relationship to CBM (coalbed methane) a a aa aa acoloradogeologicalsurvey.org/wp-content/uploads/2013/08/rtv3n3.pdf · Coals are derived from ancient peat deposits that formed in

Prior to the nineteenth cen-tury, wood was humankind’sprimary source of thermal

energy. But wood could not effi-ciently supply the great amount ofthermal energy required to fireblast furnaces, smelters, steamlocomotives, and other large facili-ties—the sort of facilities andmachines that increasingly domi-nated America’s industrial growth.Coal could. A relatively modestpile of coal could supply the sameamount of energy as a giant stackof wood.

In the early 1800s, Americansburned coal in small amounts—usually as a domestic fuel. As thepace of industrialization quick-ened, America’s appetite for coalgrew more ravenous. In the threedecades from 1800 to 1830,

America’s annual coal productionincreased tenfold, from about100,000 tons to one million tons.But that was just the beginning. By1885, the nation mined 110 milliontons each year. By 1900, the figurehad more than doubled to 243 million tons a year. Currently, aswe move into the 21st century, thenation’s annual coal productionhas risen to more than 1,100 mil-lion tons a year.

The majority of America’s coalin the early part of the industrialrevolution came from the Appala-chian Mountains. Colorado didnot become a coal producer untilthe 1870s. By 1900, Colorado pro-duction was nearly 7.5 milliontons a year. Nearly half of thatproduction was used in the CF&ISteel Mill in Pueblo, which wasbuilt in 1880 by General WilliamPalmer, the founder of the Denver& Rio Grande Railroad. Currently,Colorado produces approximately30 million tons of coal annually.

Usage of mined coal haschanged since the nineteenth cen-tury from being an important com-ponent in the production of steelto generating electricity by burn-ing the coal in boilers to runstream driven turbines. Electricutilities now consume about 90percent of the nation’s annual coaloutput.

Underground mining for anycommodity has always been arisky activity, especially in the early19th and 20th centuries. Injury andloss of life from underground rockfall, fire, mishandling of explo-sives, accidents with mining toolsand machines, and “bad” air wasan all too common occurrence.

Colorado Geological Survey ROCKTALK Vol. 3, No. 3 1

COLORADO GEOLOGICAL SURVEY

V O L U M E T H R E E , N U M B E R T H R E E J U L Y , 2 0 0 0

Focus on Coalbed Methane

Publications...................................6

Outreach Calendar......................11

Earth Science Week..............................12

Inside this issue

Continued on page 2

coalbed methane — colorado’sworld class commodity

A story of turning a dangerous and sometimesdeadly byproduct of coal mining into a usefuland environmentally friendly energy source.aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa a aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa a aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa a aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa a aaaaaaaaaaaaaaaa a aaaaaaaaaaaa a aaaaaaaaaaa a aa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa a aaaaaaaaaaaa aaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaCBM

wellSchematic cross section showing conven-tional surface mining technology andrelationship to CBM (coalbed methane)production well

Underground coal mining undoubt-edly has suffered the heaviesthuman toll over other miningcommodities such as gold, silver,precious stones, copper, etc. becauseof an additional hazard unique tocoal: storage of highly explosivemethane gas in the microporestructure of coal seams. The releaseof methane from coal in under-ground coal mines and the conse-quent explosion of this gas hasresulted in horrific losses of life.One particular example occurredin 1910 when a methane explosionin the Primero Mine, located sometwenty miles west of Trinidad,Colorado, killed more than 100 men.

United States private industryand government in the late 1960s,both individually and collectively,initiated research programs direct-ed toward making coal miningsafer by developing methods ofde-gassing coal seams prior tomining. These early pilot pro-grams carriedout in the Midwest andAppalachiaeventuallyturned a“lemon intolemonade.”

By usingstandard oiland gas fieldrecovery andproductiontechnologies,this dangerouscoal gas (mostlyhigh qualitymethane) couldbe recoveredand utilized.Industry, partic-ularly AmocoProduction Company (now BP-Amoco) initiated programs todevelop methane gas from subsur-face coal seams in several of thenation’s sedimentary basins regar-dless of mining activity associated

with the coalbed sequence. Becauseof Amoco’s pioneering efforts, theSan Juan Basin of southwesternColorado and northwestern NewMexico eventually became the“Crown Jewel” in coalbed methane(CBM) production. This basin’sproduction stream of CBM gas out-shines the rest of the world’s sedi-mentary basins in CBM production.

CBM extraction has, in 30years, changed primarily from amine safety matter into a signifi-cant factor in both U.S. natural gasproduction and gas reserve base.Currently, CBM accounts for about7 percent of U.S. dry natural gasproduction.

