Glossary of Terms

Appalachian Basin — The area of the United States comprised of those portions of West Virginia, Pennsylvania, Ohio, Maryland, Kentucky and Virginia that lie at the foot of the Appalachian Mountains.

British thermal unit (Btu) — A measure of the amount of energy required to raise the temperature of one pound of water one degree Fahrenheit.

Daily sales volume — An operational estimate of the daily gas sales volume on a typical day (excluding curtailments).

Dekatherm (dth) — A measurement unit of heat energy equal to 1,000,000 British thermal units.

Development well — A well drilled into a known producing formation in a previously discovered area.

Exploratory well — A well drilled into a previously untested geologic prospect to determine the presence of gas or oil.

Farm tap — Natural gas supply service in which the customer is served directly from a well or a gathering pipeline.

Feet of Pay — Footage penetrated by the drill bit into the target formation.

Futures contract — An exchange-traded contract to buy or sell a standard quantity and quality of a commodity at a specified future date and price.

Gross — "Gross" natural gas and oil wells or “gross” acres equal the total number of wells or acres in which the Company has a working interest.

Hedging — The use of derivative commodity and interest rate instruments to reduce financial exposure to commodity price and interest rate volatility.

Horizontal drilling — Drilling that ultimately is horizontal or near horizontal to increase the length of the well bore penetrating the target formation.

NGL — or Natural Gas Liquids, those hydrocarbons in natural gas that are separated from the gas as liquids through the process of absorption, condensation, adsorption, or other methods in gas processing plants.  Natural gas liquids include primarily propane, butane, ethane and isobutane.

Net — "Net" gas and oil wells or "net" acres are determined by summing the fractional ownership working interests the Company has in gross wells or acres.


Net revenue interest — The interest retained by the Company in the revenues from a well or property after giving effect to all third-party royalty interests (equal to 100% minus all royalties on a well or property).

Proved reserves — Reserves that, based on geologic and engineering data, appear with reasonable certainty to be recoverable in the future under existing economic and operating conditions.

Proved developed reserves — Proved reserves which can be expected to be recovered through existing wells with existing equipment and operating methods.

Proved undeveloped reserves — Proved reserves that are expected to be recovered from new wells on undrilled proved acreage or from existing wells where a relatively major expenditure is required for completion.

Reservoir — A porous and permeable underground formation containing a natural accumulation of producible natural gas and/or oil that is confined by impermeable rock or water barriers and is separate from other reservoirs.

Royalty interest — The land owner’s share of oil or gas production typically 1/8, 1/6, or 1/4.

Transportation — Moving gas through pipelines on a contract basis for others.

Throughput — Total volumes of natural gas sold or transported by an entity.

Working gas — The volume of natural gas in the storage reservoir that can be extracted during the normal operation of the storage facility.

Working interest — An interest that gives the owner the right to drill, produce and conduct operating activities on a property and receive a share of any production.


Bbl= barrel
Btu= one British thermal unit
BBtu= billion British thermal units
Bcf= billion cubic feet
Bcfe= billion cubic feet of natural gas equivalents
Dtd= million British thermal units
MBbl= thousand barrels
Mcf= thousand cubic feet
Mcfe= thousand cubic feet of natural gas equivalents
Mgal= thousand gallons
MMBtu= million British thermal units
MMcf= million cubic feet
MMcfe= million cubic feet of natural gas equivalents
Tcfe= trillion cubic feet of natural gas equivalents

Media Relations

(For credentialed news media)

Mike Laffin
Vice President,
Tel. 412.395.2069

Investor Relations

Andrew Breese
Tel. 412.395.2555