API 13A Barite Requirements: Tests and Limits

What does API 13A cover?

API Specification 13A covers drilling-fluid materials and their test procedures. For barite, it recognizes separate 4.2 g/mL and 4.1 g/mL product grades. This article focuses on conventional 4.2-grade barite, the grade supplied on the KANIPER API drilling-barite product page.

The official API catalogue lists the 19th edition as the current published edition at the date of this article, with later addenda and errata. A purchase order should name the required edition and amendments because specifications can change.

Short answer: A 4.2-grade lot is not accepted from specific gravity alone. Every applicable limit in the agreed specification must pass using the prescribed test method.

Principal acceptance limits for 4.2-grade barite

Property	Acceptance limit	Why buyers check it
Density	Minimum 4.20 g/mL	Confirms the required weighting-material grade.
Water-soluble alkaline-earth metals, as calcium	Maximum 250 mg/kg	Controls soluble contaminants that can affect a drilling-fluid system.
Residue greater than 75 µm	Maximum 3.0% by mass	Limits oversized particles that can create handling or equipment concerns.
Particles smaller than 6 µm, equivalent spherical diameter	Maximum 30% by mass	Limits excessive ultrafine material and supports consistent fluid behaviour.

All four results should be read together. A density of 4.20 g/mL or more does not compensate for a failed soluble-metals or particle-size result. Likewise, “200 mesh” is not a complete substitute for the two particle-size requirements. For mesh terminology, see barite 200 mesh versus 325 mesh.

How to read the test report

Request a certificate of analysis for the actual production lot or shipment. It should identify the product grade, batch or lot, test date, result, unit, limit and test method. A TDS normally describes the product range; it is not automatically proof of the result for one shipment.

Document item	Buyer question
Grade and referenced edition	Does the report clearly state 4.2 grade and the agreed API 13A edition?
Batch identification	Can the result be traced to the material being shipped?
Result and unit	Is there a numerical result, rather than only the word “pass”?
Method and laboratory	Was the specified procedure used by a competent laboratory?
Additional purchase limits	Do moisture, chemistry, packaging or other contractual requirements also pass?

Three claims that should not be confused

Meeting test limits means the reported sample satisfies the stated requirements. Supplying to API 13A requirements requires the applicable specification, sampling, testing, marking and purchasing conditions to be addressed. Using the API Monogram is different again: the manufacturer must hold the relevant API licence. Passing a laboratory table alone does not authorize the API mark.

Values such as BaSO₄ content, moisture or packaging conditions may be useful supplier or contract specifications, but they should not be presented as universal API acceptance limits unless the applicable standard says so. The difference between density grades is covered in barite 4.2 versus 4.1.

Buyer acceptance checklist

State the barite grade and applicable API 13A edition in the enquiry and purchase order.
Agree sampling, laboratory and test methods before shipment.
Verify all four principal results for the actual lot.
Check units carefully: g/mL, mg/kg, micrometres and mass percentage are not interchangeable.
Keep supplier-specific limits separate from API requirements.
Do not describe a producer or product as API Monogram licensed without checking the official API directory.
Retain the COA and traceability records for incoming inspection.

To request technical documents or discuss a trial lot, contact the KANIPER team.

Official references

American Petroleum Institute, API Specification 13A, Drilling Fluid Materials, 19th edition with applicable addenda and errata.
ISO 13500:2008, Petroleum and natural gas industries — Drilling fluid materials — Specifications and tests, including Amendment 1 for barite 4.1.
American Petroleum Institute, API Monogram and APIQR programme documents.

Need a drilling-barite specification or batch report?

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