Bureau of Mines Report of Investigations/ 1974 

Degasification of the Mary Lee Coalbed 

Near Oak Grove, Jefferson County, Ala., 

by Vertical Borehole 

in Advance of Mining 

UNITED STATES DEPARTMENT OF THE INTERIOR 
UNITED STATES DEPARTMENT OF THE INTERIOR 

Rogers C. B. Morton, Secretary 

BUREAU OF MINES 

Thomas V. Falkie, Director 
This publication has been cataloged as follows: 

Elder, Curtis H 

Degasification of the Mary Lee coalbed near Oak Grove, 

Jefferson County, Ala., by vertical borehole in advance of 

mining, by C. H. Elder and Maurice Deul. [~ashin~ton] 

U.S. Bureau of Mines [I9741 

21 p. illus., tables. (u.S. Bureau of Mines. Report of investigations 7968) 

Includes bibliography. 

1. Degassing of coal. I. U.S. Bureau of Mines. 11. Deul, 

Maurice, jt. auth. 111. Title. (Series) 

TN23.U7 no. 7968 622.06173 

U.S. Dept. of the Int. Library 
CONTENTS 

Page 

Abstract ................................................................ 1 

Introduction ............................................................ 1 

Acknowledgments ......................................................... 2 

Background .............................................................. 2 

Drilling and completion ................................................. 2 

Gas and water production ................................................ 6 

Increase gas flow by stimulation procedures ............................. 9 

Summary and discussion .................................................. 12 

References .............................................................. 13 

Appendix A.--Geology .................................................... 14 

Appendix B.--Well histories of five wells in the Mary Lee coalbed near 

Oak Grove, Jefferson County, Ala ...................................... 15 

Appendix C.--Cumulative gas production for hole Nos . 3SW, 4SW, and 5C ... 20 

ILLUSTRATIONS 

1 . Map showing major structure axes in the Warrior coalfield of 

Alabama ......................................................... 3 

Outcrop map of coal producing stratigraphic groups in Jefferson 

County, Ala ..................................................... 4 

Plot showing location of drill pattern in sec 23, T 18 S, R 6 W, 

Jefferson County, Ala ........................................... 4 

Structure map on Mary Lee coalbed in vicinity of degasification 

test pattern T 18 S, R 6 W, Jefferson County, Alabama ........... 5 

Gamma ray, density, and lithologic logs of the Mary Lee coalbed 

overburden ...................................................... 6 

Gas production rates for degasification boreholes ................. 7 

Water production rates for degasification boreholes ............... 8 

Hydraulic fracture stimulation pressure and fluid injection 

charts .......................................................... 10 

Gas and water production for degasification borehole No . 3SW 

showing production rate increase after fracture stimulation ..... 11 

TABLES 

1 . Gas analyses ...................................................... 9 

B-1 . Bureau of Mines well No . 1NE ...................................... 15 

B-2 . Bureau of Mines well No . 2SE ...................................... 16 

B-3 . Bureau of Mines well No . 3SW ...................................... 17 

B-4 . Bureau of Mines well No . 4NW ...................................... 18 

B-5 . Bureau of Mines well No . 5C ....................................... 19 
DEGASIFICATION OF THE MARY LEE COALBED NEAR OAK GROVE, 

JEFFERSON COUNTY, ALA., BY VERTICAL BOREHOLE 

IN ADVANCE OF MINING 

C. H. Elder 1 and Maurice Deul 

ABSTRACT 

A 5-hole pattern was drilled from the surface at a site near Oak Grove, 

Jefferson County, Ala., to degasify the gassy Mary Lee coalbed in advance of 

mining. Gas and water production was monitored for 1 year, 4 months to allow 

gas flow to stabilize fully. A thickened water stimulation treatment was 

designed and applied in one hole of the pattern to evaluate this 

degasification technique for the Mary Lee coalbed. A gas production rate of 

70,000 ft3 /day after stimulation treatment indicates that the use of vertical 

boreholes coupled with hydraulic fracturing in advance of mining the Mary Lee 

coalbed would provide for more rapid degasification and could provide a 

possible source of natural gas. 