Colorado CBM productiontotaled about 390 billion cubic feetin 1999, which placed Colorado insecond place nationally behindNew Mexico’s 570 billion cubicfeet. By way of perspective, U.S.natural gas production totalednearly 19,000 billion cubic feet in

1999. The Gulfof Mexico Fed-eral Offshoreand the State ofTexas were thenation’s leadingproducers ofnatural gas withvolumes respec-tively of about4,800 billioncubic feet each.

The major-ity of Colo-rado’s CBMproduction hascome fromFruitland For-mation coalseams (UpperCretaceous inage) in the San

Juan Basin. In recent years, CBMgas production has also expandedsignificantly in the Colorado por-tion of the Raton Basin of southcentral Colorado and northeastNew Mexico.

Colorado Geological Survey ROCKTALK Vol. 3, No. 32

colorado’s hot commodity cont. from p. 1

Field Notes from the Director

C olorado’s CoalbedMethane (CBM) is thetopic of this quarter’s

RockTalk. With increased nat-ural gas prices, increased CBMproduction, and residentialgrowth increasing in areaswhere natural gas productionoccurs, coalbed methane is atopic of great interest to Colo-rado’s gas and oil companies,state and local planners andregulators, and citizens.

Estimates from theNational Petroleum Councilindicate that as a nation, ourdemand for natural gas willincrease from 22 trillion cubicfeet (TCF) to 30 TCF in thenext decade. Consumption ofnatural gas within Coloradoin 1998 totaled 312 billioncubic feet (bcf). Coloradoproduced 705 bcf that sameyear, meaning our state con-sumed about 44 percent ofour production. Coloradoranks 6th in the nation interms of dry gas production.

For a variety of reasonsincluding geologic and mar-ket conditions, natural gashas become the most impor-tant part of the gas and oilindustry within Colorado,and CBM dominates the nat-ural gas picture. From 1988until 1999, natural gas pro-duction in Colorado steadilyincreased, while oil production

Continued on page 7

The “natural gas” delivered toColorado’s homes, retail busi-nesses, and industries is actu-ally a mixture of hydrocarbongases composed almost en-tirely of methane, but contain-ing small amounts of otherheavier hydrocarbon gases,including ethane, propane, bu-tane and pentane. Methane iscomposed of a molecule of onecarbon atom and four hydro-gen atoms (CH4).

DID YOU KNOW?

Coals are derived from ancientpeat deposits that formed inboth fresh water and brack-

ish-water swamps (above). A widerange of vegetation such as trees,shrubs, grasses and other plantsthrives in swampy or marshy areas.The continuous accumulation ofthis vegetation in the swampseventually forms peat. When peatis buried by thousands of feet ofoverlying rock layers such assands and muds, a process whichcan take millions of years, it isconverted to coal with the aid ofelevated geothermal temperaturesand burial pressures. These conver-sion processes compact the vegeta-tive layers, driving off water and

enhancing the transformation ofsome organic material into gases,specifically methane and carbondioxide (below). The original peatcomposition becomes more deplet-ed in hydrogen and oxygen whilethe relative concentration of carbonincreases (graph, p. 4). This trans-formation causes the original peatto become more dense, harder, andenriched in carbon over timebecause of increased geothermaltemperature and burial pressure.Each coal designation (lignite,bituminous, and anthracite) relatesto the depth of burial and associ-ated pressure and temperatureregime of the original peat accumulation.

Most of Colorado’s abundantcoal deposits were formed incoastal swamps along the westernedge of an extensive inland seaapproximately 50 to 70 millionyears ago during Late Cretaceousand early Tertiary times (map, p. 4). When we think about modern-day swamps, we look at


how coal is formed

Fresh waterswamp

River sandsand gravels

Brackish-waterswamp

Marineshales

OKEEFENOKEE SWAMPENVIRONMENT

FRUITLAND FORMATIONENVIRONMENT

Open Ocean

Beach and dunes

Peat Marinesandstone

Diagram of a swamp showing peat, sand and shale accumulations in a cross section view

Residualproducts

• Coal• Methane

Organic debris• Peat

Pressure

Heat

Time

Expelled by- products• Water• Methane• Carbon dioxide

Formation of coal from peat over time by heat and pressureModified from Ayers et al., 1990

“Snapshot in time” of active coalswamp facies from drawing ofColorado coal swamp of 80 millionyears ago Braginetz from SP 35

the Okeefenokee Swamp in Floridaas a prime peat-producing envi-ronment. Colorado coals wereformed in swamps much closer tothe shoreline than the Okeefeno-kee Swamp is to the AtlanticOcean (see drawing of swamp onp. 3). The paleogeography (ancientgeography) was markedly differ-ent then from what it is today. Oneof the reasons we know that isbecause of the extensive coaldeposits that exist in the state.Back then, vast areas of temperateclimate coastal swamps flourishedfor several million years along thewestern edge of a shallow marinesea that covered central NorthAmerica from northern Canada tosouthern Mexico (lower left). Pre-sent day Colorado and the otherRocky Mountain states are situat-ed along the former shorelineswamps and shallow seas. Thoseswamps produced the ancient peatdeposits that are today’s coalfields in Colorado (map, p. 5).

