shale hvhf technique & chemicals used
TRANSCRIPT
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Technical, Regulatory and Public Policy Issues
Hydrofracking Shale for New Energy
HVHF Technique and Chemicals Used
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• A combination of hydraulic pressure and granular “proppants” are used to open fractures and hold them open with sand grains or synthetic spheres. This is called hydrofracking.
• Producing natural gas from deep and tight formations is made possible or enhanced by increasing the effective porosity along the borehole gas producing zones.
• Fracking has been long used to improve the yield of oil, gas and water wells tapping consolidated (bedrock) formations. Before hydrofracking, explosives were often used to “frack” wells.
Hydrofracking
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• Fracking equipment typically operates up to 15,000 psi at flow rates up to 9.4 ft3/sec to inject a mixture of water, suspended proppant and additives to improve the fracking performance.
• Each drilling operation or “pad” must maintain a supply of water, proppant and additives in addition to the myriad drilling liquid storage and hydrofracking equipment.
Hydrofracking
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• Drill pad occupies approximately 5-6 acres that must be cleared and graded, access roads must be cut and trees / vegetation removed.
• Supplies of fresh water up to 4-6 mgd are required during drilling.
• Large volumes of process water and waste-water must be stored onsite and protected from spills.
• Fuel (mainly diesel) must be stored onsite to power drilling rigs and other equipment.
Drilling Operations
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• Runoff must be controlled so that precipitation, process water, waste-water and spills of chemicals and/or fuels do not leave the pad.
• Offsite receptors must be protected from air emissions, including odors and noise from drilling and support equipment/vehicles.
• Potential releases of natural gas could present immediate fire or explosion hazards in addition to adding greenhouse gas to the atmosphere.
Drilling Operations
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Aerial View of a Typical Drilling Pad
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Drill Rig Mast with Drill Pipe in Racks
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• Acids – hydrochloric acid (usually 28%-5
• Sodium chloride (salt)
• Polyacrylamide and other friction reducers
• Ethylene glycol
• Borate salts
• Sodium and potassium carbonates
• Glutaraldehyde
• Guar gum and other water-soluble gelling agents
• Citric acid – used in corrosion prevention
• Isopropanol – increases the viscosity of the fracture fluid
Frack Water Chemical Additives
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• Fracking water with chemical additives and proppants must be stored onsite and handled so as to prevent releases.
• The integrity of well casings and seals must be sufficient to prevent release of fracking fluid outside the desired depth.
• The location and depth of other formation penetrations (oil wells, gas wells, abandoned wells and test drilling sites) must be known so that cross-hole fluid leakage can be prevented.
• Flowback water must be controlled to prevent spills and discharges to the environment.
Control of Hydrofracking Fluids
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• Recycling of flowback water should be maximized if feasible to reduce water resource impacts.
• Flowback water onsite storage and treatment must meet applicable spill-prevention and containment BMPs.
Control of Hydrofracking Fluids
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Vertical Well Hydrofracking Schematic
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Horizontal Well Hydrofracking Schematic
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Geologic Cross-Section A Horizontal Well
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Well-head “Christmas Tree” and Piping
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Lined Pond, Frack Tanks, and Flare
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Filling Lined Drilling Pond
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Liner System
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• There is a two-fold demand for natural gas development in New York State: (1) a need for new, economical and clean(er) energy and (2) a desperate need for jobs, especially in economically depressed upstate.
• Much of the opposition is ideological and comes from outside the potential gas fields.
• Environmental disasters cited by opponents are virtually all unrelated to modern drilling and hydrofracking.
• Opponents are often funded by competing energy producers and a fictional motion picture depicting such a disaster was funded by a Canadian petroleum producer
Opposition to Gas Development