Primary tabs
Hematite
HEMATITE is a high density weighting material. The hematite ore used as a weighting agent in drilling fluids has a mica like crystal structure
ground to a particle size suitable for use in drilling fluids.
Hematite is applicable in all types of drilling fluids, including freshwater, seawater and oil-base muds. It can be used to increase the density of all drilling and completion fluids to 25 lb/gal (3.0 SG).Hematite is most frequently used in high-density, oil-base muds. Fluids weighted with Hematite contain fewer solids by volume than those weighted with barite, making higher mud weights possible. It is especially useful in high-density kill fluids.
The quantity of Hematite required can be calculated using the following formula:
1,750 (w2- w1)
Hematite , lb/bbl= ----------------------
41.66 - w2
Where:
w1= Initial mud weight in lb/gal
w2= Desired mud weight in lb/ga
5,000 (w2- w1)
Hematite, kg/m3 = -------------------------
5.0 - w2
Where:
w1= Initial mud weight in specific gravity
w2= Desired mud weight in specific gravity
Advantage :
regarded as a secondary sulfide scavengerWhen Hematite is used in H2S areas, a high pH should be maintained and an appropriate primary scavenger, should be used.
- Muds contain fewer solids than similar-density barite muds due to the 20% higher specific gravity
- Muds have improved rheological values; generally plastic viscosities are 2 to 30% less than barite muds.
- Use of muds usually results in higher rates of penetration.
- Higher bulk density than barite, consequently more weight is held in the same volume bulk tanks and a smaller volume must be transported to the wellsite.
- Less Hematitethan barite isrequired to achieve the same mud weight, reducing mud costs.
- Has a narrower particle size distri-bution with a larger average particle size as compared to barite.
- A harder mineral than barite, thus more resistant to particle-size degradation.
- Approximately 97% acid-soluble in 15% hydrochloric acid (HCl).Will partially scavenge hydrogensulfide at neutral and low pH levels and
- May be environmentally preferred to barite in certain locations
Physical appearance : Dry – red to brown powder
Particle hardness : 5 – 6 MOHS scale (1-10)
Bulk density :143 lb/ft3 (2,291 kg/m3)
Specific gravity : 5.0
Particle size :<1.5% wt >200 mesh (75 micron)
:<15% wt ~325 mesh (>45 micron)
:<15% wt <6 micron
Soluble hardness :<100 mg/kg