Most of the methane incoals is adsorbed orattached inside the

micropore spaces or microscopicholes in the coal. Water containedwithin the fractures (cleats) exertspressure on the adsorbed methane,keeping it from moving out ofthese micropores into the fracturesor cleats in the coal. By removing alarge volume of the water in thecoal, the methane gas is free todesorb or move from the coalmicropores to the cleats where itcan flow more freely through thecoal (diagram, p. 5).

Many conventional gas reser-voirs—those found in sandstonesor limestones—have the potentialto produce gas almost immediately


Diagram showing the change in elemental composition of coal during burial

how methaneis stored in

the coalsC

RETA

CEO

US

SEAW

AY

C A N A D A

U N I T E D S T A T E SSANJUANBASIN

G R E E N L A N D

A L A S K A

80°

70°

60°

50°

40°

30°M E X I C O

Colorado

Increasing depth and time of burialIncreasing amounts of carbon

Incr

easin

g am

ount

sof

oxy

gen

and

hydr

ogen Lignite

Bituminous

Anthracite

Peat

Paleogeographic map of the Late Cretaceous Seaway in North America


once they have been drilled andcompleted properly if they containvery little water. The measure of agood conventional gas reservoir isthe quantity of gas that will beproduced in a given amount oftime. Some conventional gas reser-voirs do have water in them. Thegreater the amount of water, theless efficient the gas productionwill be, because the water inhibitsthe flow of gas. The water also hasto be collected, separated from thegas, and disposed of in some man-ner, thus adding to production costs.

CBM reservoirs are different inmost cases. Large volumes ofwater exerting the pressure neces-sary to keep methane adsorbed orconfined in the coal microporesmust be removed from the coalbefore the methane itself is finally

Colorado coal regions

SEDGWICK

PHILLIPS

Y U M A

K I T C A R S O N

C H E Y E N N E

K I O W A

PROWERS

B E N T

B A C A

CROWLEY

O T E R O

L A S A N I M A S

H U E R FA N O

P U E B L O

E L P A S O

L I N C O L N

WASHINGTON

E L B E R T

ARAPAHOE

ADAMS

MORGAN

L O G A N

W E L D

DOUGLAS

TELLER

L A R I M E R

BOULDER

JE

FF

ER

SO

N

GILPIN

CLEAR CREEK

P A R K

C U S T E R

FREMONT

S A G U A C H E

CHAFFEEG U N N I S O N

LAKE

SUMMIT

G R A N D

J A C K S O N

COSTILLAC O N E J O S

ALAMOSARIO GRANDE

MINERAL

HINSDALE

A R C H U L E TA

E A G L E

R O U T T

P I T K I N

L A P L ATA

D O L O R E S

S A N M I G U E L

SANJUAN

OURAY

M O N T R O S E

D E L T A

M E S A

G A R F I E L D

R I O B L A N C O

M O F F A T

M O N T E Z U M A

SOUTHPARK

REGION

CANON CITY REGION

RATONMESA

REGION

NORTHPARK

REGION

GREEN RIVER REGION

UINTAREGION

DENVERREGION

DENVERREGION

SAN JUAN

RIVER REGION

Shading corresponds toareas containing coal-bearing geologic formations

EXPLANATION

Cleats—Fracturescaused bydrying of peatduring coalformation

Water filled cleats keep methanetrapped in micropores

Methanemoves towell boreafter wateris removed

Coal matrix blocks—containmicropores filled with methane

Diagram showing methane gas recovery from coal

free to flow. The water has to bepumped from the coal using thefamiliar pumpjack surface equip-ment (shown in left of center inphoto above). Pumps are neededto lift significant amounts of water“uphill” to the ground surface,which can be as much as 4,000 feetabove the producing coals. Once asignificant amount of water hasbeen pumped out of the coals, thegas will flow by itself to the sur-face where it is transported tomarket via a pipeline (center rightin photo above).

