Overview
ISO 13503-5:2006 - "Petroleum and natural gas industries - Completion fluids and materials - Part 5: Procedures for measuring the long‑term conductivity of proppants" defines a standardized laboratory procedure to evaluate the long‑term hydraulic conductivity of proppant packs used in hydraulic fracturing and gravel‑packing operations. The standard provides a repeatable methodology for measuring proppant pack width, differential pressure, temperature and flow rates over time to calculate permeability and conductivity under controlled conditions. Note: the procedure is not intended to yield absolute downhole conductivities.
Key topics and technical requirements
- Test objective and limitations
- Measures long‑term proppant pack conductivity in laboratory conditions; does not represent absolute downhole behavior.
- Emphasizes single‑phase, laminar flow and avoidance of non‑Darcy/inertial effects.
- Test fluid and materials
- Standard test fluid: 2% by mass KCl in deionized/distilled water, filtered to ≥7 µm; KCl ≥99.0% purity.
- Recommended sandstone: Ohio sandstone cores with tightly specified dimensions and surface tolerances.
- Apparatus and construction
- Linear‑flow test unit with a standard proppant/bed area (documented bed area).
- Pistons and chambers: corrosion‑resistant alloys (e.g., 316 stainless steel, Monel, Hastelloy); filters typically Monel wire cloth (~150 µm, 100 US mesh).
- Hydraulic load frame capable of targeted closure stresses (specified capacity and accuracy) with parallel platens and controlled loading rates.
- Procedures and measurements
- Apply closure stress and hold for 50 h ± 2 h at each stress step to reach semi‑steady state.
- Use multiple flow rates per stress level; measure pack width (accuracy ~0.0025 cm / 0.001 in), differential pressure, temperature, and flow.
- Calculate permeability and conductivity from measured pressure drop and pack geometry.
- Quality and controls
- Equipment calibration, leak tests, oxygen removal, silica‑saturation monitoring, and data reporting are specified to ensure reproducible results.
Applications and users
ISO 13503-5:2006 is used by:
- Proppant manufacturers for product qualification and comparisons.
- Petroleum service companies and testing labs performing proppant evaluation and R&D.
- Completion and reservoir engineers assessing proppant performance for hydraulic fracturing and gravel packing design.
- QA/QC groups needing standardized proppant conductivity data for vendor comparisons.
Practical uses include comparative ranking of proppant types (sand, ceramics, resin‑coated), evaluating long‑term conductivity trends under incremental closure stresses, and supporting material selection in completion design.
Related standards
- ISO 13503 (other parts: Part 1, Part 2, Part 3, Part 4) - related completion fluids and proppant test methods.
- ISO 3506‑1 - referenced for material (fastener) properties.
- API RP 61 - influential reference for the development of this procedure.
Keywords: ISO 13503-5:2006, proppant conductivity, long‑term conductivity testing, hydraulic fracturing proppants, gravel packing, proppant pack testing, proppant permeability.