CP-31 is a self-activating organophilic clay viscosifier developed for oil-based drilling fluid applications where the absence of external chemical activator is required or preferred. Its engineered surface modification enables spontaneous gel development in synthetic base oils, low-aromatic mineral oils, and white oil systems — without the propylene carbonate, ethanol, or other polar activators that conventional OBM organoclay grades require. CP-31 is particularly valuable for low-shear mud plant operations, well-site completion fluid manufacture, and cold-climate drilling where activator handling is difficult or where rapid, reliable yield development is critical.
Technical Properties
| Parameter | Specification | Test Method |
|---|
| Chemical composition | Organically modified bentonite clay | — |
| Appearance | Off-white to tan free-flowing powder | Visual |
| Moisture content | ≤ 4.0% | 105°C, 2 hours |
| Particle size | ≥ 95% passing 76 μm (200 mesh) | Sieve analysis |
| Activation requirement | Self-activating — no external activator needed | — |
Performance Advantages
- Rapid yield development — reaches target yield point faster than activated conventional grades; reduces wait time during mud mixing
- High gelling strength — effective yield point and gel structure at standard treat rates (5–15 kg/m³)
- High slurrying efficiency — disperses uniformly in base oil under standard rig-site mixing conditions
- High thermal stability — maintains rheological performance at elevated bottom-hole temperatures
- Eliminates external chemical activator — simplifies mud mixing procedure; reduces chemical inventory; eliminates activator-related handling and VOC issues
- Easy dispersing — effective in low-shear mixing equipment; suitable for jet-hopper addition
- Good low-temperature incorporation — develops gel at sub-zero and cold-temperature conditions; valuable for Arctic and cold-climate operations
Compatible Base Fluids and Applications
| Base Fluid | Application | Typical Treat Rate |
|---|
| Low-aromatic mineral oil (LTOBM) | Offshore environmental compliance OBM | 6–15 kg/m³ |
| Synthetic base oil (IO, LAO) | Synthetic-based mud offshore/deepwater | 6–15 kg/m³ |
| White oil / medical-grade mineral oil | Completion fluids, packer fluids | 5–12 kg/m³ |
| Diesel oil | Standard OBM, invert emulsion | 5–14 kg/m³ |
| Mineral oil (standard) | All-oil system, invert emulsion | 5–14 kg/m³ |
| Crude oil | Workover, well completion | 5–12 kg/m³ |
Low-Shear and Cold-Weather Advantage: Conventional OBM organoclay requires high-shear mixing and external activator addition in a specific sequence to achieve full gel development. In low-shear mud plants, cold climates, or field completion operations where mixer capacity is limited, conventional grades frequently underperform — insufficient activation leads to inadequate yield point and poor barite suspension. CP-31's self-activating property eliminates this risk, providing reliable performance in the most challenging mixing conditions.
Incorporation Method
- Add CP-31 directly to base oil through jet hopper or mixing system — no activator required before or after addition
- Mix at available shear for minimum 15 minutes — CP-31 is effective even under low-shear conditions
- Check initial rheology before adding emulsifiers — ensure target yield point is reached before proceeding
- Add emulsifiers and other additives after CP-31 is dispersed
- Complete mud formulation and verify final rheology before weighting up
Frequently Asked Questions
What makes CP-31 self-activating in drilling fluids?
CP-31's surface modification allows spontaneous gel development in oil-based drilling fluids without an external activator. This simplifies mud mixing, reduces chemical inventory, and eliminates under-activation risk in low-shear or cold-weather conditions. Compare to CP-982 and CP-992 which also work without external activator in drilling fluids — CP-31 is additionally optimized for synthetic and low-aromatic base fluids with good cold-temperature performance.
What base oils is CP-31 compatible with?
CP-31 is specifically suited for low-aromatic mineral oil (LTOBM), synthetic base oils (internal olefins, linear alpha olefins), and white oil base fluids — where conventional grades may need higher treat rates. Also effective in diesel, crude oil, and standard mineral oil OBM systems. All invert emulsion fluid types, workover fluids, completion fluids, packer fluids, and spotting fluids.
How does CP-31 perform at low temperatures?
CP-31 has good low-temperature incorporation properties — develops effective yield point when mixed in cold-weather conditions (down to approximately −10°C surface temperature). This is critical for Arctic drilling, Siberian operations, and offshore North Atlantic locations where conventional organoclay with liquid activator may suffer incomplete activation. Also valuable for well-site completion fluid manufacture where heated mixing is not available.
Thermal stability guide → Packaging and Storage
| Parameter | Specification |
|---|
| Standard packaging | 25 kg kraft paper bags with PE inner liner |
| Shelf life | 2 years from manufacture date |
| Storage conditions | Dry, covered warehouse; protect from moisture and direct sunlight |
Related grades: CP-982 (standard OBM, requires activation) ·
CP-992 (wet process, rapid yield) ·
CP-34 (coatings + drilling dual-use)
Related applications: Oil-Based Drilling Fluids ·
Viscosity Control in OBM ·
North Sea Drilling ·
Russia Arctic Drilling