Though often produced inlarge quantities at the beginning ofa well’s life, the amount of waterpumped from a coalbed reservoirwill generally decrease over timeduring all three stages of the lifeof a coalbed methane well asshown in the graph below. If thereis a sufficient amount of methanestored within the coal, the vol-umes of methane gas being pro-duced will increase over time dur-ing the dewatering and stableproduction stages of the typicalwell. At some future time, the


GGG aaa sss

WWW aaa ttt eee rrrTime

Vo

lum

e

111Dewatering

Stage

222Stable

ProductionStage

333DeclineStage

CBM well surface equipment

Diagram showing production stages of a typical coalbed methane wellFrom Kuuskraa, 1990

How to Order CGS

PublicationsHOW TO ORDER PUBLICATIONS

Mail: Colorado Geological Survey,

1313 Sherman Street, Room 715, Denver, CO 80203

Phone: (303) 866-2611Fax: (303) 866-2461,

E-mail: [email protected]

Website: www.dnr.state.co.us/geosurvey

VISA® and MasterCard®

accepted. Prepayment required.

SHIPPING AND HANDLINGPlease contact the CGS for

shipping and handling costs.

DISCOUNTS

Available on bulk orders.

Call for a complete publication list

CCBBMM PPUUBBLLIICCAATTIIOONNSS

Information Series 35Selected References Related toCoalbed Methane in the GreaterGreen River, Piceance, PowderRiver, Raton and San Juan Basins

$10.00

Open-File Report 79-3Content of Methane in Coal fromFour Core Holes in the Raton andVermejo Formation, Las AnimasCounty, Colorado $15.00

Open-File Report 80-2Deep Coal Bed Methane Potentialof the San Juan River Coal Region,Southwestern Colorado $30.00

continued on p. 11


has been steady or slightlydecreasing. In 1998, CBM madeup about 54.5 percent of Colo-rado’s total gas production.According to national figures,about 56 percent of the total sup-ply of proven coalbed methanereserves in the lower 48 statesare located in the San Juan Basin.This important basin, much ofwhich is located within the bor-ders of Colorado, is truly aworld class gas basin. Recently,new natural gas pipeline devel-opments are also allowing RatonBasin CBM to reach consumers.

Production of CBM is notwithout its difficulties. As you’llread here, CBM has long been a

safety hazard to coal miners.Developing our CBM resourcesrequired new ways of thinkingabout exploration and productiontechniques. Predicting and man-aging CBM is different than con-ventional oil and gas drilling.And throughout Colorado CBMbehaves as a natural geologichazard.

The Colorado Geological Sur-vey (CGS) studies coalbed meth-ane for a variety of reasons. In1994, CGS released a statewidealert to citizens about coalbedmethane as a geological hazard,since approximately one-third ofthe state is underlain by coal.The CBM does escape from shal-low coal seams and this color-less, odorless, and non-toxic gas

can be explosive if it is trappedby structures on the seeping out-crop. Historic reports of activeCBM seeps go back decades inmany places in Colorado.

CGS has been active in CBMstudies since 1978, when our ear-liest CBM publications reportedon mine-gas emissions andexplosions. Subsequent gas con-tent measurements of coal coresamples helped document an in-place CBM resource that is greaterthan 100 TCF. CGS studies con-tinue today to help delineate thedetailed structure of the San Juanand other CBM basins, and toassist state and local governmentofficials as well as industry andcitizen workers who are trying tosafely produce CBM.

Field Notes continued from page 2

��

��

��

amount of recoverable methane inthe reservoir will decrease andproduction will decline steadily tothe economic limit of the well.This is represented as the declinestage in the diagram on p. 6. Thisproduction profile of a CBM wellis the reverse of what it is for most

Colorado’s Coalbed Methane ContributionIn 1993, coalbed methane represented about 3 percent of the nation’s totalgas production. At present, coalbed methane production has grown to about7 percent of U.S. natural gas production. Colorado’s coalbed methane pro-duction in 1993 totaled about 125 billion cubic feet, about 17 percent of thiscomponent of the nation’s total gas production. In 1999, Colorado’s produc-tion of nearly 390 billion cubic feet of coalbed methane represented a 35percent contribution. Clearly these numbers indicate Colorado’s growingimportance to the national energy equation as a source of clean burning natural gas.

Most U.S. natural gas isproduced, sometimes along

with oil, by drilling in theearth’s crust into pockets ofporous rocks, usually sand-stone, limestone or dolomite,where natural gas wastrapped thousands to millionsof years ago. The gas trappedin subsurface coalbeds com-positionally differs somewhatfrom “conventional” naturalgas accumulations. The hydro-carbon component of coalbedgas is almost always puremethane. “Conventional” natural gas reservoirs oftencontain significant amounts of

the heavier hydrocarbongases.

