Pre-mine recovery of coalbed methane
using surface directional wells
– the project of the Polish Geological Institute - NRI
Janusz JURECZKA
Polish Geological Institute – National Research Institute
Upper Silesian Branch, Sosnowiec
Polish Geological Survey
Table of contents
Introduction: World → Poland → USCB
USCB – coalbed methane issues
Key issues for the development of CBM production/recovery
Project of the Polish Geological Survey – „Mysłowice-Wesoła” Coal Mine
Summary
Coalbed methane (CBM) – natural gas, stored within the coal by the process of adsorption
One of the main alternative energy sources:
production: USA, Australia, Canada, China, India
largest resources: Russia, USA, China, Australia, Canada, Indonesia
0
10
20
30
40
50
60
198
9199
0199
1199
2199
3199
4199
5199
6199
7199
8199
9200
0200
1200
2200
3200
4200
5200
6200
7200
8200
9201
0201
1
U.S. Energy Information Administration
(www.eia.gov)
2008 – 56 billion m3
United States coalbed methane production
1989–2011
Coalbed methane (CBM) – natural gas, stored within the coal by the process of adsorption
One of the main alternative energy sources:
production: USA, Australia, Canada, China, India
largest resources: Russia, USA, China, Australia, Canada, Indonesia
Main categories of CBM (USA-Canada-Australia):
VCBM – Virgin Coalbed Methane (from virgin coal seams)
CMM – Coal Mine Methane
AMM – Abandoned Mine Methane
CBM categories in Poland:
CBM as the main mineral commodity (=VCBM)
CBM as the accompanying mineral commodity (=CMM )
Coalbed methane in Poland
CBM
~2-5 billion m3
CBM
~15? billion m3
CBM
230-250 billion m3
Coalbed Methane Resources in USCB
19%
16%
33%
32% demonstrated res.
of CMM
34,6 Bm3
(29 fields)
demonstrated res.
of Virgin CBM
26,5 Bm3
(6 fields)
prognostic resources
54,2 Bm3
speculative resources
52,8 Bm3
„Economic” Recoverable Resources: (demonstrated, prognostic i speculative)
ca.168,1 Bm3
Total Resource Potential – appr. 230–250 Bm3 which includes:
„economic” + „sub-economic” (11,0 Bm3 ) + shallow biogenic CBM (5,2 mld m3) + CBM below 1500 m, CBM in unassessed
areas, CBM from coal seams with methane content below 2,5 m3CH4/t
Data source:
Polish Geological Institute
Methane emission
from coal mines
Methane !!!
- Hazard!
- Waste?
- Valuable energy resource!
Upper Silesian Coal Basin
29 – active mines
Emissions, Recovery and Utilization of CBM
22% 11%
67%
Uncaptured methane
(direct emission)
Captured methane
which is used
Captured methane
which is emitted
178,60 88,14
561,50
Methane captured – 266,74 MMm3
Data source:
Central Mining Institute
2012
Measured volume of methane (methane released and recorded by mines) – methane
contained in ventilation air + methane captured – 828,24 MMm3 (21 mines)
Unmeasured methane sources – „non-methane” and „low methane” mines + extracted
coal and barren rock consisting of 5–10% of measured methane – ca. 40-80 MMm3
Total volume of methane emission per year: 680-720 MMm3
(1 CH4 = 21 CO2, --> 15.1 Bm3 CO2)
Methane released from:
USCB – Distribution of methane content with increasing depth:
model cases
Key issues for the development of CBM production/recovery
Improvement of current in-mine demethanization + pre-mine drainage
(in new coal fields or mining levels):
The first pilot project run by PGI – wells: Wesoła PIG-1 and Wesoła PIG-2H
Further development of experimental studies – surface wells or in-mine boreholes
Evaluation of coal properties for CBM – desorption, diffusion and migration of methane (adsorbed on coal matrix) during the process of methane flow/recovery:
Adequate scope of analyses – currently, only coal quality analyses are made
Present understanding of the CBM reservoir – limited to methane content of coalbeds
Coal properties as a reservoir rock for methane:
Problem – very poor or lack of understanding of the reservoir properties
Permeability – key reservoir parameter that controls gas flow
Sorption capacity – ability of coal to store gas which results from adsorption and absorption processes under given pressure and temperature condition in the reservoir
Methane content of coal seams:
Current measurements – total methane content multiplied by a factor of 1.33
Problem – no possibility of determining a portion of total gas content which desorbs from coal
USBM method – residual gas is measured and desorbed gas is estimated
PROJECT
Pre-mine drainge of coal seams using surface boreholes – assessment
of its application under the reservoir and mining conditions
of the Upper Silesian Coal Basin
along with the drilling of an experimental well
(executed as a function of the Polish Geological Survey)
National Fund of Environmental
Protection and Water Management
(funding)
Ministry of Environment
(supervision)
Project objective:
Determine the feasibility of
pre-mine drainage of coal seams along with methane production
using surface wells within the area of active mines,
with a possible application of hydraulic stimulation of coal seams
Stage I (06.21012 – 06.2013):
Pre-feasibility study:
research conducted as preparations for drilling an experimental well, which includes:
review of gassy coal deposits; complimentary study of geological, mining, environmental and legal
conditions; selection of an experimental well location; laboratory analyses of coal collected from
the coal mine; geological work program
Stage II (07.2013 – 12.2014):
Drilling and evaluation of an experimental well (dual lateral, horizontal drilling) :
drilling an experimental well with tests and analyses, as well as preparation of the final geological
report
Basic criteria for location of CBM directional wells
No Geological criteria Mining criteria Environmental criteria
1.
