Mmmmmmuuuuuudddddd compositionnnnnnn.ppt

Mud

1. Mud CompositionMud Composition

2. Composition:Composition:
PhasesPhases

Phases of a Drilling Fluid

Water (continuous) phase

Reactive commercial clay solids

Reactive formation (drilled) solids

Inert formation (drilled) solids

Inert commercial solids

Soluble chemicals

3. Composition:Composition:
Water phaseWater phase

Definition: The continuous (liquid) phase of
the drilling fluid (mud)

Can be fresh water, brackish water, sea water,
saturated salt water, or another type of brine
fluid

Can be hard water containing a high
concentration of calcium or magnesium

4. Composition:Composition:
Fresh waterFresh water

Usually available only on land locations

Advantages:

Commercial clays hydrate more

Most chemicals are more soluble

Disadvantages:

Formation clays hydrate more, which
can result in hole problems and damage
to the producing zone

5. Composition:Composition:
Brackish waterBrackish water

Usually in a marine environment

Slightly salty

Higher calcium and magnesium than
fresh water

6. Composition:Composition:
Sea waterSea water

Chlorides and hardness varies

Chlorides in Gulf of Mexico 15,000 -
30,000 mg/l

Calcium in Gulf of Mexico 400 ± mg/l

Magnesium in Gulf of Mexico 1200±
mg/l

Hardness in North Sea much higher

7. Composition:Composition:
Saturated salt waterSaturated salt water

Used primarily to drill through large salt
formations

Salt must be added to achieve saturation

Prevents hole enlargement due to
leaching or dissolving salt from the
formation

Leaching could result in hole problems
and expensive mud and cement costs

8. Composition:Composition:
Brine waterBrine water

Usually used for clay (shale) inhibition

Potassium chloride (KCl)
Calcium Chloride CaCl
2

Formates (Na
+
,K
+
)

Bromides

9. Composition:Composition:
Reactive solidsReactive solids

S.G. = 2.6, Density = 21.67 ppg

Commercial clays

Sodium Montmorillonite or Bentonite

M-I GEL

Attapulgite

SALT GEL

10. Composition:Composition:
Reactive solidsReactive solids

Formation clays (drilled solids)

S.G. = 2.6, Density = 21.67 ppg

Montmorillonite (swelling clay)

Illite (non-swelling clay)

Kaolinite (non-swelling clay)

Chlorite (non-swelling clay)

Gumbo Shale (combination of above
clays)

11. Composition:Composition:
Inert solidsInert solids

Commercial

Barite (barium sulfate)

S.G. = 4.2, Density = 35 ppg

(M-I BAR)

Used to increase mud density up to
maximum of 22 ppg±

12. Composition:Composition:
Inert solidsInert solids

Hematite (iron oxide)

S.G. = 5.0, Density = 41.67 ppg

Fer-Ox

Used to increase mud density up to
maximum of 25 ppg ±

13. Composition:Composition:
Inert solidsInert solids

Calcium Carbonate

S.G. = 2.8, Density = 23.34 ppg

Acid soluble

Lo-Wate

Used to increase fluid density up to
maximum of 14.0 ppg ±

Used as bridging agent in drill-in, oil
and synthetic fluids

14. Composition:Composition:
Inert solidsInert solids

Lost Circulation Material

Material used to bridge off (seal)
formations where whole mud is being
lost to the formation

Nut shells (mostly pecan & walnut)

Mica

Fiber (wood, paper, plastic, etc.)

15. Composition:Composition:
Inert solidsInert solids

Formation solids

S.G. = 2.6 ±, Density = 21.67 ppg ±

Sand

Limestone

Dolomite

16. Composition:Composition:
Soluble chemicalsSoluble chemicals

Caustic Soda (NaOH) pH 13.3

Caustic Potash (KOH) pH 13.3
Lime [Ca(OH)
2] pH 12.4
Soda Ash (Na
2
CO
3
) pH 11 - 11.5
Sodium Bicarb (NaHCO
3)pH 8.4

Zinc Oxide (ZnO)

17. Composition:Composition:
Soluble chemicalsSoluble chemicals

Lignosulfonate (organic acid)

Spersene (chrome lignosulfonate)

Spersene CF (chrome-free
lignosulfonate)

Chemical de-flocculant (mud thinner)
adds anionic (negative) charges to the
mud.

18. Composition:Composition:
Soluble chemicalsSoluble chemicals

Lignite (organic acid)

Tannathin (lignite)

XP-20 (chrome lignite)

Chemical de-flocculant (mud thinner)
adds anionic (negative) charges to the
mud.

Neutralizes positive sites on the clays
causing them to repel each other.