Gas recovery:conventional vs coalbed

��

��

��

conventional gas wells in whichthe methane or gas productionrate begins at its highest pointafter the well is completed andprogresses through a steadydecline throughout the life of thewell (below). It is easy to under-stand why it is difficult to estimate

the gas rate profile for a CBM wellwhen the initial production ratesfor gas are low and productionrates for water are high. The actualvolume of gas that will be pro-duced, as well the length of timefor which that rate continues canvary substantially in CBM wells.

The San Juan Basin of southwest Colorado andnorthwest New Mexico is a natural resourcemecca for coal and coalbed methane. Most of

the economically important coalbeds in this basin arein the Late Cretaceous-age Fruitland Formation. High-quality coal has been mined at or near the surfacesince the late 1800s. For as long as the mines wereoperated, the deadly presence of methane in the coalcaused coal mine explosions resulting in loss ofhuman life and property damage.

The earliestreference toCBM in the SanJuan Basin isfrom an 1892article in theDurango Boardof Trade thatstates that Pro-fessor ArthurLakes of theColorado Schoolof Mines recog-nized coal oiland natural gaswithin fourmiles of Duran-go. Lake wasinstrumental incausing the firstpetroleum wellto be drilledbetween 1890and 1900 near Durango. After the well reached adepth of 1,500 feet, drilling equipment was lost in thehole and the investors ran out of money, putting anabrupt end to that well. (Emery C. Arnold and ThomasA. Dugan, 1971, Western Oil Reporter, August, 1971, p. 24). In 1902, gas was discovered in a well just out-side of Durango at a depth of 940 feet, possibly fromthe Fruitland Formation coals. (Amoco ProductionCompany, 1994, Pine River Fruitland Coal OutcropInvestigation, p. 1). The well probably was never pro-duced commercially.

While fledgling gas and oil wells were beingdrilled, coal mining continued to grab the mediaheadlines. Mine explosions and fires were commonand many miners lost their lives from deadly methanebuildups in the mines both in the San Juan Basin

mines as well as in mines throughout the rest of Colo-rado. One report from the Bayfield Blade on January 11,1924 is particularly significant in terms of an earlyrecognition of the potential value of this methane. Thearticle reported that a “gas gusher” measuring onemillion cubic feet of gas per day rushed out of theTendick Mine located approximately 10 miles north-east of Bayfield. This gusher was initiated after adynamite shot was detonated about 200 feet insidethe mine in a seam of coal. The roar from the rush of

gas exiting themine could beheard over a halfa mile away. Thearticle acknowl-edged the flowas methane gas, asource for light-ing and heating,but was particu-larly prescient inthis quote: “...ifthe heavy flowholds up and away can befound to stop theflow, we willhave a valuableresource in thisnatural gas.”

The earliestrecorded CBMwell, the Stano-

lind Oil and Gas Company Ute D-1 well, was drilledin 1951 just outside Ignacio, Colorado. The coals, dis-tributed throughout 400 to 500 feet of the FruitlandFormation, were perforated through steel casing thatwas placed in the hole. Solidified nitroglycerine,packed in the hole at the depth of the Pictured CliffsSandstone, which underlies the Late Cretaceous Fruit-land Formation coalbeds, was detonated to producefractures. The initial flow rate reported from this dis-covery well was 1.9 million cubic feet of gas per day,which is a respectable initial rate for a CBM well.Unlike other wells in the basin, these early FruitlandCBM wells produced very little water initially. As thewater production increased over time, the early wellswere plugged because the costs of handling the watermade the wells uneconomic with gas prices of $0.11


Fruitland coal in the San Juan Basin with two monitoring wells

SAN JUAN BASIN —Birthplace of coalbedmethane production in colorado

per thousand cubic feet. By comparison, today’s pricesin June 2000 vary between $3.25 and $4.00 per thou-sand cubic feet, allowing more monetary leeway in pay-ing the costs for pumping and disposing of the water.

For over 20 years, the shallow gas targets were thesandstone and not the coals in the Fruitland Forma-tion. Fruitland coals had been mined historicallyalong the outcrop, but it would take some industryingenuity and technology to recognize the potential ofthe coalbeds as methane-producers alone. Coal com-pletions in subsurface wells were done only as a lastresort or in combination with sandstone completions.The exploration seed for CBM from the actualcoalbeds was sown again in 1977 by Stanolind’s suc-cessor, Amoco Production Company. The AmocoCahn Gas Com No. 1, drilled just over the border inNew Mexico, was completed as a Fruitland Formationcoalbed methane well. Although the well had an initialproduction rate of less than 100 thousand cubic feet ofgas per day, an order of magnitude less than the UteD-1, it was heralded as the CBM discovery well forthe San Juan Basin because it demonstrated the poten-tial for methane production solely from coalbeds. Eversince then, industry scientists have conducted exten-sive tests on the coalbeds, their gas content, and on

methods to efficiently and economically produce themethane gas.