INTRODUCTION 

Degasification of coalbeds through vertical boreholes from the surface is 

part of the comprehensive methane control research program conducted by the 

Bureau of Mines. The technique has been applied experimentally at selected 

sites in most of the major bituminous coal producing areas in the United 

States. One such site is Jefferson County, Ala., where a mine is being 

developed in the Mary Lee coalbed. A degasification pattern of 5 holes was 

drilled at this site May 22 through July 11, 1971. Monitoring of gas and 

water production began September 16, 1971. Production from borehole No. 3SW 

was nearly continuous until June 28, 1973, when it was stimulated by hydraulic 

fracture to increase the rate of degasification of the coalbed. This study 

showed that the combined procedure should decrease the hazard of methane 

ignitions and explosions during mining. It also demonstrated the feasibility 

of providing supplemental sources of fuel through the recovery of methane that 

would otherwise be wasted to the atmosphere. 

Geologist. 

2 Supervisory geologist. 
ACKNOWLEDGMENTS 

The authors thank J. K, Weed, J. L. Huey, E. J. Files, and H. E. Kerley 

for providing maps, core data, and assistance in the field. The authors 

especially thank Kenneth 0. Austin of Calvert-Western Exploration Co., and 

H. E. Kerley, for review of the manuscript. 

BACKGROUND 

During 1971, underground coal mines in the United States vented nearly 

300 million ft3 of methane to the atmosphere each day. To dilute this gas to 

safe levels in the mines, more than 100 times this quantity of air had to be 

circulated through the mine workings. If some of this gas could have been 

removed from the coalbeds before mining started, mine ventilation costs could 

have been reduced, and a marketable energy product could have been conserved. 

Commercial quantities of gas have been produced from the Pittsburgh 

coalbed in Wetz-el County, W. Va. (1-2)3 - where production decline curve for a 

group of 20 wells on 1,500-foot spacing was typical and indicated no particular flow characteristics as a coal-gas reservoir. Research on degasification 

of the Pittsburgh coalbed by surface boreholes to reduce gas emissions into 

mine workings was pioneered by Spindler and Poundstone (13-14). Their results, 

coupled with known commercial production, indicated that degasification by 

vertical boreholes in advance of mining was encouraging but required further 

study in other coalbeds and using stimulation techniques. 

In 1971, a project was initiated to explore this degasification technique 

at test sites located in the major coal producing basins throughout the United 

States that are known to have highly gassy coalbeds. The objectives were to 

drill 5-hole patterns into selected gassy coalbeds, develop reservoir 

parameters, and evaluate well stimulation techniques for accelerating this 

degasification procedure. Several criteria were used to establish test 

sites: A history of gas emission into the mine workings, a site location in 

virgin coal 3 to 5 years in advance of mine development, a site remote from 

old mine workings, and at least one hole in each pattern to be stimulated. 

DRILLING AND COMPLETION 

The test site selected in the Mary Lee coalbed was in 23, T 18 S, R 6 W, 

near Oak Grove, Jefferson County, Ala., in the Warrior coalfield (figs. 1-3). 

The site is on a structural nose on the flank of the Sequatchie anticline 

(fig. 4). The test holes were drilled in virgin coal in an area not be mined 

for 3 to 5 years and remote from any old mine. A well spacing of 1,500 feet 

between holes was selected between the corner holes of a square pattern; a 

fifth hole was located at the center of the square. 

Drilling of the 5-hole test pattern began May 22, 1971, and was completed 

July 11, 1971. Nine-inch-diameter holes were drilled with standard rotary 

3Underlined numbers in parentheses refer to items in the list of references 

preceding the appendixes. 
I wiley I dome 

Sequatchie anticline 7 

Warrior syncline // 

Blue creek ant 

syncl ine 

icline 

Warrior field 

LEGEND 

4 Anticline 

Syncline 

Dome 

0 - 20 40 

Scale, miles 

drilling equipment. Drill 

cuttings were removed by 

circulating air or water 

during drilling. The holes 

were drilled to the top of 

the coalbed and cased to 

provide for open hole 

completion in the coal 

interval. Open hole 

completion provides the 

maximum exposure of the 

coalbed to production of gas 

with minimal chance of 

formation plugging by 

invasion of well cement. 

