KLA-STOP

KLA-STOP additive is a liquid polyamine shale inhibitor used in polymer-based drilling and drill-in fluids. The additive inhibits shale or gumbo clays from hydrating and minimizes the potential for bit balling by preventing water uptake by clays and by providing superior cuttings integrity. It can be added directly to the mud system with no effect on viscosity or filtration properties.

Applications

The additive intercalates and reduces the space between clay platelets so that water molecules will not penetrate and cause shale swelling. Providing a buffered pH in the 9.0–10.0 range, it eliminates any required additions of caustic soda or potassium hydroxide.

Concentrations should be monitored using a filtrate amine titration method; recommended concentration is 1–4% by volume.

For reservoir drill-in fluid applications, compatibility with the reservoir should be evaluated through formation damage testing and filtrate/formation fluid compatibility testing.

It is important to monitor the cuttings condition at the shakers during drilling operations. Cuttings should be firm and dry inside. Sticky and balled-up cuttings may indicate insufficient inhibition from a low KLA-STOP additive concentration. The initial mixture may contain more KLA-STOP additive than specified in the mud program to act as a buffer against high consumption (e.g., 4%–5% by volume).

KLA-STOP additive can also be used as a shale inhibitor in gravel-pack fluids to maintain wellbore stability during high-rate water packs. The concentration is usually 1%–2% for this type of application.

Advantages

• Provides excellent shale inhibition and limits cuttings dispersion
• Reduces accretion potential and consequently bit and BHA balling
• Provides a buffered pH in the 9.0–10.0 range, eliminating any need for additions of caustic soda or potassium hydroxide
• Tolerant to common contaminants, including cement, hard water, CO₂, drill solids, and crude oil
• Environmental acceptability for both offshore and onshore applications
• Can be added to the active system without adverse effects on viscosity and filtration properties

Limitations

• May have reservoir formation or formation fluid incompatibilities; test for incompatibilities.
• May precipitate some salts out of brine solutions—test for precipitation.
• Do not use with aldehyde-based biocide.

Toxicity and handling

Bioassay information is available upon request. Handle as an industrial chemical, wearing protective equipment and observing the precautions as described in the safety data sheet.

Packaging and storage

The KLA-STOP additive is packaged in 55-galUS [208-L] drums. It is also available in bulk. Store in dry, well-ventilated area. Keep container closed. Keep away from heat, sparks, and flames. Store away from incompatibles.