminating the need to pull out of hole.

Create an impermeable grid against losses

The Losseal reinforced composite mat pills family creates a strong, impermeable grid that stops fluids from flowing into high-conductive zones. The grid is designed to withstand additional pressure from wellbore dynamic pressures and fluid density increases, and any future drilling or cementing operations. Treatment using these reinforced composite mat pills saves thousands of barrels of fluid during circulation or placements and reduces NPT caused by lost circulation.

Seal off thief zones without detailed measurements

Traditional lost circulation materials are often successful for a fixed pore or fracture opening. The Losseal family is much less sensitive to fracture sizes or variation in fracture sizes and can be applied without detailed formation measurements.