Upload
others
View
2
Download
0
Embed Size (px)
Citation preview
Drilling and Design C id iConsiderations
for
Methane DrainageMethane Drainage
Mongolia Coal Mine Methane gProject Development
Workshop
Ulaanbaatar HotelUlaanbaatar, Mongolia
August 30-31, 2010
Presentation OutlineIntroduction
Observations
Methane Drainage Design
Fundamentals of Directional Drilling
- Equipment
- Techniques
Gas Collection
Methane Drainage Techniques
Summary
REI DRILLING, INC.• Operate 8 long hole directional drills and
2 core drills on a contract basis across North America
• Became affiliated with Valley Longwall International in 2008
• Jointly operate >25 long hole drills ld id t t b iworldwide on a contract basis
• Turnkey package of directional drilling units for sale and training for coal miningMethane drainage consulting and• Methane drainage consulting and directional drilling training
• Design and implement methane recovery and sale projectsand sale projects
• Managed and participated in numerous international directional drilling projects
• Expanded uses for directional drilling, p g,e.g. exploration and dewatering
• >25 years experience
International CMM Industryu Coal is the most abundant fossil fuel IEO predicts continuedu Coal is the most abundant fossil fuel. IEO predicts continued
reliance and consumption of coal increasing by 50% by 2030.u Mining technology continues to evolve resulting in more rapid
excavation and production techniques. u We continue to mine deeper, gassier and more challenging coal
reserves. This has resulted in a need to improve methane drainage techniques.U f f d ill d th d i ll h b ff t du Use of surface drilled methane drainage wells has been affected due to surface ownership, approvals, topography, culture, lack of equipment, etc.
u Many coal reserves develop multiple coal seams and require flexibleu Many coal reserves develop multiple coal seams and require flexible methane drainage approach.
u Gas collection systems typically use steel pipeline and demonstrate significant erosion of gas quality from wellhead to surface.significant erosion of gas quality from wellhead to surface.
u There is a recognized need to mitigate methane emissions and demonstrate environmental awareness.
u The international CMM industry shows tremendous growth and y gspread of upstream and downstream technologies.
• Source of gas emissions– Adjacent gas bearing strata, geologic
features or working seam• Geologic characterization• Geologic characterization
– Coal thickness, rank, stress, friability, other mechanical properties
• Reservoir characterizationG– Gas content, permeability, porosity, reservoir pressure, and desorption time constant
• Mining technique and schedule– Gate road development, start of LW,
available drainage times, multiple seams• Drainage approach
– Source, feature, or shield focused, ,• Logistics
– Surface and underground access • Gas Utilization
– Alternatives, gas quality– Market
OPTIMIZE VENTILATION AND METHANE DRAINAGEDRAINAGE
Geologic and Reservoir CharacteristicsGeologic and Reservoir Characteristics
• Gas content of the coal d h l iseam and shale is
commonly determined through the “directthrough the direct method.”
• Core or cuttings are placed in canisters.
• Simulate reservoir conditionsconditions.
• Monitor gas production from core/cuttingsfrom core/cuttings.
Geologic and Reservoir Characteristics• Matrix permeability is the characteristic
that affects the ability of gas (water) to flow through a materialflow through a material.
• Gas flow is also affected by cleat (faceGas flow is also affected by cleat (face and butt) presence, spacing, and jointing.
