Polymer Flooding Operations, HSE, and Monitoring: A Practical, Short Technical Guide

Executive Summary

Polymer Flooding Operations, HSE, and Monitoring: A Practical, Short Technical Guide

Successful polymer flooding hinges on three pillars:
(1) disciplined operations (water quality, make-up/mixing, dosing, and injection ramp-up),
(2) robust HSE and logistics (safe handling, storage, and data governance), and
(3) continuous monitoring with actionable QA/QC (inline/lab viscosity, concentration, injectivity diagnostics, and production surveillance).

This note consolidates some field-tested practices including inline viscometry, Hall plots, and pressure fall-off (PFO) analysis—plus  polymer detection/concentration methods (refractometry, COD, bleach, UV, flocculation) and a time-phased QA/QC program from start-up through steady operations. It is a good start to build your own monitoring program.

Table of Contents

Scope & Objectives

Scope: Daily operations for polymer injection, on-site QA/QC, HSE controls, logistics, monitoring (injection & production), diagnostics for injectivity, and troubleshooting

Objectives:

    1. Achieve on-spec injected viscosity at reservoir conditions;

    2. Maintain stable injectivity and flow assurance;

    3. Detect and resolve off-spec events fast;

    4. Ensure safe handling and compliant operations end-to-end.

Operational Workflow (Day-to-Day)

Water Quality & Treatment

Target water chemistry (salinity, hardness, pH) and oxidant control are fundamental to polymer stability. Use nitrogen blanketing and/or deoxygenation /scavenger, iron control (chelants/filters), and maintain low dissolved oxygen to protect polymer from oxidative degradation (below 40ppb optimum).

Checklist—before make-up

  • Verify Dissolved Oxygen, Fe, oxidants, hardness, pH, salinity against spec.

  • Confirm filters are clean; 

  • Validate scavenger dosing & type if used.

Make-Up & Mixing Protocol

Calibrate scales/flowmeters, set correct stock concentration, ensure sufficient hydration, and avoid excessive shear (check pumps, static mixers, long recirculation loops). Watch for fish-eyes; improve powder wetting and agitation if present. Maintain temperature controls for consistent viscosity measurement.

Targets: Stable viscosity in the target brine and narrow concentration window; good filterability ratio (FR); absence of fish-eyes.

Dosing & Injection

  • Calibrate dosing pumps 

  • Inline viscometer or grab sampling to confirm injected viscosity under defined shear and temperature; align lab vs inline protocols.

  • Start-up strategy (vertical wells): fixed rate and increase viscosity gradually; if pressure limit is reached, reduce rates—not viscosity. For horizontal wells in secondary, shut producers, inject to fill-up & max pressure, then restart production and reduce injection rate by ~10–20%.

HSE & Logistics

Safe Handling & Storage

  • Powder polymer: minimize dust (closed transfer, local extraction), use PPE (respiratory & eye protection), store cool/dry; FIFO by batch (First In-First Out); prevent moisture pickup.

  • Emulsion polymer: avoid skin/eye contact; ensure adequate inversion energy; contain spills; segregate from oxidants.

Warehouse & Field Logistics

  • Certificates of Analysis (CoA) verified upon receipt; agree testing procedure/operator-supplier up-front; recognize that procedure + equipment can shift results—standardize

  • Sampling plan pre-approved with procurement; budget +30% buffer for extra samples during transients (rate/viscosity changes) or if disruptions expected (weather, repair, mainteance, etc.).

QA/QC Program

At factory / before shipment: per-batch filterability, yield viscosity, particle size distribution (supplier tests and shared procedures). Done by supplier: Certificate of Analysis.

At arrival (warehouse/site): review CoAs; perform batch analysis (viscosity, FR) on selected ones.

Start-up phase. First 3 months: two samples/week; additional samples during any major change.

Stable operations: one sample per week or biweekly.

Typical QC parameters (selected): filter ratio, specific consumption, viscosity in target brine, free-flowing properties, and coreflood (as needed).

Monitoring—Injection Side

Inline Viscometer (Non-Newtonian Context)

Inline devices estimate viscosity from pressure drop and flow through a calibrated tube under a power-law model adapted to polymer rheology. Standardize setpoints (shear rate/temperature), maintain clean lines, and correlate inline vs lab.

For manual sampling, make sure to use the proper device not to degrade the polymer solution (either mechanically or if oxygen ingress occurs).

Hall Plot for Injectivity Surveillance

Hall plots (cumulative pressure-time product vs cumulative injected volume, or simplified cumulative wellhead pressure vs volume) reveal changes in injectivity as slope changes. After reservoir fill-up, a straight-line slope is typical; curvature beforehand reflects rising pressure. Slope changes after viscosity adjustments can indicate fracture opening/closure.

Field learnings: If target rates cannot be met under matrix flow, limited in-zone fracturing may be necessary (as reported in polymer floods). Use step-rate tests, tracer breakthrough, logs, and geomechanics to differentiate matrix dilation vs fracture flow—especially in unconsolidated sands where “fracture geometry” is better viewed as matrix dilation and permeability enhancement under shear.

