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Requirements for drilling grade barite: now and
tomorrowThe case for adopting an alternative
specification for drilling grade barite in normal applications
Drilling fluids
- Clean cuttings from well bottom- Flush cuttings to the surface- Cool and lubricate the drill bit- Deposit a “filter cake” layer on well bore wall to
prevent loss of the circulating fluid itself- Prevent formation fluids from entering the borehole
and mixing with circulating fluids- Support the “walls” of the well (wellbore) without
damaging the formation- Control pressures under the surface
Drilling fluids types
- Barite is used in all types of fluid systems• Water-based muds (WBM’s)• Oil-based muds (OBM’s)• Synthetic-based muds (SBM’s)
Barite’s purpose in drilling fluid
- Provide density to drilling muds• major factor in controlling pressures downhole• up to 22 lbs/gallon of mud
- Remain chemically neutral (inert)- Avoid abrasive damage to drilling string, bits, and
circulating system- Do all the above at a low enough cost to be
disposable
Specifications
- API, Spec 13A, Section 2, and Appendix B• density = 4.20 g/cm, minimum• water-soluble alkaline earth metals as calcium = 250
mg/kg, maximum• residue greater than 75 micrometers = 3.0%, maximum
(wt.)• particles less than 6 micrometers = 30.0%, maximum
(wt.)- Typical Non-API customer specifications
• caustic soluble carbonates = 1,500 Mg/Kg, maximum- Typical environmental regulatory specifications
• Mercury = 1 ppm, maximum• Cadmium = 3 ppm, maximum• Others
Top producers
• China = 2.70 MMMT (46%) Mostly lumps to USGOM
• India = .78 MMT (13%) Lumps/powder to GOM, LA, ME
• Morocco = .45 MMMT (7%) Lumps to NS, US, powder to WA
• USA = .42 MMMT (7%) Powder to non-GOM US/Canada
• Iran = .22 MMMT (4%) Internal and regional
• Turkey = .16 MMMT (3%) Mostly powder to Med., Caspian
• Top 6 = 4.73 MMMT (80%)
• World = 5.8 MMMT (100%)
Key Issues – Global Availability – from Nevada
• USA- Nevada is ONLY US source- Nevada ore is environmentally very “clean” due to a
unique geology- Nevada, US produces <10% of the world’s production- Nevada able to supply less than 20% of USA/NA
demand of 2.5MM tons per typical year- USA/NA demand not expected to decline soon- No new Nevada or other US sources of mine-able
4.20 density- Reserves are depleting rapidly, especially given
current demand in Rockies/Mid-Cont/Western Canada/Alaska
• Given these factors- Balance must come from China/India/Others
Key Issues – Global Availability – from Nevada
• Nevada reserves depleting
BARITE ORE RESERES - NEVADA
0
2,000,000
4,000,000
6,000,000
8,000,000
10,000,000
12,000,000
14,000,000
2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020
YEARS
TONS
$100,000,000 INVESTMENT
4.20 SPECIFIC GRAVITY
$7,500,000 INVESTMENT
4.10 SPECIFIC GRAVITY
CURRENT
4.20
11 YEARS RESERVESCAP COST = $1.15/ton
20 YEARS RESERVESCAP COST = $8.06/TON
Key Issues – Global Availability – from China
• China - Approximately half of the world’s drilling grade supply- Not all environmentally acceptable in all areas of demand- Currently satisfying 80% of US demand and all GOM
• Reserves - Guangxi Province of China reserves are on a similar
pattern as Nevada even though the scale of annual production is more like 4x or 5x Nevada
• Long lead supply chain vulnerabilities- Each cargo planning cycle is ~4 months- Industry brings +/- 30 cargoes across each year
• Political vulnerabilities - Possible future actions of both governments
• Growing indigenous demand
• Environmental vulnerabilities- Assurance of offshore specification requires high degree of
vigilance
Key Issues – Global Availability – from India/Others
• India is grossly/notoriously undependable in recent years- State government bureaucracy controls the ONLY mine- Flooding problems- Strikes- 500,000 MT exports in the best of years- Growing indigenous demand
• India – environmentally clean but shrinking as a viable producer- Currently seeking Chinese to supplement indigenous!
• Even small players are problematic- Spain – heavy metals and limited production- Morocco – limited production- Turkey – distance to market and logistics constraints- Mexico – virtually tapped out and what’s there is domestic
• Mexico is importing Chinese, Indian, Other- Peru – heavy metals and logistics constraints
• No new deposits in the world since the late ’70’s early ’80’s boom period
A solution if acted upon soon
• Offer an alternate specification 4.10 density in addition to API 13A Section 7- Specifications to coexist- Grind specifications, soluble alkaline earths
expressed as calcium, packaging requirements will remain unchanged
• Use alternative specification wherever appropriate
• Allow customers to decide
• Foster a responsible use of available world reserves
Technology
Solids volume increase in weighting up a 10.0 lb/gal mud by 1.0 lb/gal is only 0.14%, specifically 3.98% for 4.20 density barite and 4.12% for 4.10.
Additional Solids required to Weight-up from 10.0 ppg Fluid Using 4.10 and 4.00 density instead of 4.20
0.00%
0.50%
1.00%
1.50%
2.00%
2.50%
11 12 13 14 15 16 17 18
Final Fluid Weight in #/gallon
Pe
rce
nt
Ad
ded
So
lids
fro
m B
ari
te
Additonal Solids Percent using 4.10 density Barite
Additonal Solids Percent using 4.00 density Barite
Technology
Weight-up from 10.0 ppg using4.20, 4.10, and 4.00 density Barite
0.00%
5.00%
10.00%
15.00%
20.00%
25.00%
30.00%
35.00%
40.00%
11 12 13 14 15 16 17 18
Final Fluid Weight in #/gallon
Per
cen
t S
olid
s fr
om
Bar
ite
Percent Solids Added 4.20 density Barite
Percent Solids Added 4.10 density Barite
Percent Solids Added 4.00 density Barite
Even on a highly weighted mud of 18 lb/gal, the percent solids introduced by 4.20 density (current API) barite are 31.88% versus 32.98% using 4.10 density barite. The net effect is a 1.1% addition of solids. At the extreme only ~1% more barite needs to be added
Technology
• Performance of the system Plastic Viscosity Comparison
Dispersed Lignosulfonate MudsHeat aged 16 hrs @ 150 deg. F
10
15
20
25
30
35
40
45
50
55
60
12.0 ppg 17.0 ppg
Density, lb/gal
PV
, cen
tip
ois
e
4.2 sg
4.1 sg
Yield Point ComparisonDispesed Lignosulfonate MudsHeat aged 16 hrs @150 deg. F
4
6
8
10
12
14
16
18
20
12.0 ppg 17.0 ppg
Density, lbm/gal
Yie
ld P
oin
t, lb
/100
sq
. ft
sq.
4.2 sg
4.1 sg
Introduction challenges/benefits
• Will require suppliers to offer both grades perhaps indefinitely- Some logistical challenges- Some additional QA challenges
• The new alternate must never be below the 4.10 minimum density- Transitional mill production <4.20 will be included
even though much higher than 4.10 minimum
American Petroleum Institute (API)
• Considering- Adding an API specification for the alternative density
barite- Customer assurance factor- One alternative instead of many- Using the same testing and auditing protocols as Section 7- Maintaining same grind specifications, soluble alkaline
earths expressed as calcium, and packaging requirements
• Next actions - Opening a dialog on the subject- Looking at technical details- Raised in January 2006 – Savannah, Georgia- To be reviewed starting in June/July 2006
• The result- Supporting responsible use of available world reserves for
the future good of the energy industry
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