Spacers and Flushes

One of the keys to successfully achieving zonal isolation is preparing the wellbore to receive cement.  This is done by using spacers to fully displace drilling fluid from the annulus and condition the casing and annular surface to accept a cement bond.  Spacers and flushes are intended to displace drilling fluid from the annulus, leave the casing and formation water-wet (free of oil), and separate drilling fluids from the cement slurry.  Thus, the spacer is pumped ahead of the lead cement slurry.  Flushes are used to thin and disperse drilling-fluid particles.

If even a thin layer of oil from the drilling fluid is left on the casing and/or the formation it can prevent the cement slurry from directly contacting each surface to form a good bond.  A properly conditioned hole has the best chance for a good cement job and the least chance of annular gas migration problems or costly remediation and squeeze cement operations.

The performance of a spacer mainly depends on

  • The rheology of spacer at the desired elevated temperature;
  • The compatibility of the spacer with the drilling fluid (mud) and the cement;
  • The volume of spacer necessary to provide sufficient separation of the cement from the mud to prevent the cement from becoming contaminated by the drilling fluid;
  •  Contact time and pump rate of the spacer to optimize drilling fluid displacement and removal.

Halliburton offers spacers and flushes to help operators improve the probability of returning uncontaminated mud to the surface and securing a successful primary cement job.

Attapulgite™ Additive
Designed for salt water applications, a colloidal clay mineral composed primarily of magnesium silicate, silica and crystalline quartz that functions as a suspending agent and can swell in salt water.
Dual Spacer™ E Spacer
Functions as a low viscosity, weighted flush for primary and secondary cementing operations, can be designed to displace water-based or oil-based muds, can be used at temperatures from 60°F (16°C) to 500°F (260°C).
Dual Spacer™ Mixing Aid Additive
Increases viscosity in the Dual Spacer system.
Dual Spacer™ system
Low viscosity, weighted spacer for primary and secondary cementing operations, can also be designed to displace water-based or oil-based muds.
Liquid Spacer Mix
A spacer fluid used to create SAM-4 well fluid, used between mud and cement slurries during displacement operations, helps reduce or eliminate the compatibility problems exhibited by other spacers, provides a spacer system that is temperature stable and has low fluid loss to the formation.
MF-1™Cement Thinner
A white, crystalline powder that can be combined with Morflo® III surfactant to create Mud Flush aqueous solution, helps prevent and break emulsions and water blocks.
Mud Flush™ III Powder
Acts as a dispersant for clay particles and as a water-wetting surfactant to chemically remove drilling mud and leave all downhole surfaces water-wet, has been environmentally evaluated according to OSPAR commission regulations.
PHPA™ Preflush
An oxidant that helps break up highly gelled muds for easier displacement, breaks down the backbone of polymers and reduces the effect of gelation.
Sepiolite
A complex magnesium silicate clay material that functions as a suspending aid in salt-water based spacers.
Super Flush™ Additive
A reactive fluid flush used before primary cementing to help improve mud displacement and cement bonding and helps control downhole fluid loss.
Tuned® Spacer E+ Cement Spacer
Environmentally acceptable cement spacer that can be formulated using fresh water, seawater or saltwater for optimum drilling fluid removal by effective control of the spacers yield point
Tuned® Spacer III Cement Spacer
A water-based spacer that is not limited to drilling fluid type, rheological properties can be designed for specific applications, can displace leading drilling fluid while eroding the filter cake.
Tuned® Spacer IV Cement Spacer
An optimized oil-based spacer system that is not limited to drilling fluid type, effectively displaces drilling fluid and erodes filter cake, preparing the formation for proper zonal isolation.
Tuned® Spacer V Cement Spacer
Spacer system developed for use at temperatures to 450°F (232.2°C), thermal stability of the extreme-temperature synthetic polymer allows modification of both the rheological properties and density at specific service temperatures.
Tuned™ Spacer Cement Spacer
Uses optimized rheology control to more thoroughly displace the drilling fluid.