Enhanced Oil Recovery (EOR)

PAM Polymer Flooding for Enhanced Oil Recovery

Conventional waterflooding recovers 30-40% of original oil in place (OOIP). Polymer flooding with PAM pushes that to 45-55% — an additional 10-15% OOIP. At $70/barrel, a 100 million barrel reservoir gains $700M-1.05B in recoverable value from polymer flooding. We supply EOR-grade PAM to operators in the Middle East, Southeast Asia, and Central Asia.

The mechanism is simple: PAM increases injection water viscosity, improving the mobility ratio between water and oil. Water no longer fingers through high-permeability channels — it sweeps the reservoir more uniformly, pushing more oil to production wells.

How Polymer Flooding Works

Mobility Ratio Improvement

Mobility ratio M = (water mobility) / (oil mobility). When M > 1, water fingers through the reservoir, bypassing oil. PAM at 500-2000 ppm increases water viscosity 5-20x, reducing M below 1 and forcing water to sweep more uniformly.

• PAM concentration: 500-2000 ppm in injection water
• Viscosity increase: 5-20x at 1000 ppm
• Molecular weight: 15-25M Da (high MW for viscosity)
• Hydrolysis degree: 25-35% (for salinity tolerance)

Reservoir Conditions

PAM polymer flooding works best in:

• Sandstone reservoirs (limestone adsorbs too much PAM)
• Permeability >50 mD (low-perm reservoirs plug)
• Temperature <90°C (standard PAM), <120°C (AMPS-modified)
• Salinity <50,000 ppm TDS (standard), <200,000 ppm (salt-tolerant grade)
• Oil viscosity 5-200 cP (heavy oil needs higher PAM concentration)

EOR Grade Selection

Case Study: Sandstone Reservoir, Middle East

Injection System Design

PAM polymer flooding requires careful injection system design to avoid mechanical degradation:

1. Dissolution: Dissolve PAM powder in fresh water at 0.5-1.0% concentration. Use low-shear mixing (30-60 RPM) for 2-4 hours. Never use high-shear pumps — they break polymer chains.
2. Maturation: Allow 4-8 hours for full hydration before injection. Partially hydrated PAM has lower viscosity and higher adsorption.
3. Dilution: Dilute to injection concentration (500-2000 ppm) with produced water or seawater. Use inline static mixers, not centrifugal pumps.
4. Injection: Use progressive cavity pumps or reciprocating pumps. Centrifugal pumps degrade PAM by 20-40% per pass.
5. Monitoring: Check viscosity at wellhead weekly. Viscosity drop >20% indicates mechanical degradation or bacterial attack.

Our EOR-Grade PAM

EOR applications demand the tightest specifications in the PAM industry. Our EOR grades:

• MW: 20-28M Da (±0.5M tolerance)
• Hydrolysis: 25-35% (±2% tolerance)
• Filterability ratio: <1.5 (critical for injectivity)
• Residual monomer: ≤0.05%
• Insoluble content: ≤0.1%
• Dissolution time: ≤90 minutes

Filterability ratio is the most important EOR-specific parameter — it measures how easily the polymer solution passes through reservoir rock. A ratio above 2.0 causes injectivity decline and plugging. We test every EOR batch for filterability before shipment.

Frequently Asked Questions

How much PAM does a typical polymer flood project consume?

A 1,000 barrel/day injection well at 1,500 ppm PAM concentration consumes approximately 240 kg/day of PAM powder. A 10-well pattern project consumes 2,400 kg/day — about 876 tons/year. We supply annual contracts for EOR projects with guaranteed pricing and delivery schedules.

What happens to PAM in the reservoir?

PAM adsorbs onto rock surfaces (50-200 µg/g rock), reducing effective permeability and improving sweep. The remainder flows through the reservoir and is produced with oil and water. Produced PAM is biodegradable and does not accumulate in the environment.

Can PAM polymer flooding work in carbonate reservoirs?

Carbonate reservoirs (limestone, dolomite) adsorb 3-5x more PAM than sandstone, making polymer flooding uneconomical in most cases. For carbonates, we recommend surfactant-polymer flooding or alkaline-surfactant-polymer (ASP) flooding, which reduces adsorption. Contact us for carbonate-specific recommendations.