Barite: Frequently Asked Questions
Answers to the questions drilling fluid companies, mud engineers and traders most often ask about barite grades, specifications and supply. If your question isn’t answered here, contact us.
About barite and API barite
What is barite?
Barite (also spelt baryte, or called barytes) is a natural mineral made up of barium sulphate (BaSO4). Pure barite has a specific gravity of about 4.5, which is unusually high for a non-metallic mineral. It is also soft, chemically inert and practically insoluble. Most barite is used as a weighting agent in oil and gas drilling fluids. It is also used in paints, plastics, brake linings, high-density concrete and radiation shielding.
What is API barite?
API barite is barite powder that meets the requirements of API Specification 13A, Specification for Drilling Fluids Materials, published by the American Petroleum Institute (the equivalent international standard is ISO 13500). The specification sets a minimum density, a maximum level of water-soluble alkaline earth metals (expressed as calcium) and limits on particle size, so that the barite weights the drilling fluid without upsetting its chemistry or flow properties.
What are the API 13A requirements for barite?
For standard API barite (4.2 grade) the requirements are: density 4.20 g/ml minimum; water-soluble alkaline earth metals as calcium 250 mg/kg maximum; residue greater than 75 µm 3.0% by mass maximum; and particles smaller than 6 µm (equivalent spherical diameter) 30% by mass maximum. The 4.1 grade has the same limits except that the minimum density is 4.10 g/ml. APM’s own specification adds limits on BaSO4 content, extractable carbonates, mercury, cadmium and moisture. See our API barite powder specification.
What is the difference between 4.1 and 4.2 SG barite?
The difference is the minimum density: 4.20 g/ml for API barite 4.2 and 4.10 g/ml for API barite 4.1. The 4.1 grade was added in later editions of API 13A so that good-quality ores with a slightly lower density could be used. Because 4.1 barite is less dense, more of it is needed to reach a given mud weight, and the maximum practical mud weight can be lower. Mud engineers should allow for the difference in their fluid calculations. APM supplies both grades.
Grades and forms
What is the difference between drilling grade and chemical grade barite?
Drilling grade barite is used to weight drilling fluids. It is judged mainly on density, soluble alkaline earth metals and particle size (once ground), and colour does not matter. APM’s drilling grade barite ore is available from 3.95 to 4.30 SG. Chemical grade barite has a higher purity and density: APM’s specification is 4.35 SG minimum and 94% BaSO4 minimum. It is used where high density is needed but colour is not critical, for example in brake linings. For paints, coatings and plastics, where brightness matters, we supply white barite ore and natural barium sulphate.
What is the difference between barite ore and barite powder?
Barite ore (lumps) is the crushed, mined product. APM’s drilling grade ore is supplied in lumps of 0–200 mm and usually ships in bulk vessel lots. It is bought by grinding plants and traders, who mill it to API specification near the market. API barite powder is already ground to the API 13A particle size limits and is ready to add to drilling fluid. It ships in big bags or small bags.
Why is barite used in drilling fluids?
Barite is dense and chemically inert. Adding it to a drilling fluid raises the mud weight. This increases the hydrostatic pressure in the wellbore, which helps to control formation pressure, keep the hole stable and prevent influxes of formation fluid (well control). Because barite does not react with other mud additives, the fluid’s chemistry stays predictable.
Quality and testing
How is barite tested?
API 13A sets out standard laboratory methods for barite. Density is measured with a Le Chatelier flask. Water-soluble alkaline earth metals are measured as calcium by EDTA titration of a filtered water extract. Residue above 75 µm is measured by wet sieving. The proportion of particles below 6 µm is measured by sedimentation using a hydrometer. Buyers often also specify tests for BaSO4 content, heavy metals such as mercury and cadmium, and moisture. Each shipment is supported by a certificate of analysis, independent third-party testing (for example, SGS), and a loading inspection report. Samples are available.
Ordering and supply
Where does APM’s barite come from?
APM sources API barite powder from long-term suppliers in China, Vietnam, India, Morocco and Mexico. Drilling grade barite ore comes directly from mines in China, India, Pakistan, Morocco, Turkey and Mexico. White barite ore and natural barium sulphate are sourced from China. Having several origins lets us match supply to each buyer’s specification and destination.
What is the minimum order quantity?
Order quantities range from 24 MT up to 100,000 MT. Barite ore is usually shipped in bulk lots of 30,000–65,000 MT. API barite powder can be shipped in containers, which suits smaller orders.
How is barite packed and shipped?
API barite powder is available in bulk, 1 MT, 1.25 MT and 1.5 MT big bags, 25 kg bags, 50 kg bags and printed bags. Drilling grade barite ore is usually shipped in bulk vessel lots of 30,000–65,000 MT. APM offers all the main Incoterms, including FOB, CFR and CIF, and quotes whichever suits the buyer.
How do I request a barite quote?
Use our RFQ form, email info@angpacmin.com or call +44 7822 032755. To help us quote quickly, tell us the product and grade (for example API barite 4.2 or 4.1), any specification requirements, the quantity, your packing preference, the delivery port or destination, and your payment terms.
Which regions does APM supply?
APM supplies barite to drilling fluid companies, mud engineers and traders in the Middle East, Africa, Europe, North America and South America, with clients in 18 countries. Key destination ports include Dammam, Abu Dhabi, Corpus Christi, New Orleans and Antwerp, and Argentina is a particular focus. See our barite supplier regions page for more detail.