Understanding the Basics of Gas Exploration and Production Eric K. Albert, PhD And some of the career opportunities created by the industry

Our economy runs on energy! In 2009: Energy Information Administration

Natural Gas A non-renewable energy resource Used in a variety of ways: Energy Information Administration, 2005

As an energy source: Natural gas burns more cleanly than other fossil fuels BUT Still results in CO 2 emissions! And unburned natural gas (methane) is considered a greenhouse gas…

2008 US Natural Gas Total Production21,200 Billion Cubic Feet (BCF) Consumption23,200 BCF Imports3,984 BCF Exports1,006 BCF Wellhead price$7.96 / thousand cubic feet Avg. City Gate price$9.18 / thousand cubic feet Top US Gas Producing State7,760 BCF: Texas Energy Information Administration

How much energy? A BTU is the heat required to raise the temperature of one pound of water 1 degree Fahrenheit One cubic foot of natural gas (volume) contains about 1031 BTU One candy bar has about 1000 BTU! One cubic foot of gasoline contains about 961,000 BTU! [about 7.6 gallons]

Equivalent Energy Cost January 2011* Natural Gas price is $4.48 / Million BTU (MMBTU) compared to todays price of $3.19/gallon of gasoline the equivalent energy price of 1 gallon of gasoline is $25.23 MMBTU Put another way, at current prices, the same energy from Natural Gas is about 1/6 the cost! * NYMEX

How is Natural Gas formed? Trapped organic matter decomposing under pressure and heat… In time, depending on conditions, we get: Coal beds Oil fields Natural gas Think: even landfills are recovering methane from decomposing trash

How is it found? Geologists use a variety of means to locate possible sources… Knowing where it has been found already Historical geological setting Specific site location typically uses Seismic methods

Historical Oil and Gas Production USGS Oil: green Gas: red Oil & Gas: yellow

Main Phases of Gas Development Exploration Land identification for sites Location of deposits Environmental concerns Proving potential reserves Drilling Land leasing, right of ways Permits Pad development Roads and water infrastructure

Production Pipeline construction Monitoring and compliance Pumping and storage Well maintenance Post-production Capping / sealing wells Water quality monitoring Other compliance issues Site reclamation

EXPLORATION

Seismic Survey An array of geophones Data collection equipment A noise source – Vibrating trucks Explosives The reflected sound waves are collected and analyzed with computers to form structural images

Seismic Surveys

Resolution Resources

Marcellus Shale Gas deposit known since the 1930s Technology for recovery not available Price of gas too low for cost of drilling 6,000 -7,000 underground, maybe more PA gas wells: 35,000+ already in place Estimates 4,000 per year may be added

Traps Both of these types of rocks are impermeable, meaning that they do not allow liquids or gasses to move through them! Pore spaces filledPore spaces dont communicate

Geology.com

Drilling DTE Energy

Horizontal drilling is employed to connect to the largest reservoir space The drill string does not turn…but is steered to a horizontal line… This is accomplished through a steerable drill (Mud Motor) and a follow-behind probe (Measure While Drilling)

What does a borehole look like? Top View Side View Note: the casing system seals off higher elevations of rocks in the well so that only the production area is eventually connected.

Well Logging After the well is drilled, a log is made… Gamma ray = natural radiation in the rocks Neutron = higher reading means more hydrogen* This along with other data collected in the log helps to indentify if this will be a productive hole… Gamma Ray Neutron *Natural gas is a hydrocarbon!

Final Steps After the production area is reached: The casing is sealed to this area The production area casing is perforated by blasting The rocks surrounding the production area are fractured (hydraulic fracturing)

PRODUCTION

Deal or No Deal? Even so, after all this, the well might not be productive! Non-productive wells are plugged with cement and operations cease. Hydraulic Fracturing might be repeated in one well several times to attempt to increase pressure and recovery Higher pressure = higher flow rate = more valuable well

Transport A producing well is then connected to a pipeline for transport Also, to buffer the effects of seasonal demand, underground gas storage reservoirs are used. In PA there are at least 88 active reservoirs

Well Maintenance Well production is monitored both remotely and by on-site inspections Routine maintenance of the site is necessary to confirm safety and integrity of the well Water quality monitoring of nearby drinking water sources, as well as natural sites may be needed (looking for leakage of gas into sources…)

POSTPRODUCTION

Well Life A well might produce for 5, 10, even 20 years Production rates decline with time… Eventually the rate may be deemed too low to be useful, or non-economic Wells are disconnected, sealed (capped) with cement, and a surface vent pipe is installed.

Where are the jobs? Exploration Land identification for sites Surveyors, Civil engineers, etc. Location of deposits Geologists Environmental concerns Environmental techs, biologists, forest technology, chemists Proving potential reserves Geologists, Petroleum & NG Engineers Drilling Land leasing, right of ways Permits Pad development Roads and water infrastructure

Drilling Land leasing, right of ways Paralegals, title search, lawyers, land agents Permits Hydrologists, civil engineers, land planners Pad development Commercial drivers, riggers, drill operators, diesel power generation, construction, welding, electrical, heavy equipment Roads and water infrastructure Similar to Pad development

Production Pipeline construction Heavy equipment operators, diesel techs, welders, riggers, surveyors Monitoring and compliance Electronics, computer networking, communications / satellite techs, biologists, hydrologists, chemists Pumping and storage Well maintenance

Post-production Capping / sealing wells Construction, welders, general maintenance Water quality monitoring Other compliance issues Site reclamation Heavy equipment operators, forest / reclamation technology

Sam Kier, 1840s… Drake Well Museum How it all got started…

Questions?