Pressure Fall-Off (PFO) for In-Situ Viscosity & Flow Regime

Polymer non-Newtonian behavior affects interpretation; use published PFO workflows to infer in-situ viscosity and near-wellbore behavior (matrix vs fracture/dilation). Reference methods and case studies (SPE 145125, 154376, 154832, 166085, etc.) to anchor analysis and design limits.

Monitoring—Production Side

KPIs & Time-Series

Track the following across primary, waterflood (WF), and polymer flood (PF) phases: cumulative oil, peak oil rate and response time to WF/PF, GOR/WOR evolution, average sustained oil rate/oil cut after response, early/sustained injection rates, and pattern throughput. Sudden WOR/GOR shifts or throughput collapse can flag conformance or injectivity issues.

Production Sampling – Polymer Detection & Concentration

Refractometry (RI)

  • Use: Fast trending on clean injection/produced water; calibrate in field brine.

  • Pros: Simple, cheap, quick.

  • Limits: Highly temperature-sensitive; salinity/ions shift baseline; oil/organics bias—pre-filter/de-oil.

COD (dichromate) in brine

  • Use: Quantitative when you can correct for chloride; lab setting.

  • Pros: Works across mid ranges; standard kits.

  • Limits: Chloride interference (needs removal/dilution); other organics/chemicals add non-polymer COD; hot digestion, consumables.

Bleach / starch-iodide (NaOCl, ~470 nm)

  • Use: Sensitive, low–moderate ppm on clean, de-oiled samples.

  • Pros: Inexpensive, good as a cross-check.

  • Limits: Oil, H₂S, organics, high Cl⁻ distort signal; time-sensitive kinetics; mainly suited to polyacrylamide backbones.

UV spectroscopy (≈207–217 nm)

  • Use: Rapid quant on filtered, de-oiled waters; 50–3,000 ppm typical.

  • Pros: Fast, good for trending; easy to automate.

  • Limits: Deep-UV absorbers (aromatics, surfactants, biocides) cause positive bias; needs stable optics/pathlength.

Kaolin flocculation test

  • Use: Qualitative yes/no (>~2 ppm) screen before quant methods.

  • Pros: Very quick triage.

  • Limits: False positives from other flocculants/chemicals; not quantitative.

Field rule of thumb

  • Always calibrate in field brine, control temperature, filter/de-oil samples.

  • Pair methods for cross-validation (e.g., UV + Bleach for produced water; RI + UV for injection water).

Troubleshooting

Injected Viscosity Off-Spec

Start here

  1. Polymer quality & identity (grade, batch, expiry, storage). If off → replace/correct.

  2. Sampling/measurement (method, equipment, calibration, temperature & shear). Align lab vs inline; recalibrate if mismatched.

  3. Make-up water (salinity/hardness, DO, oxidants, contaminants). Fix water treatment if out of spec.

  4. Mixing & dissolution (ppm setpoint, hydration time, fish-eyes). Correct protocol.

  5. Shear & degradation (pumps/mixers/loops). Reduce shear, redesign recirculation.
  6. Injection & transfer (plugged lines/filters, viscometer calibration). Clean/replace/re-zero.

Low viscosity—likely causes & fixes

  • Under-concentration → recalibrate dosing/dilution.

  • High salinity/hardness/oxidants → improve treatment, switch source, deoxygenate, remove Fe/oxidants.

  • Insufficient hydration → extend time, optimize mixing energy (without excess shear).

  • Degradation (shear/oxidation/thermal) → lower shear, remove oxidants, control temperature.

  • Contamination (e.g., biocide overdose) → isolate & flush, correct dosing.

  • Measurement mismatch → harmonize shear rate/temp; recalibrate instruments.

High viscosity—likely causes & fixes

  • Over-concentration → correct setpoints.

  • Low measurement temperature → warm to spec (e.g., reservoir temp).

  • Incomplete inversion (emulsion polymer) → raise inversion energy/residence time.

  • Fish-eyes → improve wetting/agitation; sieve if needed.

Polymer Dosage Anomalies

Verify pump calibration, leaks, dilution ratios, flow meters/scales, and check for blockages/bypasses. Align inline concentration/viscosity trends with lab confirmation; recalibrate and correct the faulty element.

“Other Problems” 

Scan for polymer change, abrupt water chemistry change, temperature spikes, pump failures, external contamination (oil/surfactant/biocide/bacteria), and instrument drift. Isolate samples, review logs, adjust water treatment, remove contamination sources, and recalibrate.

Data, Alarms & Field Communication

  • Dashboards with rate/pressure/viscosity/concentration targets;

  • Alarms (e.g., ±100 psi vs injection pressure target) dispatched to field ops, operations engineers, and reservoir engineers;

  • Weekly status reviews and a continuously maintained field activity log ensure alignment and rapid response.

You can also check our YouTube channel for additional videos and podcasts and navigate the Polymer Flooding Guide for more content or our Academy for training courses.