Borehole Planning and DesignComputer Simulation:Reduction in Residual Gas Content as a Function of Drainage Time and Spacing
of Cross-Panel Boreholes
80%
60%
70%
ent (
%)
40%
50%
idua
l Gas
Con
t
20%
30%
duct
ion
in R
esi
300 ft Spacing
150 ft Spacing
100 ft Spacing
0%
10%
0 1 2 3 4 5 6 7 8 9 10 11 12
Red
0 1 2 3 4 5 6 7 8 9 10 11 12
Months
Why Consider Long Hole Directional Drilling?• Allows longer length and more• Allows longer length and more
accurate placement of boreholes for improved methane drainage efficiency and longer drainageefficiency and longer drainage times
• Allows implementation of i ti b d iinnovative gob gas drainage techniques
• Ability to steer borehole to stay in-seam or hit specific targets
• Promotes a more focused, simplified gas collection systemsimplified gas collection system
• Less labor intensive • Provides additional geologic
i f ti ( h linformation (such as coal thickness, faults, and other anomalies, etc. prior to mining
Long Hole Directional Drills
VLD Series 1000 Track Mounted Directional Drill System
Roof StingerRoof Stinger
Rotation Unit
DGS Uphole Unit Front Chuck
Feed Frame
Track System Stab Jack
VLD SERIES 1000 MODULAR DIRECTIONAL DRILL RIGDIRECTIONAL DRILL RIG
Modular system follows the same design principles as the track mounted system but is broken down into three main componentsmounted system but is broken down into three main components -
power pack, feed frame, and operator’s console - to be used in areas where access is difficult, or there is limited access from the surface.
Operator’s ConsolePower PackFeed Frame
Water Power
100
120
60
80
GP
M
0
20
40
0CDP 70 CDP 100
Down Hole Motors
278/56
312/78
0 50 100 150 200 250 300 350 400Torque
Directional Drilling TechnologyDirectional Drilling Technology• REI uses down hole motor directional drilling technology to
accurately steer long holes in coal seams. A down hole motor, operating on the Moyno pump principle converts hydraulicoperating on the Moyno pump principle, converts hydraulic (water) energy to mechanical torque (bit) without rotation of the drill rods.
• Drillers control direction by orienting a bent housing behind the bit through rotation of the rods The axial force exerted by thebit through rotation of the rods. The axial force exerted by the drill on the rods is distributed to the bit by the bent housing according to its orientation.
Drill BitsPolycrystalline Diamond Cutter (PDC) Impregnated Diamond
Borehole Surveying InstrumentsR l Ti S i DMM MECCA I t tReal Time Surveying – DMM MECCA Instrument
Directional Drilling TechnologyDirectional Drilling Technology• Drillers maintain boreholes in-seam by monitoring down hole
motor pressure, axial thrust, cuttings, and survey information. • Using this system drillers can develop tangential boreholes• Using this system, drillers can develop tangential boreholes
(side-tracks) to help maintain the borehole in-seam, correct trajectory, or develop multiple boreholes from one main branch.
NORTH AMERICAN RECORD• October 6, 2006 • 1623 meters
Drilling ConfigurationDrilling ConfigurationRoof
Reinforced Hose to Pipeline or Diffusion Line
Provisions forGas Measurements
Grout (Cement)Blow Out Preventer
Drill Rod
( )
PVC St l C i
Stuffing Box
