HYDRAULIC FRACTURING (Fracking) (2013)

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Hydraulic fracturing is commonly referred to as fracking or hydrofracking.

Controversy surrounds the increasing use of hydraulic fracturing to access resources of hydrocarbons. PSGR sets out what is involved in the technology and its variants and the potential for adverse effects on the human and physical environments.

Oil well is a general term applied to drilling a vertical or lateral bore into Earth's surface crust to locate and extract petroleum oil hydrocarbons , which usually include natural gas. Modern fracking is commonly done on lateral wells, several of which can be initiated from a single vertical bore.

When well drilling is used in conjunction with hydraulic fracturing, fractures can be enlarged or extended in rock strata that allow natural oil and gas resources to be extracted which are largely inaccessible to vertical well drilling alone. This significantly increases the efficiency of resource extraction.

The first identifiable frack job was done in about 1947. Since the late 1990s, improved fracking techniques have been used to establish commercially viable wells worldwide. The US Environmental Protection Agency (EPA) estimates there are now 35,000 wells fracked each year in the United States alone.

While a statistically small number of these wells have been proven to have resulted in health-threatening environmental damage, there is no excuse for ignoring them. Instead, Physicians and Scientists for Global Responsibility urges much greater attention be paid to their prevention at all levels of government, industry, and public investment. In doing so, the objective for New Zealand should be a long as opposed to short term, balanced, approach of esource development and environmental preservation. A necessary step in this direction is open recognition of such problems and the creation of the political will to face them.

1. Petroleum oil hydrocarbons - where are they found?

Rock fractures occur naturally and play a part in Earth’s dynamic processes. Fractures areformed, for example, by seismic and/or magma activity, thermal contraction, natural steam, and stress fields near the surface following volcanic eruptions. Understanding how these rock fractures work is essential for effective exploitation of natural resources such as groundwater, geothermal water, and petroleum oil hydrocarbons.

Some hydrocarbons are held in natural fractures, some in pore spaces, and some are adsorbed; that is, gathered as a gas or liquid or dissolved substance in a condensed layer on organic material.

Most often wells that are fracked are fracked for natural gas. Natural gas is typically found in porous sandstone, limestone and dolomite , and oil shale and coal beds.

Oil shale has insufficient permeability for traditional well drilling and has generally been seen as an unconventional source rock that is not accessible or commercially viable. With technology advances, oil shale is being targeted as accessible using hydraulic fracturing.

Oil shale basins are found on all continents with the possible exception of Antarctica. The depths of the basins vary. Some surface or shallow accessible oil shale is mined in situ or underground using the room-and-pillar method. Fracking is used where traditional methods are not suitable due to the depth of the shale. In the US, the Marcellus Shale lies approximately 1.8 kilometres deep, Eagle Ford 1.2 to 4.3 km and the Haynesville Shale 3 km. The Karoo Shale in South Africa is 2 to 4.5 kilometres deep.

World Shale Gas Resources: An Initial Assessment of 14 Regions Outside the United States
US Energy Information Administration (EIA)
www.eia.gov/analysis/studies/worldshalegas/

Gas Well Drilling and Development, Marcellus Shale
Susquehanna River Basin Commission, 2008 www.srbc.net/whatsnew/docs/Marcellusshale61208ppt.PDF; www.marcellus.psu.edu/resources/maps.php.

Characteristics of continental oil shale and oil shale resources in China
Petroleum and Basin Analysis Unit, Jilin University, China, 2008
www.ceri-mines.org/documents/28thsymposium/presentations08/PRES_11-3_Zhaojun-Liu.pdf.

1.2 Global reserves of recoverable shale gas and oil

According to the US Energy Information Administration, the largest reserves of recoverable shale gas are in China, followed by the United States. Argentina lies third at around 774 trillion cubic feet (tcf).

Australia has 396 tcf of technically recoverable shale gas resources. There is concern as to how it will affect aquifers on which Australia heavily relies, and a temporary moratorium is currently in place in eastern New South Wales State. A chart of ‘Proven reserves of natural gas’ shows New Zealand has 33,980,000,000 cubic metres (1,199,992,400,000ft³) as of 1 January 2012; 0.02% of the global total and low in terms of global reserves.

• International Energy Agency – multiple items on http://www.iea.org/1.3 Hydrocarbons in New Zealand

1.3 New Zealand Reserves

1.3.1 Taranaki Basin

Over 400 on- and off-shore exploration and production wells have been drilled in the Taranaki Basin, an area of about 330,000 km2. Currently, the Taranaki Basin reportedly supports 33 oil and/or gas wells between 1.5 to 4 kilometres deep, with further wells under development or on the drawing board for the near future. (See 6.)

Sediments in the Basin run from approximately 200 metres deep to more than 6000 metres / 6 kilometres deep. The hydrocarbon source rocks are Palaeocene and Cretaceous coal rocks and shales. Drilling targets are primarily sandstones. The Kapuni is as deep as 4000 metres / 4 kilometres; the generally shallower Moki, Mount Messenger and Urenui are at depths of 1,000 to 3,000 metres / 1 to 3 kilometres.

