API Class G HSR Well Cement Supplier & Exporter

Class G HSR API Spec 10A-2019 · High Sulfate Resistant

API Class G high sulfate-resistant well cement tested to API Spec 10A-2019 — thickening time 105 minutes, 8-hour compressive strength 570 psi at 38 °C and 1945 psi at 60 °C, free fluid 3.03% and C₃A held to 1.90%. The basic well cement for primary and remedial cementing across a wide depth and temperature range using accelerators or retarders.

Request a Class G Quote Packaging & Incoterms

API Class G HSR oil well cement for primary and remedial well cementing — B2B bulk export supplier Raivaco

C₃A 1.90%

105 min

Thickening time (spec 90–120)

1945 psi

8 h CS at 60 °C (min 1500)

1.90%

C₃A content (max 3)

Per batch

Quality control test report

Physical Properties

Standard

API Spec 10A-2019

Class

G — HSR

Blaine Fineness

3260 cm²/g

Slurry Density

119 pcf

Free Fluid

3.03%

Max Consistency

21 Bc

Synonyms: Class G Cement, Oil Well Cement, OWC, HSR Well Cement, API 10A Cement · Basic well cement usable from surface to intermediate depths with additives.

Grades & Chemical Analysis

Full physical and chemical test results for API Class G HSR well cement, each shown against the API Spec 10A-2019 criterion it is measured against.

Physical Tests — Result against API criterion

Class G — Slurry Performance

API 10A

Thickening time (100 Bc): 105 min (spec 90–120)
8 h CS @ 60 °C, atmos.: 1945 psi (min 1500)
8 h CS @ 38 °C, atmos.: 570 psi (min 300)
Free fluid: 3.03% (max 5.9)
Max consistency, 15–30 min: 21 Bc (max 30)
Blaine fineness: 3260 cm²/g
Slurry density: 119 pcf
Autoclave expansion: 0.07% (max 0.8)

Tested to API Spec 10A-2019 under an accredited quality control laboratory. Values are typical batch results; a batch-specific test report is issued per shipment.

Bespoke Supply

Need Class H or a moderate sulfate-resistant grade?

API Class H for deeper wells and Class G in the MSR variant can be sourced. Send us your well profile, bottom-hole circulating temperature and target thickening time and we will confirm the right class and lead time.

Request a Custom Grade

Applications

Class G is the workhorse of well cementing — a basic cement designed to accept whatever additive package the well actually needs.

Primary Casing Cementing

Surface, intermediate and production casing strings.

Zonal Isolation

Sealing productive zones and preventing crossflow.

Squeeze Cementing

Remedial repair of casing leaks and channels.

Liner Cementing

Cementing liners in deviated and horizontal sections.

Plug & Abandonment

Permanent barriers on well decommissioning.

Kick-off & Cement Plugs

Sidetrack kick-off plugs and lost circulation control.

Water Well Cementing

Annular seals in water and geothermal wells.

Sulfate-Rich Formations

HSR chemistry for aggressive downhole brines.

Slurry Design Base

Base cement for extended, densified and foamed systems.

Packaging, Logistics & Trading Terms

How we package, certify and ship API Class G cement. Terms can be adapted by agreement — tell us what your operation needs.

Minimum Order Quantity: 1 × 20 ft container (approx. 25 MT) bagged. 500 MT minimum for bulk vessel. Trial quantities available for slurry-design qualification.
Packaging: Bulk pneumatic tanker, 1.5 MT jumbo bags, or 50 kg moisture-barrier bags. Bulk delivery to wellsite silos can be arranged on regional contracts.
Incoterms & Loading Ports: EXW, FOB, CFR and CIF (Incoterms® 2020). Standard loading at Bandar Abbas and Bandar Imam Khomeini; other ports by arrangement.
Quality Certification: Batch-specific API Spec 10A-2019 quality control test report with every shipment, covering thickening time, free fluid, compressive strength at 38 and 60 °C, and the full chemical analysis.
Lead Time: 7–14 days for standard grades after order confirmation; 15–25 days for custom-milled or specially packed material.
Storage & Handling: Store in sealed, moisture-tight conditions. Well cement performance is far more sensitive to pre-hydration than construction cement — even slight moisture pickup shifts thickening time and can compromise a cement job. Retest before use if storage exceeds 6 months.

Certificate of Analysis

A batch-specific CoA is issued with every shipment. Third-party inspection by SGS, Bureau Veritas or an inspector of your choice can be arranged at the buyer’s cost.

Ready to quote

Send us your grade, tonnage, destination port and packaging and we will return a firm FOB/CFR/CIF price with lead time.

Request a Class G Quote

API Class G Well Cement — Frequently Asked Questions

What does HSR mean and why does Class G need it?

High Sulfate Resistant. Downhole formation waters frequently carry high sulfate concentrations, and sulfate attacks the C₃A phase in set cement, causing expansive cracking that destroys zonal isolation. The API HSR grade caps C₃A at 3% and C₄AF + 2C₃A at 24%; our material runs 1.90% and 18.10% respectively.

What is thickening time and why is 90–120 minutes the target?

Thickening time is how long the slurry stays pumpable, measured as the time to reach 100 Bearden units of consistency. It has to be long enough to mix and place the full slurry volume with a safety margin, and short enough that you are not waiting on cement. Ours runs 105 minutes, mid-window. Retarders extend it for deep or hot wells; accelerators shorten it for shallow ones.

Why is free fluid limited?

Free fluid is water that separates out of the slurry at rest. In a deviated or horizontal well it collects on the high side of the annulus and creates a continuous channel that defeats zonal isolation entirely. API caps it at 5.9% for Class G; ours measures 3.03%.

What is the difference between Class G and Class H?

Both are basic well cements designed to work with additives, but Class H is ground coarser and generally used at higher slurry densities and greater depths. Class G is the more widely used of the two and covers most primary cementing applications from surface to intermediate depth with the appropriate additive package.

How sensitive is Class G to storage conditions?

Considerably more than construction cement. Any moisture pickup pre-hydrates the cement and shifts thickening time, which is the one property a cement job cannot tolerate being wrong. Store in sealed, moisture-tight packaging, and retest thickening time before use if the material has been stored longer than 6 months.

Is the test report independently verified?

Testing is performed to API Spec 10A-2019 by an accredited quality control laboratory, and a batch-specific report accompanies every shipment. Third-party inspection and independent slurry testing by an inspector of your choice can be arranged at the buyer’s cost.

Related Products

Portland Cement Type II Moderate sulfate resistance for construction in aggressive ground. Barite API 13A weighting agent for the drilling fluid ahead of the cement job. All cement products & trade terms Compare Portland, white and oil-well grades, MOQ, Incoterms and packaging.