Valve
Drill RigOverflow
PVC or Steel Casing
As Necessary
Cuttings / Drilling Water
Floor
Valve and Blow Out ControlValve and Blow Out Control
Gas Handling and CollectionDrilling and Post Drilling
Coal RibLinedwithBothEndsof DilutionZoneHorizontal Borehole
DilutionZone
Canvas Door
Caution
Coal Rib Lined with Canvas or Cement Block
Both Ends of Dilution ZoneCaution Signs with Fencing
Examination PointCH4<1%at Exit
10 ft
X
X
20 to 300 ft
Gas Flow Measurement Provisions
erm
issi
ble
Dril
l Rig
Line CanvasithP t
25 to 50 ft
Canvas Door
Return AirC
autio
n
CH4 <1% at Exit Caution
X
Return Air
Pe
ll
with Posts(as necessary)
Proposed Dilution Zone
Dilution Zone
Per
mis
sibl
e D
rilP
ower
Uni
t
Return Air
Caution Sign
Caution
Dilution Zone is Rock Dustedand kept free of Ignition Sources
Gas CollectionWell head design:
4 inch Casing4 inchBall Valve
4 inch Spring ReturnPneumatic Full Port
Ball Valve
4 inchCheck Valve
4 inch Flex Suction / Discharge Tube
Gauge
4 inchBall Valve
GaugePSI / Inches HG
90 DegElbow
P Gauge
Veribar
4 inch Flex Suction / Discharge Tube
36 inches Schedule 40 (X3)
4 inch TEE
King NippleKing Nipple4 inch
Ball Valve King NippleConnect to Manifold
1/2 inch Pipeline Integrity Line
1/2 inch Pipeline Integrity Line
Sample Port
1/2 inch Pipeline Integrity Line
1/4 inch1/4 inch
8 inch Blind Flange Clean Out
Gas / Water Separator Tank3/16 inch Gage Steel
14 inches X 36 inches
1 inch
4 inch
1 inch Y Strainer
5/8 inch X 3 1/4 inch Bolts / Nuts
King NippleKing Nipple
1 inch Hose (X3)
Pneumatic Valve,Spring OpenPneumatic Valve,
Spring Closed
2 inch1 inch
1 inch Y StrainerSpring Closed
1/2 inch
Float Valve with Sending Unit
Check Valve
Pneumatic Valve,Spring Closed
Water Collection Tank3/16 inch Gage Steel
14 inches X 30 inches
1 inch
1 inch
1/4 inch
Gas Collection
Methane Drainage Techniques• Pre-Mining • Gob Degasification
Longwall Gob Fracture Zone
Coalbed
Coalbed
Coalbed
120 to140 m
Coalbed
Coalbed
Coalbed
SHIELD
50 m10 m 120 to 200 m
20 to 40 m
e / T
an
Elev
atio
n (F
t Bel
ow C
olla
r)
500400200 300100
0
0 600 700 130012001000 1100900800 1400 1500 1600 1700 19001800 2000 2100 2200 2300 2400 2500 2600 2700
-25
-50
531
Ft "G
ood
Gas"
787
Ft "
Goo
d G
as"
925
Ft "
Lots
of G
as"
472
Ft "G
asy"
394
Ft "G
asy"
236
Ft "
Gas
y"
177
Ft "
Gas
y"
138
Ft "
Little
Gas
y"
"Whi
te S
tuff"
872
Ft "
Whi
te St
uff"
1050
Ft "
Rock
"10
52 F
t "Ro
ck"
1086
Ft "
Whi
te S
tuff"
1190
Ft O
ut o
f Roo
f & B
ack
in S
eam
1260
Ft "
Good
Gas"
1378
Ft "
Lots
of G
as"
1555
Ft "
Goo
d Ga
s!!"
2280
Ft F
loor
(Red
dish
)
2346
Ft F
loor
(Red
dish
)
2126
Ft
Roc
k (Ta
n)
2110
Ft R
ock
(Tan
)
2411
Ft R
ock
2461
Ft L
osin
g C
ircul
ation
., Ro
ck
2224
Ft "
Goo
d G
as"
2569
Ft
Rock
Gra
y / R
eddi
sh /
Cho
cola
te / R
ed / T
an /
Whit
eV
ery
Stick
y
Cho
cola
te,
Har
d /
Lt B
rown /
Gray
ishR
ods
Stuc
k
1811
Ft W
arm
Wat
er (5
Gal
/ Min
)
2467
Ft
Hit F
loor
, Red
2493
Ft
Rock
, Flo
or (R
ed)
2638
Ft
Rock
HDH-13 Profile
Vertical Exageration: 4
Ultra Long BoreholesgTo Drain Gas Significantly in Advance of Mining:
Mining
B o re h o le N o . 5
gD
T D = 5 0 4 0 ft
5000
engt
h (f
t)
3000
4000
Bor
ehol
e Le
0 50 100 150 200 250 300Cumulative Recovery (MMCF)
Methane DrainageMethane Drainage• Warrior Basin - Alabama