Depth to coal seams selected for pre-
mine drainage: up to 900–1200 m
Coal seams are not mined in the vicinity of
the planned drillings, and their geometry
and properties are well understood
Low degree of urbanisation in the area
2.
Methane content of coal seams: greater
than 4.5 m3/t, but, optimally, not less
than 7–8 m3/t
Favorable layout of the planned longwalls
allowing for directional drilling,
Lack of environmentally sensitive areas
3.
Coal seam thickness: minimum 2.0 m,
but, optimally, not less than 3–4 m
Distance from directional drilling to active
mine workings minimum 100-150 m
Distance from the experimental well to
residential houses: at least 300 m (opt.
800 m)
4.
Coal seams with constant thickness,
dipping monoclinally (unfolded), without
partings, splittings or washouts
No existing mine workings or gobs along
the well trajectory
Presence of paved roads in the area
5.
Coal seams tectonically undisturbed,
without faults (very small faults < 0.5 m);
dipding towards the vertical well
Possibility of drilling in-mine investigation
boreholes for obtaining coal samples in the
vicinity of the planned wells, and they are
to be drilled from the existing and
accessible workings
The area for building a drilling site
which covers ca. 1 ha
6.
No aquifer is present at the top or base of
the selected seam
Possibility of collecting coal samples from
the selected seams in other parts of the
mine
Possibility of produced water disposal
7. Presence of impermeable Carboniferous
overburden (optional)
Coal seams are scheduled to be mined not
earlier than 3-5 years before the start of
pre-mine drainage methane recovery
Presence of gas pipelines in the vicinity
(optional)
coal properties which control CBM reservoir quality
include: permeability , porosity,
sorption capacity
???
Chosen locations
Kompania Węglowa S.A.
1. KWK „Sośnica-Makoszowy”
Ruch „Sośnica”
2. KWK „Szczygłowice-Knurów”
Ruch „Szczygłowice”
Katowicki Holding Węglowy S.A.
3. KWK „Mysłowice-Wesoła”
d. kop. „Wesoła”
Jastrzębska Spółka Węglowa S.A.
4. KWK „Budryk”
1
2 3 4
1000 m
600m
600m
Main types of horizontal wells
„Pinnate” horizontal well drilling (www.earthenergyreserves.com)
One drilling site
Two drilling sites combination of vertical and horizontal wells
(intersected well)
Wesoła PIG-1 and Wesoła PIG-2H – planned trajectories
456 m
138 m
„Mysłowice-Wesoła” Coal Mine
„Mysłowice-Wesoła” Coal Mine, Az Part – 501 coal seam
Geological cross-section – Az Part
3D Model – Wesoła PIG-1 and Wesoła PIG-2H wells Top Surface of
Carboniferous
318
Coal Seam
405/2
Coal Seam
501
Coal Seam
510
Coal Seam
Wesoła PIG-1
– vertical well 1000 m
Stratigraphy:
0,0 – 28,0 m Quaternary
28,0 – 1000,0 m Upper Carboniferous
(coal-bearing formations)
28,0 – 788,0 m Mudstone Series
788,0 – 977,1 m Upper Silesian Sandstone Series
965,7 m – the 501 coal seam (3,65 m)
977,1 m – the 510 coal seam (11,05 m)
977,1 – 1000,0 m Paralic Series
Drilling time:
Spud date – 11.12.2013.
Completion date – 12.01.2014.