Today, the San Juan Basin in Colorado is undergo-ing another wave of CBM drilling, prompted by theincrease in gas price and the recognition that more gasis stored in the coals than previously recognized. Thelargest producer to date, the Amoco Gardner A-1, hasproduced over 20 billion cubic feet of gas, a huge vol-ume for a single domestic gas well. Total productionfrom the coals in the Colorado portion of the San JuanBasin is about 2.1 trillion cubic feet of gas. By compar-ison, the next closest producing reservoir in the basin,developed by conventional gas wells, is the MesaverdeFormation, which has only produced about 712 billioncubic feet of gas, one-third the volume of the CBMproduction.

Estimates for CBM resources in the San Juan Basinof Colorado and New Mexico hover around 50 trillioncubic feet, of which Colorado may be expected tohave 40 to 50 percent. Clearly, these resource num-bers, coupled with record high gas prices, explain thefeverish pace at which CBM wells are being drilled.

Colorado’s second CBM success story takes placein the Raton Basin in the south-central part of thestate, near the town of Trinidad (see map on p. 5).


The methane content of a coalbed can be mea-sured in the field with core samples from verti-cal boreholes. This method, commonly referred

to as “desorp-tion”, measuresthe gas releasedby the coal corein an airtight con-tainer. The result-ing gas contentdetermination ofthe coal per unitweight can thenbe extrapolatedto estimate thesubsurface gasresource of thesampled coalbed.

Desorptiontests run on Ver-mejo Formationand Raton For-mation coalbedscollected from

four U.S. Geological Survey test holes in 1978 in thecentral Raton Basin west of Trinidad, Colorado clearlyestablished that these coalbeds had high CBM produc-

tion potential.Several explor-atory drill holeswere completedduring the1980s. Commer-cial develop-ment of thisidentified CBMresource, how-ever, was stalledfor nearly 25years because ofa lack of gastransportationout of the basin.In 1994, Colo-rado InterstateGas (CIG) work-ing with AmocoProductionRaton Basin coalbed methane well

RATON BASIN — finally producing CBM after years of delay

Company and Meridian Oil Inc.,fixed the region’s gas marketingproblem by laying approximately35 miles of pipeline from theirmain line near Trinidad to thecoalbed methane fields. This line,which CIG refers to as the Pick-etwire lateral, is capable of trans-porting 30 million cubic feet of gasa day. Access to markets triggeredan active CBM exploration anddevelopment program in the basinthat continues to the present. In1997, CIG built a second line, the115-mile Campo lateral, whichadded an additional 100 millioncubic feet per day of natural gastransportation capacity out of thebasin. In December 1999, El PasoEnergy Corp. announced plans foran additional interstate pipeline totransport gas between the RatonBasin and Moore County in theTexas Panhandle. This proposedproject involves the construction

of 185 miles of 24-inch pipeline,with an initial capacity of 175 mil-lion cubic feet of gas per day.

The Colorado Oil and GasConservation Commission reportsthat at year-end 1999 approximate-ly 400 wells were producing 80million cubic feet of gas per dayfrom Vermejo and Raton Forma-tion coalbeds in the Raton Basin.Cumulative CBM productionstood at 56 billion cubic feet. Ever-green Resources is the most activeoperator with 252 gas wells con-nected to pipeline at year-end1999. Other active players in thebasin include Shenandoah EnergyInc., KLT Gas Inc., Sonat Explo-ration, J. M. Huber, and Petro-glyph Energy Inc. Active develop-ment in the basin is expected tocontinue during 2000 driven inlarge part by Evergreen’s recentannouncement of plans to drill 100additional wells by year-end.


Some coal basins in Coloradodo not have established eco-nomic CBM resources. The

Uinta and Green River coalregions in the western part of thestate (map on p. 5), located withinthe Piceance and Sand WashBasins have been drilled to test theLate Cretaceous–Early Tertiarycoals. Low gas content, possiblydue to depth of burial of the coals,and/or low permeabilities thatrestrict producing rates, have pre-vented economic gas recoveries.Compared to the producingdepths in the San Juan Basin ofless than 4,000 feet, coal targets of

9,000 foot depth in the Uinta andGreen River regions pose severeeconomic limitations for explora-tion drilling.