Methane Drainage Mexico – Case Study
PrePre--Mining Mining -- Long, InLong, In--Seam Directionally Drilled Boreholes:Seam Directionally Drilled Boreholes:
Effect on Gate Road DevelopmentMIMOSA #1 Mine
Methane Emissions, Airflow Requirements, and Advance Rate Before and After Degasification for 2 West Developments, Mine I
8590
Advance Rate (10's of Meters Per Month)
Methane Emissions, Airflow Requirements, and Advance Rate Before and After Degasification for 2 West Developments, Mine I
8590
Advance Rate (10's of Meters Per Month)
70
80 80
70
80
Rat
e
Advance Rate (10 s of Meters Per Month)
Methane Emissions (1000's of Cubic Meters Per Day)
Airflow Rate (Cubic Meters Per Second)
500 m Borehole on Production
70
80 80
70
80
Rat
e
Advance Rate (10 s of Meters Per Month)
Methane Emissions (1000's of Cubic Meters Per Day)
Airflow Rate (Cubic Meters Per Second)
500 m Borehole on Production
45 45 45 45
55
50
60
low
/Adv
ance
45 45 45 45
55
50
60
low
/Adv
ance
20
30
40
Emis
son/
Airf
l
20
30
40
Emis
son/
Airf
l
0
10
0
October November December January February March April May June0
10
0
October November December January February March April May JuneOctober November December January February March April May June
Months in 1994October November December January February March April May June
Months in 1994
Gob Gas Drainage Techniquesg q
Design of Vertical CBM and CMM Wells
Methane DrainageGob Gas – Vertical Gob Wells
High Capacity Horizontal Gob Boreholes
400450
FD)
50100150200250300350
Gob
Gas
Flo
w (M
CF
050G
Cambria 33 Tiefa Saarland WillowCreek
Ukraine - Methane Drainage Approach Degassing Boreholes Drilling Diagram
Degassing BoreholesReturn Entry
Drill Rig
9th South Panel
Conveyor Entry
Legend
Intake AirReturn Air
Ventilation Door
Crossing
Hau
lage
Way
Water Sump
Sou
ther
n Sl
ope,
2nd
Sta
ge
Man
way
219
0
? - ?
453 0453 0
314
031
40
314
031
40
45 3045 30 45 3045 30
314
031
40
Upper Coal SeamDegassing Boreholes
9th South Longwall
Upper Coal SeamHaulage Way
Drill Rig
Manway
Southern Slope2nd Stage
Horizontal Gob Borehole Design Considerations • Near edges of the longwall panel where strata will be in tension.• Parallel and along ventilation return (tailgate).• On high elevation side of the gob.
( )• Above rubble zone (> 5 times mining height) to remain intact during undermining.
• Typical placement is 20 to 30 m above top of coal.
D e g a s s i n g B o r e h o l e s D r i l l i n g D i a g r a m
D e g a s s i n g B o r e h o l e sR e t u r n E n t r y
D r i l l R i g
9 t h S o u t h P a n e l
L e g e n d
I n t a k e A i rR e t u r n A i r
Hau
lage
Way
W a t e r S u m p
outh
ern
Slo
pe, 2
nd S
tage
Man
way
2190
? - ?
4 5 3 04 5 3 0
31
403
140
31
403
140
4 5 3 04 5 3 0 4 5 3 04 5 3 0
31
403
140
C o n v e y o r E n t r y
V e n t i l a t i o n D o o r
C r o s s i n g
H
U p p e r C o a l S e a mD e g a s s i n g B o r e h o l e s
U p p e r C o a l S e a mH a u l a g e W a y
D r i l l R i g
M a n w a y
S o u t h e r n S l o p e2 n d S t a g e
So
9 t h S o u t h L o n g w a l l
Krasnolimanskaya Mine
Case StudyR d ti f th Li h MiRecommendations for the Liuzhuang Mine
Liuzhuang is located in East China Coal Region. Faulting and fragile coals with low permeability makes in-seam drilling less effective.
