PAM-S Polymer Mud for Sand StrataNPT-PAM-S
A film-forming wall-protection material designed for highly permeable sand strata — reducing slurry loss into the formation and ensuring borehole-wall stability and hole quality.
Product Overview
One-liner: Film-forming wall protection for sand, A film-forming wall-protection material designed for highly permeable sand strata — reducing slurry loss into the formation and ensuring borehole-wall stability and hole quality.
PAM-S is Neptune’s film-forming polymer mud developed for highly permeable sand strata, forming a dense film across sand pore surfaces and keeping slurry loss within acceptable limits for drilling. It dissolves quickly in water; after entering the hole it forms a continuous mud film on the sand surface within 30–60 minutes, inhibiting fines migration while reducing slurry loss into the formation and ensuring borehole-wall stability and hole quality. Widely used in water-rich sand shield tunnelling, cross passages and pile foundations.
Fast film forming
Forms a continuous mud film on the sand surface within 30–60 minutes of entering the hole, inhibiting fines migration.
Low loss
Measured loss below 2 L/min (Φ1200 hole, 80 m sand section).
Low dosage
20–30% less than conventional polymers, keeping overall cost per hole in check.
Applicable Strata / Scenarios
| Strata type | Typical scenario | Recommended ratio | Expected effect |
|---|---|---|---|
| Fine sand / silty sand | Bridge piles, metro pile foundations | 1 : 400 | Stable wall, no slurry loss |
| Medium-coarse sand / gravelly sand | Large-diameter drilling, piling rigs | 1 : 300 | Fast film, fewer reworks |
| Running sand / gushing sand | Shield crossing, cross passages | 1 : 250 (thick slurry) | Surface settlement < 3mm |
| Sand interbedded with pebbles | Composite strata transitions | 1 : 350 | Prevents transition collapse |
Technical Data Sheet
Quantified core indices for product selection and tender comparison; a test report ships with every batch.
| Test item | Specification | Test method |
|---|---|---|
| Appearance | White / pale yellow uniform powder, free of caking | Visual |
| Solids content | ≥ 98.0% | Oven drying at 105℃ |
| Fineness (residue on 80-mesh sieve) | ≤ 3.0% | Sieving |
| Viscosity (1% solution, 25℃) | ≥ 1200 mPa·s | Rotational viscometer |
| Loss rate (Φ1200 / 80 m sand section) | < 2.0 L/min | API-standard field measurement |
| Fluid loss (7.5 min / 0.7 MPa) | ≤ 8.0 mL | Ambient fluid loss |
| Packaging | 25 kg / bag; jumbo bag optional | — |
How to Use / Mix Design
| Step | Key points | Reference dosage |
|---|---|---|
| 1. Make-up | Add slowly to clean water at the specified ratio; stir for 15 minutes until fully dissolved | 1 : 300 ~ 1 : 400 |
| 2. Circulation | Circulate in the mud pond for 1–2 tanks before drilling; watch the returns | Returns ≥ 90% of input |
| 3. Adjustment | When loss increases, thicken in 5% steps — never adjust by a large ratio at once | +5% each time |
| 4. Wrap-up | After the hole is completed, displace with clean water or proceed straight to cage lowering | — |
Related Solutions
01Sand Strata Construction Solution
A full material and process package from mix design to loss control, holding surface settlement under 3 mm in water-rich sand.
04Slurry Loss Emergency Response Plan
An emergency response flow for sudden slurry loss and collapse warning signs — plugged within 2 hours and back to work fast.
Related Cases
East · Metro / shieldWater-rich sand cross passage: 3 mm settlement, 6 days ahead
A metro cross passage in East China crossed water-rich fine silty sand. With high permeability, plain bentonite slurry lost over 15 L/min; the failed wall triggered surface settlement and a 5-day stoppage on a schedule-critical section.
Project scaleOne metro cross passage on the line's critical path, beneath a city road
Southwest · Bridge pilesPile drilling through pebble strata: 100% hole acceptance
Main-pier piles of a major bridge in Southwest China crossed deep pebble beds with stones over 800 mm. Φ1500 holes shrank to Φ1380, blocking cage installation, and bottom sediment ran thick — more than 4 clean-out passes per pile.
Project scaleMain-pier piles at Φ1500 mm through pebbles over 800 mm
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