Content area
Full text
As unconventional shale oil and gas exploration and development continues at pace in North America and further afield, Andrew Scogings, Industrial Minerals Consultant, provides an executive summary of IM's upcoming research report on drilling-grade barite.
Barite (barytes) is naturally-occurring barium sulphate (BaSO[subscript]4 ) and is the predominant barium mineral used for industrial purposes. The mineral occurs in veins, stratiform beds and lenses in addition to residual deposits. The largest deposits currently mined are stratiform beds in China, India and the US. Barite is utilised primarily for its high specific gravity (SG 4.5) in addition to its chemical and physical inertness, relative softness and very low solubility.
Mineral weighting alternatives to barite include celestite, calcium carbonate, ilmenite and synthetic hematite. Apart from calcium carbonate, none of these mineral substitutes has had a major impact on the barite drilling mud industry. Cesium formate brines (SG 2.2) have been developed for challenging high pressure, high temperature (HPHT) drilling operations and are produced from pollucite at the TANCO lithium mine in Manitoba, Canada.
Table 1: American Petroleum Institute barite specifications
API 13A - Barite physical and chemical requirements
Requirement Standard
Density (Clause 7) 4.20 g/ml, minimum
Density (Clause 20) 4.10 g/ml, minimum
Water-soluble alkaline earth metals, as calcium 250 mg/kg, maximum
Residue greater than 75 m Maximum mass fraction 3.0%
Particles less than 6 m in equivalent spherical diameter Maximum mass fraction 30%
Source: API Specification 13A, August 2014
Table 2: Drilling grade barite prices, December 2014
Low $ High $
Barite, Drilling grade, ground SG 4.22, bagged, FOB Morocco, $/tonne 110 170
Barite, Drilling grade unground lump, OCMA/API, Bulk, SG 4.20, FOB Chennai, $/tonne 138 145
Barite, Drilling grade, API unground lump, SG 4.20, FOB China, $/tonne 112 128
Barite, Drilling grade unground lump, OCMA/API bulk, SG 4.10 FOB Chennai, $/tonne 110 125
Barite, Drilling grade, API unground lump, SG 4.10, FOB China, $/tonne 109 113
Barite, unground lump, OCMA/API bulk, SG 4.20, FOB Morocco, $/tonne 115 127
Barite, API, lump, CIF Gulf Coast, Chinese, $/tonne 145 160
Source: IM
Reserves, production and consumption
No reliable information is available with regard to the total world reserves of barite, however the US Geological Survey (USGS) estimates 350m tonnes of reserves of which China, India and Kazakhstan are claimed to...