When drilling to the 

top of the coalbed was 

completed, the holes were 

logged with geophysical 

logging equipment (fig. 5). 

Gamma ray, neutron, density, 

and caliper logs are used to 

determine hole condition 

before casing the hole and 

to evaluate porous zones in 

the strata overlying the 

coalbed that may contain 

water or gas. 

The holes were cased 

with 7-inch-OD steel casing 

cemented from bottom to surf ace with expanding type 

cement. Seven-inch-OD 

casing was selected so that 

the degasification boreholes FIGURE 1. - Map showing maior structure axes in the could be used for other Warrior coalfield of Alabama. 

purposes after mine development has bypassed them, such as power and communication system entry into the 

mine, bulk supply point for rock dust, and for gob degasification of longwall 

panels or after pillar recovery. 

After casing was set, the coalbed was cored cutting a 6-inch hole and 

retrieving a 4-inch core. Coring was done with air to limit possible physical 

damage to the coalbed that would inhibit the flow of gas during the degasification period. 

Immediately following coring, the coalbed was tested for formation pressure and flow rates of water and gas. For this purpose a test tool and 

?ackers on the bottom of a string of drill pipe were inserted into the hole, 
Blount County 

Section 

LEGEND 

0 5 10 

U €ZEl Black Creek group 

Scale, miles 

FIGURE 2. - Outcrop map of coal producing stratigraphic 

groups in Jefferson County, Ala. 

KEY PLAN 

----- 

-- 

Section 

Elev451.4 3 1 

tiydmulic fra

Section Section 

27 

1 26 T 18 R6W 

OSca

FIGURE 3. - Plot showing loca

sec 23, T 18 S, R 

A la. 

tion and plotted (appendix C) . The low production from holes 

Nos. lNE, 2SE, and 4NW is 

attributed to low variable 

permeability and some formation damage from drilling 

fluids blocking the flow of gas. 

There is an increase of 

permeability with time of 

dewatering (1J). This may 

account for the continued 

increase in production rate for 

holes Nos. 3SW and 5C. Production data from this pattern and 

other coalbeds indicate that 

stable flow rates require long 

periods of time to allow for 

,, dewatering of the coalbed and 

GAMMA RAY. BULK DENSITY, g/crn3 achievement of steady-state 

API UNITS flow. Low initial production 

FIGURE 5. - Gamma ray,density,and lithologic logs suggests that all degasificaof the Mary Lee coalbed overburden. tion holes should be stimulated 
the No. 3SW hole, up to the time of stimulation, was 56 psi over a period of 

16 months. During this period, production rate was still increasing and had 

not completely stabilized. 

Borehole No. 3SW has produced the greatest quantity of gas of the boreholes in the pattern, 1,684,700 ft3 during the 16 months of production before 

stimulation. Contrary to many oil and gas reservoirs, production from the 

Mary Lee coalbed had a very low initial production rate that increased with 

time and an expanding collection radius resulting from dewatering of the 

coalbed. 

Analyses of water sarnples from borehole No. 3SW showed 1,530 ppm 

dissolved solids, of which 9 ppm is calcium, 0.3 ppm iron, and 700 ppm 

chloride (as NaC1). No magnesium or sulfates were detected. Table 1 gives 

corresponding gas analyses. The gas from the Mary Lee coalbed has a heat 

content of 970 to 990 Btu. 
KEY 

- No. 3SW 

No. 2 SE 

----- No. 4 NW 

No. 5 C 

FIGURE 7. - Water product ion rates for degas if ication boreholes. Dai ly average computed on 

2-wee k product ion interva Is. 
TABLE 1. - Gas analyses 

INCREASED GAS now BY STIMULATION PROCEDURES 

Date 

4/72 

7/3/73 

10/17/73 

A coalbed generally has low permeability and the rate of desorption of 

gas from coal around a degasification borehole depends on the surface area 

exposed. There is need to increase the permeability of coal around the 

borehole and to extend the drainage radius. This can be done by thickened 

water stimulation. This process is not explosive and does not create a 

shatter zone. Experience has shown that it produces vertical fractures or 

openings and extends existing fractures or joints (4, 1, 9). The fractures 

are opened 0.2 to 0.4 inches and packed with propping sand, thus increasing 

permeability along the fracture and extending the drainage radius several 

hundred feet for gas flow. 