Well section Wellbore
diameter
Casing size
(inches) Depth
Conductor 20” 7 m
Intermediate casing 12 ¼” 9 5/8” 154 m
Production casing 8 ½” 7” 1000 m
(total depth)
Drilling and casing program of the Wesoła PIG-1 vertical well
Coring depth: 591.00 – 1000.00 m
7” casing string contains a fibre glass section at depth of 977.10–968.46 m
Wesoła PIG-1 – data gathering and field tests
Field laboratory – mudlogging and desorption
Wireline well logging
Temperature log
Caliper
Gamma Ray
Density log
Acoustic log (dipole sonic)
Microresisitivity scanner (XRMI)
Cement bond log
Well tests – determination of permeability and reservoir pressure in 501-510 coal seams A. Injection tests with downhole pressure monitoring:
- injection fall-off test
- step rate test
- fracture reopening test
or
B. Diagnostic Fracture Injection Test DFIT
Objective – determination of reservoir parameters: absolute permeability, reservoir pressure, fracture pressure inculding – fracture opening, fracture closure, and fracture reopening (with estimation of geomechanical parameters, e.g. formation strength and stress)
Wesoła PIG-1 – data gathering and field tests Field laboratory – mudlogging and desorption
Wireline well logging
Temperature log
Caliper
Gamma Ray
Density log
Acoustic log (dipole sonic)
Microresisitivity scanner (XRMI)
Cement bond log
Well tests – determination of permeability and reservoir pressure in 501-510 coal seams A. Injection tests with downhole pressure monitoring:
- injection fall-off test
- step rate test
- fracture reopening test
or
B. Diagnostic Fracture Injection Test DFIT
Objective – determination of reservoir parameters: absolute permeability, reservoir pressure, fracture pressure inculding – fracture opening, fracture closure, and fracture reopening (with estimation of geomechanical parameters, e.g. formation strength and stress)
Vacuum degassing
(containers with balls)
Desorption testing using USBM
canister desorption method
0
10
20
30
40
50
60
70
80
90
100
Field laboratory Stationary laboratory
10 cm
40 cm
20 cm
30 cm
Petrophysical parameters:
Vertical and horizontal permeability
Total, effective and dynamic porosity
Porosity and permeability in fractures
Archiving
Other tests
USBM method
continued
Residual gas measurement
Chemical composition of gas
Adsorption capacity of coal for methane
(sorption isotherms)
Physical and chemical analyses of coal
Thermal maturity (vitrinite reflectance) and
petrographic composition of coal
Wesoła PIG-1 – laboratory tests
Core sampling program:
- 14 coal seams (660,55 – 977,10 m)
- 31 samples for aforementioned tests
- incl. 3 samples from 501 seam and 11 samples from 510 seam
Wesoła PIG-2H
– directional well 1918 m MD (904,0 m TVD)
Stratigraphy (MD):
0,0 – 23,0 m Quaternary
23,0 – 57,0 m Neogene – Miocene
57,0 – 1918,0 m Upper Carboniferous
(coal-bearing formations)
57 – 158 m Cracow Sandstone Series
158 – 896 m Mudstone Series
896 – 1155m Upper Silesian Sandstone Series
1155 – 1318 m Paralic Series
1318 – 1918 m Upper Silesian Sandstone Series
1318 – 1918 m: 510 coal seam (600 m)
Intersect point (Wesoła PIG-1) – 1312,8 m MD
Drilling time:
Spud date – 08.02.2014.
Completion date – 22.03.2014.
Well section Wellbore diameter Casing size
(inches) Depth
Conductor 20” 9 m
Surface casing 17 ¼” 13 3/8” 113 m
Intermediate casing 12 ¼” 9 5/8” 501 m
Final casing 8 ½” 7” 1192 m MD
(below 510 c. seam)
Open hole 6” 1918 m MD
(total depth)
Drilling and casing program of the Wesoła PIG-2H horizontal well
Wesoła PIG-2H
drilling trajectory
Stage II – further work
Production tests – horizontal section, 510 coal seam
Production test before hydraulic fracturing: June – July/August
Hydraulic fracturing August/September
Production test after hydraulic fracturing: September – October
Final geological report
07.04.2014. 07.04.2014.
Summary
2. Pre-mine drainage of coal seams:
- early recovery of valuable energy commodity
- extraction of coal in more favorable mining and economic conditions
(reducing methane hazard – improved work safety, significant reduction
of extraction costs)
- reduction of methane emissions to atmosphere
(decrease of green house effects).
1. Poland coal basins – so far coalbed methane has not been the subject of
commercial recovery.
Horizontal drilling technology – new prospects for recovery and utilization of
coalbed methane (mostly in USCB).
3. Key issues for the development of recovery and utilization of coalbed
methane:
- understanding of those coal properties which control CBM reservoir quality
- implementing measurements of residual and desorbed methane content.
Thank you for your attention