• Top: Retreat longwall mine employing 220-280 m x 1500-1700
Liuzhuang : Pre-Drainage In-Seam Boreholes Current vs Recommended
meter panels
• Currently, cross-panel in-seam boreholes are drilled from the tailgate 80-110 m long on 6-m spacing .
• Boreholes probably stay in the lower half of the 4.5-m thick seam 13-1.
CURRENTPROCEDURE
6-m spacing
• Bottom: Recommended changes to in-seam borehole drilling strategy
• Directional drilling equipment
• 19-m borehole spacing
• 225-m long in-seam boreholes gshould be feasible.
• Top and bottom of seam drained
• Similar residual gas content RECOMMENDED
FUTURE PLAN
reduction with > CH4quantity/concentration..
19-m spacing
Gob Drainage: CURRENT• Top: Cross-measure boreholes are
drilled toward the retreating longwall face.
• Drill stations are spaced ~80 m alongDrill stations are spaced 80 m along tailgate entry, ramped up 10 m into overlying strata.
• Boreholes up to 110 m long and 50-90 mm diameter are angled up 15
CROSS-MEASURE BOREHOLES DRILLED FROM STATIONS ALONG
90 mm diameter are angled up 15-30° into the overlying rock strata.
• Stations are sealed and connected to vacuum.
DRILLED FROM STATIONS ALONG THE TAILGATE ENTRY • CMM is produced as panel is mined
through and gob created. It later is isolated to limit ventilation air contamination.
• Bottom: Drilling gallery is developed in rock about 18-25 m above seam.
• Gallery is located along tailgate side of panel.
• Gallery is sealed to limit air influx.
SUPERJACENT GALLERY DRIVEN ABOVE THE MINING SEAM
• Gallery is connected to vacuum system.
1500-1700m
30°
Gob Drainage : RECOMMENDED
10m
20m
20m
50m
220-280mIN- MINE GOB BOREHOLES DRILLED FROM STATIONS ALONG
• Current design could be replaced by long, 1000-m horizontal gob boreholes directionallyDRILLED FROM STATIONS ALONG
THE TAILGATE ENTRY1000 m horizontal gob boreholes directionally drilled from the ends of the panel.
• Could accomplish similar results.
PLAN VIEW
5m
SEAM 13-1
750-1000m
4m
30m
10mCROSS SECTION VIEW
750 1000m
• 75% fewer boreholes drilled (counting the tangential boreholes
Benefits of Recommended Cross-Seam and Gob Borehole Improvements
( g gindividually)
• 88% fewer drill setups, borehole collars, standpipes, and wellheads
• Same volume of methane recovered• Same volume of methane recovered
• Fewer wellheads minimizes potential for air intrusion into gathering system, thus improving recovered gas quality
• Fewer boreholes reduces methane drainage costs
• Potential for reduction in drainage time by reducing borehole spacing
• Fewer boreholes provides for reduced time required for drilling• Fewer boreholes provides for reduced time required for drilling
• Reduced residual gas contents improves mine safety
• Reduced residual gas contents enables increased coal production
Average Recovered Gas Quality (% CH4)
Current 5 -15
Recommended 40 - 70
Summary • Acquisition of geologic and reservoir• Acquisition of geologic and reservoir
properties allows mine operator to optimize methane drainage technique rather than use “trial and error.”
• Evaluate alternatives from drill bit to burner tip (e.g. drainage techniques, equipment, well heads, pipeline, safety q p , , p p , ysystems, surface facilities, and gas use options).
• Directional drilling will allow application g ppof modern methane drainage techniques tailored to site specific conditions.
• Provides geologic information such as coal thickness/thinning, identification of faults, intrusions, other anomalies, old workings, etc., prior to mining.