The gas emission rate at hole No. 3SW had been monitored long enough to 

establish a production rate trend against which the effect of a thickened 

water stimulation procedure could be evaluated. 

Sample 

{i 

(2 

5 

The following criteria were used in the design of the stimulation 

procedure : 

Injection rate .............................. bbl/min.. 

Formation thickness .............................. ft.. 

Elastic modulus of coalbed ......................p si.. 

Formation permeability ........................... md.. 

Formation porosity .............................. ct.. 

Bottom hole treatment pressure ..................p si.. 

Formation pressure ............................... si.. 

Reservoir fluid viscosity ........................ cp.. 

Type of gel (Halliburton) ...........................* 

Gel concentration ........................ lb/ gal.. 

Well bore radius ................................. ft.. 

Damage ratio ......................................... Size of prop sand .............................. mesh.. 

Concentration of prop sand ................... lb/gal.. 

Stimulation fluid volume ........................g al.. 

Pump truck capacity .................... hydraulic hp.. 

BoreholeC02 

3SW 

3SW 

3SW 

3SW 

3SW 

2.9 

2.6 

0 

CQ 

0,196.20.01 

.195.9 

88.6 

89.1 

96.7 

C2b 

.01 

.08 

.08 

.O1 

CBh 

- 

- 

0.018 

,019 

Tr. 

C4HI0 

- 

- 

0.002 

,002 

- 

C5H12 

- 

- 

0.0003 

.0003 

- 

H2 

0.01 

.01 

3.9 

3.9 

0 

He 

0.26 

.28 

- 

- 

-22 

0, 

0.0 

.1 

.2 

.2 

0 

Inerts 

N, and 

A 

3.4 

3.6 

4.3 

4.1 

3.0 
The stimulation design plan of Halliburton Well Services Co. was used to 

calculate the following computer simulation output (8): 

A fracture treatment using 10,000 gallons fracture fluid and 6,000 pounds 

of 10 to 20 mesh propping sand was chosen. 

For this stimulation experiment, high-pressure (2-718-inch) tubing with 

a tension packer in the string was run in the hole. The packer was set at 

988 feet in the 7-inch well casing with the bottom end of the tubing at the 

midpoint of the coalbed. One thousand six hundred gallons of water was 

pumped into the coal with increasing pressure to achieve formation break and 

start fracture propagation. The coalbed broke at 800 psig (fig. 8). Continuous fracture propagation was established at 1,100 to 1,200 psi pumping 

pressure and a steady 10 bbllmin injection rate. The water was followed with 

10,000 gallons of gelled-water fracturing fluid with 112 lb of propping sand 

per gallon at start. After 2 to 3 minutes, the sand injection rate was 

Fracture fluid 

volume, gal 

10,000 

15,000 

Fracture 

width, in 

0.24 

.26 

0 4 8 12 16 20 24 28 32 36 40 44 48 

TIME, min 

Sand 

lb 

5,600 

7,400 

Production 

increase 

11.7 

15.6 

4,000 

. - 3,000 

In 

a 

w' 

rK 

3 2,000 v, 

8 

rK 

FIGURE 8. - Hydraulic fracture stimulation pressure and fluid injection charts. 

Propped fracture 

length, ft 

255 

377 

a 

1,000 - - 

- \ - 

I, 11111,1,1,111 I IIIII, 

11 I 1 I I I~IIIIIIIII 

- Pressure test - 

- 

- 

- 

- 

- 

-Initial fracture 

at 800 psi 

- 
FIGURE 9. - Gas and water production for degasification borehole No. 3SW showing product ion rate increase after fracture st irnu lat ion. 

per gallon at start. After 2 Lo 3 minutes, the sand injection rate was 

increased to 314 lb/gal. The fracture propagated normally during injection. 
Following the stimulation the well was shut in for 18 hours, then the 

packer was unseated and the 2-718-inch tubing was removed from the borehole. 