Coals in the Denver Coalregion, east and northeast of Den-ver, also referred to as the DJBasin in petroleum references,have been penetrated by thou-sands of wells that were drilled todeep gas and oil reservoirs. TheCBM potential appears minimal atthis point in time. However, risinggas prices and continued demandfor natural gas may spur develop-ment of these poorer quality, deep-er, and thinner coalbeds.

other CBM opportunities in colorado

DID YOUKNOW?In the U.S. about 46 percentof natural gas is used in theindustrial sector, providingenergy for everything fromprocessing foods and minedmineral resources to manu-facturing chemicals forfarmers and ranchers.Generating electricity con-sumes about 15 percent.Another 15 percent is usedin the commercial market—for heating and coolingoffice buildings, schools,shopping malls and cookingin restaurants. Most of theremaining 24 percent isused in the residential sec-tor, for home heating,clothes drying, dish wash-ing, cooking, and air condi-tioning.

As with any gas or oil well,regulations have beenestablished and are

enforced to protect surface water,vegetation, wildlife, and subsur-face groundwater. CBM reservoirs

CBM ENVIRONMENTAL issues

have the added distinction of pro-ducing large quantities of water.Some coals contain potable waterthat can be used for irrigation andlivestock. Other coals producemore saline, and thus non-potable,waters that must be disposed ofproperly. Water disposal frequent-ly involves reinjecting the pro-duced waters back into a deeper,porous rock layer. This water thenbecomes a resource for somefuture use. Regardless of the qual-ity of the produced water, it is notmixed with the shallow aquifersthat serve as a source of drinkingwater.

references forthis issue

Amoco Production Company, 1994,Pine River Fruitland coal outcrop

Cont. on p. 12

11

Colorado GeologicalSurvey

1313 Sherman Street, Room 715

Denver, CO 80203

Phone: (303) 866-2611Fax: (303) 866-2461

Website: www.dnr.state.co.us/geosurvey

Colorado Geological Survey Staff

Vicki Cowart, State Geologist

James A. Cappa, Mineral Resources

Vince Matthews, Senior Science Advisor

David C. Noe, Engineering Geology

Randal C. Phillips, GIS and Technical Services

Vickie B. Pierce, Administration and Outreach

Matt Sares, Environmental Geology

Knox Williams, Colorado Avalanche Information Center

Administration and OutreachMelissa Ingrisano, Katie KellerLynn,

Dori Vigil

Avalanche Information CenterDale Atkins, Nick Logan, Scott Toepfer

Engineering Geology and Land Use

Karen Berry, Celia Greenman, Monica Pavlik,Roger Pihl, Pat Rogers, Jim Soule,

Jon White

Environmental GeologyJohn Neubert, Ty Ortiz

Geologic MappingBob Kirkham, Beth Widmann

GIS and Technical ServicesCheryl Brchan, Matt Morgan, Larry Scott,

Jason Wilson

Mineral FuelsChris Carroll, Tom Hemborg, Laura Wray

MineralsJohn Keller, Beth Widmann

Division of Minerals and Geology

Department of Natural Resources

State of Colorado

August 9–11Colorado Oil and Gas Assoc.(COGA) 12th Annual RockyMountain Natural Gas Strat-egy Conference and Market-ing Fair, participant, exhibit,Laura Wray, (303) 866-3519

September 1–4Taste of Colorado, ColoradoMining Exhibit Foundationexhibit, informational/educa-tional materials, participant,Guy Johnson, (303) 969-0365

September 15–17Denver Gem and Mineral

Show, publication sales, exhib-it, informational/educationalmaterials, Carol Smith, (303) 233-2516

September 24–27“Abandoned Mined Land2000” Annual Conference,Association of AML Programsspeaker, exhibit, LorettaPineda, (303) 866-3819

September 29Colorado Science TeachersConvention, exhibit, speaker,Marie Sullivan, (719) 598-4976

Upcoming Events Involving CGS

Open-File Report 80-4The Coal Bed Methane Potential ofthe Raton Mesa Coal Region, RatonBasin, Colorado $15.00Open-File Report 80-5Conservation of Methane from Col-orado Mined/Minable Coal Beds: AFeasibility Study $10.00Open-File Report 80-7Methane Drainage Plan Using Hor-izontal Holes at the Hawk’s NestEast Mine, Paonia, Colorado $5.00Open-File Report 81-4Coal Bed Methane Desorption Data

$35.00Open-File Report 81-6Coal Bed Methane Potential of theSand Wash Basin, Green River CoalRegion, Colorado $25.00Open-File Report 82-1Coal Bed Methane Potential of thePiceance Basin, Colorado $30.00Open-File Report 82-4Southern Ute/Department of EnergyCoalbed Methane Test Wells $5.00Open-File Report 94-2Coalbed Gas Composition in UpperCretaceous Fruitland Formation,

