Transcript Document

Hydraulic Fracturing
Best Management Practices
Environmentally Friendly Drilling Program
John Michael Fernandez
Matthew Gunter
Objectives of Presentation
• Introduce and describe hydraulic
fracturing
• Present environmental concerns
• Discuss best management practices
US Shale Plays
Major Shale Plays with
Hydraulic Fracturing
• Bakken
o North Dakota,
Montana, Canada
o Oil
• Barnett
o Texas (DFW Area)
o Natural Gas
• Eagle Ford
o South Texas
o Oil and Natural Gas
• Haynesville
o Texas, Louisiana
o Natural Gas
• Marcellus
o Pennsylvania, Ohio,
New York, West
Virginia
o Natural Gas
• Woodford
o Oklahoma
o Oil and Natural Gas
What is Hydraulic Fracturing?
• Hydraulic fracturing is a process used to
stimulate wells in tight, shale reservoirs.
• Uses water, sand and chemicals to
extend, prop open fractures to allow for
the flow of oil and natural gas.
Hydraulic Fracturing Process
• Drill the well
o
o
Some only vertical
Some have horizontal lateral
• Case and Cement possible hazard areas
o
o
Pressure zones
Ground Water Areas
• Perforate casing and cementing with Perforating
Gun
o
Begins fracture process in rock formation
• Pump fracturing fluid down hole
o
High pressured fluid extend fractures
• Production
Casing and Cementing
• Casing and cementing a wellbore is used
to:
o
o
Protect groundwater from contamination
Keep integrity of well-bore
• Casing is steel pipe that is designed to
handle:
o
o
over- or under-pressured zones and
high tensile stresses down hole
• Casing is cemented in place to safely
deliver hydrocarbons to the surface
Perforating the Formation
• Perforated using a “perf gun”
Perforating guns use explosive charges to
fracture:
o Casing
o Cementing
o Formation
o
Fracturing Fluid
• 98-99.5% Water and Sand
• The other 0.5-2%:
o
o
Additives that enhance fracturing
Many additives are used to protect casing,
cementing, and well integrity
• 3-7 million gallons of fluid used in typical
horizontal well
Proppant
• Sand pumped down hole is known as
proppant
o
Keeps fractures “propped” open
• Comes in three major forms
o
o
Untreated sand
Resin-coated Sand
 Coated for strength in harsh conditions
o
Ceramic
 Artificial Proppant, very strong at high pressures
 Said to be in shortage, more using resin-coated sand
• Selected based on strength needed and size
Chemical Additives
• Common Additives include:
Acids, Biocides, Gelling Agents, pH Adjusting
Agents, Corrosion Inhibitors, Iron Control, Clay
Stabilizer, Acid Inhibitor
o Other additives could be used depending on
well characteristics
o Additives considered harmful are often found
in household items
o
Hydraulic Fracturing Animation
Environmental Concerns
• Chemical concerns
o
o
Pumping chemicals near water table
Failure in pits and liners could leak chemicals
• High water usage
• Air Emissions from truck use
• Surface Area used
EPA Study
• Looking into groundwater protection
• Major areas of study include:
o
o
o
o
o
Water acquisition
Chemical Mixing
Well Injection
Flowback and Produced Water
Wastewater treatment/disposal
Water Table Safety – Fracture
Facts
• Fractures are necessary for hydrocarbons
to flow from the tight shale formations
• Fractures are typically thousands of feet
below water table
• They extend only hundreds of feet at most
in any given direction
Hydraulic Fracturing BMPs
• “Green Frac” Program Idea
o
Chesapeake Energy
• Refracturing wells
o
Restimulation via fracturing again
• Closed-loop Fracturing System
o
Chief Oil and Gas one of many users
• Pad Drilling
o
Drills multiple wells from same pad site
• Centralized Fracturing
o
Fracturing multiple wells from central pad
Green Frac Program
• Program instituted by Chesapeake Energy
o
October 2009
• Researching additives to:
o
o
o
Find which are unnecessary
Find which are necessary, but harmful
Find more environmentally friendly
replacements for harmful additives
• Specific findings are proprietary
information
Refracturing Wells
• Used to restimulate wells with production
slowed
• Reduces surface area taken by taking
away need for new well for oil and gas
• 85% of success found in 15% of total
wells drilled
o
Not universally successful
• When successful, greatly increases
production
Closed Loop Fracturing System
• Rather than using water only once and
putting in large pits, the frac fluid is
circulated and stored in large steel tanks
• Solids are removed from water using
mechanical and chemical methods
• Compared to older methods, CLF is
o
o
Environmentally friendly
Economically efficient
Environmentally Friendly CLF
• Takes away use of pits and liners
Pits and liners have been known to burst,
releasing chemicals onto surface
o Stores in large, sturdy steel tanks
o
• Uses much less water
o
o
Water is reused throughout fracturing process
Reduces water usage by as much as 80%
• Reduces truck traffic
Truck loads have been observed to reduce by up
to 75%
o Reduces air emissions and traffic congestion
o
Economically Efficient
• Water usage is reduced
• Truck mileage is also reduced
• Companies who have drilled similar wells
using CLF have saved about $10,000 in
overall expenses compared to
conventional drilling
Pad Drilling
• Drills multiple wells from single pad site
• Allows for centralized fracturing
o
Fracturing from single location for multiple
wells
• Reduces acreage necessary for wells
• Reduces truck traffic for making pad site
• Enhances closed loop systems
Centralized Fracturing
• Fracing multiple wells on a site from a single,
central pad
o
o
Fraced up to 140 wells from single site
Fraced up to 3 miles away
• Significantly reduces truck traffic and time
expended
Truck traffic was reduced by up to 30% for a single
well, up to 90% for the site as a whole
o Time was reduced by up to 80% to drill, complete
the well
o
• When used with closed loop and pad drilling,
saves even more truck traffic and water used
Past, Present, and Future Best
Management Practices
Conclusion
• Hydraulic fracturing is the future of the energy
industry
• There are environmental risks involved
• BMPs could be the answer to put unease at
rest
• When used in combination, BMPs can be
even more effective.
• Questions?