The hole was swabbed free of fluid, and 30 feet of sand accumulation at the 

bottom of the hole was removed with a sand pump bailer. After cleanout, the 

water pump was reinstalled in the hole, and production monitoring was resumed. 

All of the fracturing fluid was recovered from the formation with pumping. 

The gas flow rate increased, after the fracturing process, from 4,520 to 

5,000 ft3/day to a maximum rate of 90,000 ft3/day in 11 days. During the 

next 7 months the flow rate declined normally. The gas flow rate levelled off 

at f70,000 ft3/day--a fold increase in flow rate from the borehole (fig. 9). 

This production increase is very close to the calculated production increase. 

SUMMARY AND DISCUSSION 

Production history indicated that coal in the Mary Lee coalbed has a 

variable but low in-place permeability. A stimulation procedure, such as 

hydraulic fracturing, was needed to extend the collection.radius by 

increasing the permeability of the coal around the borehole. The propped 

induced fractures provided a larger, more permeable, collection radius for gas 

production and increased the gas production rate fourteen fold. 

With properly spaced, stivulated degasification boreholes over the entire 

coal mine property, the coalbed could be materially degasified, with time, 

prior to mining. This would reduce the cost of mine ventilation, make the 

mine safer, and increase mine productivity. After mining intercepts the holes, 

the boreholes can serve as comunication, power-drop, and rock-dust supply 

stations. The holes can also be used to help ventilate gob area following 

roof collapse with pillar extraction or longwall mining (5). Finally, if 

sufficient gas is produced, sale or use of the gas could recover the cost of 

drilling and completion of the degasification boreholes. 
REFERENCES 

1. Cervik, J. Behavior of Coal-Gas Reservoirs. BuMines TPR 10, April 1969, 

10 PP 

2. Cervik, J., and C. H. Elder. Removing Methane From Coalbeds in Advance 

of Mining by Surface Vertical Borehole. Proc. Conf. on the Underground 

Mining Environment. Univ. of Mo., Rolla, Mo., Oct. 27-29, 1971, 

pp. 229-240. 

3. Culbertson, W. C. Geology and Coal Resources of the Coal-Bearing Rocks 

of Alabama. U.S. Geol. Survey Bull. 1182-B, 1964, 75 pp. 

4. Daneshy, A. A. True and Apparent Direction of Hydraulic Fractures. Soc. 

Petrol. Eng., AIME, Paper No. SPE 3226, 1971, pp. 1-9. 

5. Elder, C. H. Use of Vertical Boreholes for Assisting Ventilation of 

Longwall Gob Areas. BuMines TPR 13, May 1969, 6 pp. 

6. Farmer, I. W. Engineering Properties of Rocks. E. and F. N. Spon Ltd., 

London, 1968, pp. 1-180. 

7. Fraser, C. D., and B. E. Pettit. Result of a Field Test To Determine the 

Type and Orientation of a Hydraulic InducedfFormation Fracture. J. 

Petrol. Technol., May 1962, pp. 463-466. 

8. Halliburton Services. The Fracbook ~esign/~ato Manual for Hydraulic 

Fracturing. Published by Halliburton Services, Duncan, Okla., 1971, 

pp. 1-111. 

9. Hubbert, M. King, and D. G. Willis. Mechanics of Hydraulic Fracturing. 

Trans. AIME, v. 210, 1957, pp. 153-166. 

10. Irani, M. C., E. D. Thimons, T. G. Bobick, M. Deul, and M. G. Zabetakis. 

Methane Emission From U.S. Coal Mines, A Survey. BuMines IC 8558, 

1972, 58 pp. 

11. Kissell, F. N. The Methane Migration and Storage Characteristics of the 

Pittsburgh, Pocahontas No. 3, and Oklahoma Hartshorne Coalbeds. 

BuMines RI 7667, 1972, 22 pp. 

12. Semrnes, D. R. Oil and Gas in Alabama. Ala. Geol. Survey Spec. Rept. 15, 

1929, 408 pp. 

13. Spindler, G. R. Degasification of Coal Seams. Am. Min. Congr., Coal 

Mine Modernization, 1953, pp. 206-220. 

14. Spindler, G. R., and W. N. Poundstone. Experimental Work in Degasification of the Pittsburgh Coal Seam by Horizontal and Vertical Drilling. 