San Juan Basin, Colorado and NewMexico $10.00Resource Series 30Geologic and Hydrologic Controlson Coalbed Methane: Sand WashBasin, Colorado and Wyoming

$10.00Resource Series 31Coalbed Methane in the Upper Cre-taceous Fruitland Formation, SanJuan Basin, New Mexico and Colo-rado $20.00Resource Series 33Spanish Peak Field, Las AnimasCounty, Colorado: Geologic Settingand Early Development of a CoalbedMethane Reservoir in the CentralRaton Basin $8.00

NNEEWW CCOOAALL PPUUBBLLIICCAATTIIOONNSS

Information Series 54Colorado Mineral and Mineral FuelActivity, 1999 $6.00Open-File Report 00-12Demonstrated Reserve Base for Coal inColorado: Yampa Coal Field $4.00Resource Series 38Availability of Coal Resources inColorado: Somerset Coal Field,West-Central Colorado $9.00

Publications continued from page 6



COLORADO

GEO LO GI C AL SU RVEY

Colorado Geological Survey1313 Sherman Street, Room 715Denver, CO 80203

PIA 341100040

BULK RATEU.S. POSTAGE PAIDDenver, Colorado

Permit No. 738

investigation: Southern RockiesBusiness Unit, Amoco Produc-tion Company, Denver, Colorado,September 15, 1994.

Cappa, J. A., Carroll, C. J., and Hem-borg, H. T., 1999, Colorado min-eral and mineral fuel activity:Colorado Geological SurveyInformation Series 54, 32 p.

Dugan, T. A., and Williams, B. L.,1988, History of gas producedfrom coal seams in the San JuanBasin in Fassett, J E. (ed.), 1988,Geology and coal-bed methaneresources of the northern SanJuan Basin, Colorado and NewMexico: Rocky Mountain Associ-ation of Geologists, Denver, Colorado, p. 1–9.

Fassett, J. E., 1988, Geometry anddepositional environment ofFruitland formation coalbeds,San Juan Basin, New Mexico andColorado: Anatomy of a giantcoal-bed methane deposit in Fas-sett, J. E. (ed.), 1988, Geology andcoal-bed methane resources ofthe northern San Juan Basin, Col-orado and New Mexico: RockyMountain Association of Geolo-gists, Denver, Colorado, p. 23–38.

Kuuskraa, V.A., 1990, Summary ofcoalbed methane technology andeconomics in coalbed workshop:Gas Research Institute, Denver,Colo., March, 1990.

Lamarre, Robert A., 2000, Graphicdisplays

Gas and Oil in Colorado—PetroleumProducts Are Everywhere!

An interactive CD-ROM for middle and high schoolstudents and teachers

A new educational CD-ROM, Special Publication 50, will be availableto all middle and high school teachers in Colorado for free! This inter-active CD, created to meet the standards for earth science education,describes the geologic and technical aspects of the petroleum industryand its economic benefits to the state’s economy. Students and teach-ers alike can play interactive games and learn geologic conceptsthrough video clips, animations, and photographs. A teenagerdescribes the fundamentals of petroleum formation and extraction,focusing upon gas and oil activities in Colorado. The CD includes thefollowing information: careers in the petroleum industry; educationalresources in the form of publications, organizations, and pertinentwebsite addresses; classroom experiments relating to petroleum con-cepts; environmental issues handled by the industry; and a glossaryof petroleum terms.Contact CGS with your mailing address for advance notification of thisCD-ROM: (303) 866-2611 or e-mail [email protected]. This is boundto be a popular item for teachers and students!

The Colorado Geological Survey ishosting three free public field tripsduring EARTH SCIENCE WEEK,October 8—14, 2000.

Monday, October 9—“Geology,Water Quality, and AvalancheHazards of the Silverton–OurayArea”Wednesday, October 11—”Bounc-ing Boulders, Rising Rivers, andSneaky Soils: A Primer to Geo-

logical Hazards and EngineeringGeology Along Colorado’s FrontRange”Friday, October 13—“The Geo-logic Story of the GlenwoodSprings Area”

Contact CGS with your mailingaddress for advance notification andregistration: (303) 866-2611 or [email protected] 40 participants on each trip.

Geology Field Trips!!! Everyone is welcome!!

relationship to CBM (coalbed methane) a a aa aa acoloradogeologicalsurvey.org/wp-content/uploads/2013/08/rtv3n3.pdf · Coals are derived from ancient peat deposits that formed in

Documents