CONQOR 404 EH Phosphate-Based Corrosion Inhibitor | SLB


Phosphate-based corrosion inhibitor

Schlumberger Oilfield Services

At relatively low concentrations, the CONQOR 404 EH inhibitor is particularly effective against oxygen corrosion in aerated muds used in underbalanced drilling operations and low solids, nondispersed water-based fluids.


CONQOR 404 EH phosphate-based corrosion inhibitor is used for water-based drilling fluids, brine water systems and air, mist, and foam fluids. It is well suited for applications where calcium scale deposition is a problem, and it is especially effective in highly aerated fluids such as underbalanced drilling operations.

How it improves wells

  • Compatible with anionic foamers
  • Highly effective against oxygen corrosion caused by dissolved oxygen
  • Low toxicity
  • Minimum impact on fluids rheology
  • Effective in
  • fresh water or saturated saltwater
  • aerated fluids like those used in air-drilling operations
  • temperatures exceeding 350 degF [177 degC].

How it works

CONQOR 404 EH inhibitor is an all-purpose, water-soluble, organophosphate compound.

CONQOR 404 EH inhibitor is effective at relatively low concentrations such as 2.5 galUS/100 bbl [0.6 L/m3].

If the corrosion rate is unacceptably high, the concentration should be increased to at least 7 galUS/100 bbl [1.7 L/m3].
For aerated systems, an initial treatment of 12 galUS/100 bbl [2.9 L/m3] is recommended. The product should disperse throughout the circulating mud system and can be added either through the chemical barrel or directly to the mud pits, wherever good agitation occurs.

The corrosion rates should be monitored at all times with corrosion coupons. Treatments should be adjusted according to analysis. A good corrosion-control program includes a thorough makeup-water analysis, chemical treatments for corrosive contaminants, and an adequate bacterial control for systems that contain biodegradable additives.

Situations where it should not be used

  • Should not be used in packer fluids or situations where the fluid will not be circulated, nor on racked pipe.
  • Should not be used in formate brines or fluids.
  • Less effective when calcium exceeds 200 mg/L, increased product concentration required.

Toxicity and handling

Bioassay information is available upon request. Handle as an industrial chemical, wear protective equipment, and observe the precautions described in the Safety Datasheet.

Packaging and storage

CONQOR 404 EH inhibitor is packaged in 55-galUS [208-L] epoxy-lined steel drums and in 5-galUS [19-L] plastic pails. It is not a Department of Transportation-regulated material. Store in a dry, well-ventilated area. Keep container closed. Keep away from heat, sparks, and flames. Store away from incompatibles. Follow safe warehousing practices regarding palletizing, banding, shrink-wrapping, and stacking.

Typical Physical Properties

Physical appearance Clear yellow liquid
Specific gravity 1.43–1.44
pH of 5% solution 7–8.5
Flash point >200 degF [>93 degC]
Pour point –10 degF [–23 degC]

All specifications are subject to change without notice.