Trans. AIME, v. 223, 1962, pp. 37-47. 
APPENDIX A.--GEOLOGY 

The two coal-producing formations in the Warrior coalfield of Alabama are 

the Parkwood Formation of Mississippian and Early Pennsylvanian age and the 

Pottsville Formation of Pennsylvanian age; the Pottsville Formation is the 

major coal producer (3, - 12). 

The Pottsville Formation consists of interbedded gray shales, gray sand 

shales, thin-bedded sandstone, coarse- to medium-grained massive sandstone, 

and several bituminous coalbeds. 

The Mary Lee coal group, a part of the Pottsville Formation, has the 

largest reserves in the Warrior field and consists of the Ream, Jagger, Blue 

Creek, Mary Lee, and New Castle coalbeds. 

The Mary Lee coalbed includes four seams that may coalesce and/or pinch 

out. The seams range from 2 to 70 inches in thickness, and the intervening 

shales .range from a few inches to 20 feet. 

The Warrior field is situated north and west of the Appalachian Mountains 

on the Cumberland Plateau. The field is bounded on the southeast by a major 

thrust fault. The coalfield was structurally folded forming the Coalburg 

syncline, Sequatchie anticline, Warrior syncline, and Wylie Dome (figs. 1-2). 

The test site is located on a small anticlinal nose on the southeast 

flank on the Sequatchie anticline (figs. 1, 3-4). The Mary Lee coalbed 

outcrops 5-1/2 miles to the northeast of the test site on the southeastern 

flank of the Coalburg syncline. Field mapping indicates the expected major 

cleat direction in the coal to be N 70" E and according to J. L. Huey the 

major rock joint direction (in the overburden) to be N 75" W. 
APPENDIX B.--WELL HISTORIES OF FIVE WELLS IN THE MARY LEE COALBED 

JEFFERSON COUNTY. ALA . 

TABLE B.1 . . Bureau of Mines well No . 1NE (~~.1/2, sec 23. T 18 S. R 6 

NOTE.--Formation pressure was measured at 396 psi o 

Date started ....................... Date completed ..................... .. .................. Depth to coal ft 

.. Coal elevation ................. ft 

Total depth .................... ft .. 

.. .............. Surface elevation ft 

Casing: 

Total depth ...................... 

Length of 12-3/4-in-diam 

casing ...................... ft .. Length of 7-in-diam casing ... ft .. Gas shows. on drill stem 

test of coalbed ..............ft.. 

Water .......................... ft .. 

Rotary to depth ................ ft .. Bit size ....................... in .. Interval cored ................. ft .. Core size ...................... in .. 

Core recovered ..............

DO ........................

Core returned to Pittsburgh, 

Samples : 

Water .....................

May 22. 1971 

June 10. 1971 

1.067.7 

-681.7 

1. 090 

449 

1. 059 

11 

1, 059 

1,045-1, 076 

65-70, 805-810. 

1, 070 

1, 063 

9 

1,063-1, 076 

5 

Gas .......................

Tests : 

Water .....................

Gas ......................

Logs : 

Density ................. .d

Neutron .................. d

Gamma ray ............... .d

Caliper .................. d

. Drill stem test No 1 .......

Date of drill stem test .....

Maximum shut-in pressure ....

Date monitoring equipment 

1 installation completed .....

Date pumping equipment insta

..................

1 . completed 

1 test . Monitoring started F

electric power ins tallation . 
TABLE B-2.--Bureau of Mines well No . 2SF (CSL, sec 23. T 18 S. R 6 

Date started ....................... 

..................... Date completed 

.. Depth to coal .................. ft 

Coal elevation ................. ft .. Total depth .................... ft .. Surface elevation .............. ft .. Casing: 

Total depth .................. ft .. Length of 10-3/4-in-dim 

casing ...................... ft .. Length of 7-in-dim casing ... ft .. Gas shows, coalbed after 

completion ........................ Water .......................... ft .. 

June 26. 1971 

July 2. 1971 

1,063.3 

-632.3 

1. 081 

431 

Rotary to depth ...............

Bit size ......................

Interval cored ................

Core size .....................

Core returned to Pittsburgh. P

Logs : 

Density .................. dep

Neutron .................. dep

Gamma ray ................ dep

................. Caliper .dep

.*...

Maximum shut-in pressure 

Date monitoring equipment 

installation completed .......

Date pumping equipment installa

completed ....................

I I 

NOTE.--Formation pressure measured at 389 psi; monitoring started February 24. 197

power installation . 
TABLE B.3 . . Bureau of Mines well No . 3SW (CSL, SIJ~. sec 23. T 18 S. R 6 

Date started ....................... Date completed ..................... Depth to coal .................. ft .. Coal elevation ................. ft .. Total depth .................... ft .. 

.. .............. Surface elevation ft 

Casing: 

Total depth .................. ft .. Length of 10-3/4-diam 

casing ...................... ft.. 

Length of 7-in-diam casing ... ft .. Gas shows ..................... .ft .. 

.. Water .......................... ft 

Rotary to depth ................ ft .. Bit size ....................... in .. Interval cored ................. ft .. Core size ...................... in .. 

1 completed .................

in pressure recorded too low . 

July 2. 1971 

July 11. 1971 

1.075.5 

-625.5 

1. 093 

450 

1. 056 

11 

1. 056 

80.1.075.5 

500-665.1. 077 

1. 065 

8-314 

1.065-1. 093 

5 

- 

..............

Core recovered 

Samples : 

Water .....................

Gas .......................

Tests: 

Water .....................

Gas .......................

Logs : 

Density ................ .de

Neutron ................ .de

Gamma ray ............... de

................. caliper de

Drill stem test No . 2 .......

.....

Date of drill stem test 

Maximum shut-in pressure ....

Date monitoring equipment 

installation completed .....

Date pumping equipment insta

NOTE.--Drill stem test tool had faulty valve; shutSeptember 16. 1971 . 
TABLE B.4 . . Bureau of Mines well No . 4 NW (SE. NW. SW. sec 23. T 1

... pp 

....................... Date started 

Date completed ..................... Depth to coal .................. ft .. Coal elevation ................. ft .. Total depth .................... ft .. Surface elevation .............. ft .. Cas ing : 

Total depth .................. ft .. Length of 10-3/4-diam 

casing ...................... ft .. Length of 7-in-diarn casing ... ft .. Gas shows, coalbed after 

........................ completion 

Water .......................... ft .. 

.. Rotary to depth ................ ft 

.. ....................... Bit size in 

Interval cored ................. ft .. Core size ...................... in .. 

June 19. 1971 

June 25. 1971 

1. 067 

-6 20 

1. 092 

447 

Core returned to Pittsburgh. 

Samples : 

Water ......................

Gas ........................

Tests: 

Water ......................

Gas ........................

Logs : 

Density ................. dep

Neutron ................. dep

Gamma ray ............... dep

Caliper ................. dep

Maximum shut-in pressure .....

Date monitoring equipment 

installation completed ......

Date pumping equipment 

......

installation completed 

Core recovered ............... .pct .. 1 1001 

NOTE.--Formation pressure measured at 396; monitoring started Feb . 24, 1972. afte

installation . 
WeJeJeJO 4 

wwwwo b 

OOOO* m nnnn 4 

4444 

1111 n 

0000 4 

mmmm 4 

. . ..... . . ..... . UUUU.4 . . '44wwwV) . . . a- *. CCCC . . uuuu . . aaaa 

Q)Q)Q)Q) 

. . aaaa. . . ..... . . ..... . . .....u. . . ... .cud. . . ... .baa a . . . -3EQ)uQ) . . . . .wau~u . . . .~).da~a,a . . .... a34 . . . k~aaq . . ... . . aaJ E.4 E: .... . . 0 3 0 dM0 '30 . . .....dC a; . . . I-dC d . . -. .UkOMO . . . h 3 0.4 d-4 . . (d .CUU.dU 

. AC k k cn.4 am u 0 a C4 Ed 

k -4 k k rda 04 34 

a V)U -4 3 E; a; UV)..C~E~E 

(d(dV)arar(d(d.darV)arV) 3UMC3ZC3U XOCOC 

0 (d rd -4 (d .4 

I4 za a 

. . . . . . . . u uu *u 

w ww .w . . . . . . . . . . . . . . . . .M . . .d . . .r( .. .V) . . cdk *E *oar 

.a. &I.. 

.r( . ew . . .a -cdcdg. I ..r( . . -3 .am . . .\*la)* 

l .dP . I ..r(d . . 0 .I@. . C4 *bO u . 0.. 

aw .w d 

a0 -0 -0 a b~ r(. 

CdC3U 4u.r(uoa 

cdk 

€ 

0 0 

Fr a 
APPENDIX C.--CUMULATIVE GAS PRODUCTION FOR HOLE NOS. 3SW, 4NW, and 5C 

Date I No. 3SW. ft3 

September 16 - 30 

October 1 - 15 

16 - 31 

November 1 - 15 

16 - 30 

December 1 - 15 

16 - 31 

1972: 

January 1 - 15 

16 - 31 

February 1 - 15 

16 - 29 

March 1 - 15 

16 - 31 

April 1 - 15 

16 - 30 

May 1 - 15 

16 - 31 

June 1 - 15 

16 - 30 

July 1 - 15 

16 - 31 

August 1 - 15 

16 - 31 

September 1 - 15 

16 - 30 

October 1 - 15 

16 - 31 

November 1 - 15 

16 - 30 

December 1 - 15 

16 - 31 

1973: 

January 1 - 15 

16 - 31 

February 1 - 15 

16 - 28 

March 1 - 15 

16 - 30 

April 1 - 15 

16 - 30 

May 1 - 15 

16 - 30 

June 1-15 

16 - 27 

See footnotes at end 

2,001 

6,318 

10,175 

14,210 

18,130 

22,470 

26,480 

29,435 

Meter stolen 

No. 4NW, ft3 

4,250 

9,250 

20,000 

34,750 

53,000 

76,000 

100,775 

120,000 

1123,000 

142,000 

167,000 

199,000 

239,750 

280,000 

323,000 

366,500 

412,000 

455,000 

498,000 

540,000 

584,000 

621,000 

663,500 

704,000 

748,000 

793,000 

843,000 

893,000 

943,225 

996,000 

1,055,000 

1,109,500 

1,174,500 

1,243,500 

1,248,000 

- 

- 

1,341,430 

1,406,490 

1,481,412 

1,552,780 

1,626,920 

1,684,700 

of tabulation. 

Well shut in for 

pressure monitoring. 

No. 5C, ft3 
APPENDIX C.--CUMULATIVE GAS PRODUCTION FOR HOLE NOS. 3SW, ~Nw, AND 

5C--Continued 

Date 

1973--Con. 

July 1 - 15 

16 - 31 

August 1 - 15 

1.6 - 31 

September 1 - 15 

16 - 31 

~ctober 1 - 15 

16 - 30 

November 1 - 15 

16 - 30 

December 1 - 15 

16 - 31 

1974: 

January 1 - 15 

16 - 31 

February 1 - 15 

16 - 28 

March 1 - 15 

16 - 31 

l~orehole No. 3SW was 

Jan. 16-31, 1972. 

 o ore hole No. 3SW was hydraulically stimulated for greater production 

June 28-31, 1973. 

No. 4NW, ft3 

69,000 

71,190 

73,285 

75,290 

77,545 

79,010 

81,440 

84,945 

88,000 

91,160 

94,200 

97,480 

100,285 

103,740 

106,665 

109,260 

112,215 

115,050 

days during monitoring 

No. 3SW, ft3 

2,373,520 

2,687,081 

3,683,081 

4,102,485 

4,905,985 

5,722,485 

6,524,210 

7,370,210 

8,081,485 

8,951,985 

9,761,985 

10,635,985 

11,516,985 

12,480,485 

13,274,485 

13,903,985 

14,700,485 

15,437,760 

shut in for 12 

No. 5C, ft3 

216.000 

221,650 

248,000 

274,500 

301,500 

330,500 

359,225 

381,000 

397,000 

412,000 

432,000 

456,225 

483,000 

516,000 

550,500 

585,500 

628,000 

671,500 

period