Fact File: Taranaki Basin
New Zealand Ministry of Economic Development

Taranaki’s wells produce 100% of New Zealand’s current hydrocarbon output, approximately 130,000 BOE/day (55,000 barrels/day of crude oil and 460 MMCF/day of natural gas). Reports claim the recent application of horizontal drilling in the region (fracking) is initially producing approximately 2.5 times the average rate for comparable vertical wells.

The rate of exploration is increasing. The New Zealand Energy Corporation’s Copper Moki-3 Well was drilled through the Urenui and Mount Messenger formations to the deeper Moki formation and has been flowing from natural reservoir pressure out of the Mt Messenger formation since 2 July 2012. It has a measured depth of 3,167 metres / 3.167 km and true vertical depth of 2,633 metres / 2.633 km. NZEC plans to drill up to 12 additional exploration wells in 2012.

1.3.2 East Coast Basin

There are around 300 oil or natural gas seeps identified in the region. During 2011 and 2012, an estimated 20 exploratory wells were to be drilled into unconventional shale formations.

The Kawakawa Anticline reportedly presents as much as 2,000 feet of fractured oil shale at relatively low depths. Late Cretaceous and Palaeocene marine shales are the primary source rocks, and investigations have revealed other source rock potential in, for example, sandstone, limestone, mudstones, marl, turbidite and terrigenous organic matter in the area.

Oil companies claim the East Coast Basin is an excellent geological environment for fractured shale exploration and compare it favourably to the Bakken Shale in Montana and North Dakota, and the Liassic Shale in France.

Fact File: East Coast Basin, Ministry of Economic Development

Assessment of Undiscovered Oil Resources in the Devonian-Mississippian Bakken Shale Formation, Williston Basin Province, Montana and North Dakota, 2008,

Shale Oil Potential of the Paris Basin, France
Adapted from oral presentation at AAPG International Conference and Exhibition, Milan, 23-26 October 2011, posted 9 January 2012

1.3.3 Western Southland Basin

The Western Southland region comprises numerous small basins, on- and off-shore. Drilling has taken place on-shore around the Waiau basin for coal-seam-gas and a recent significant discovery was reportedly found in the Goodwin-1 exploration well near Ohai.

The Western Southland Basin has thick successions, thick coals, oil shales and seeps. On-shore drilling around the Waiau Basin, Blackmount district, and Ohai has explored for coal-seam-gasxxiii which involves hydraulic fracturing.

Fact File: Western Southland Basins

1.3.4 Other Petroleum Basins in New Zealand

Petroleum oil hydrocarbon systems also exist in the following Basins: Reinga/Northland; Whanganui/King Country and Waikato; West Coast; Raukumara; Pegasus; Canterbury and Great South Basin.

The following discoveries have been made: Kawau gas-condensate; Galleon gas-condensate; Kora oil; Kauhauroa gas; Karewa gas.

Developments are taking place in the following Fields: Kapuni gas-condensate; Mangahewa gas-condensate; Maui gas-condensate; MacKee oil and gas; Maari-Manaia oil; Tawn gas-condensates; Pohokura gas-condensates; Tui Area oil.

NZ Petroleum Basins

Geochemical study of 10 oils from several New Zealand basins
Zink and Sykes 2010

Briefing - Out Of Our Depth: Deep-sea oil exploration in New Zealand, East Coast Basin November 2011

More information found here

2 Hydraulic Fracturing - fracking

Fracking is an induced pressurization process which opens up and enlarges fractures in targeted rock layers. The fractures allow natural resources to flow or migrate to well bores, in some circumstances these channels may also reach into aquifers and near surface waters and environments. While statistically small in number, such situations have cast doubt on the common use of fracking without significant assurances of its safety in these regards.

A fracked well bore could be about 130 mm to 900 mm in diameter, and can be drilled up to several kilometres deep. Once the required depth is reached, laterals are bored which on average extend horizontally up to one kilometre. In the Barnett Shale basin, Texas, laterals reach up to 1.5 kilometres, and in the Bakken Shale formation, North Dakota, 3 kilometres.

Opening fractures is generally accomplished by water injected under high pressure. The water contains proppants and chemicals, usually referred to as fracking fluid. Primarily, fracking fluid is forced into pre-existing fractures in the targeted rock. In some cases, explosives are used in the opening of a drill casing along the laterals. Fracking fluid, pumped into the bore, helps keep the fractures open.

Research on ‘super fracking’ is looking at how to create deeper fractures in rock layers to release more of a targeted resource. A method of fracking multiple laterals sequentially is patented (US7441604, issue date 28 October 2008). These laterals extend from a main vertical well penetrating the producing zone.

In 2009, there were reportedly over 493,000 active natural-gas wells across 31 states in the United States; about 90% having used fracking technology at some point in their development.

N.B: Fracking is also used to stimulate groundwater wells, to inject waste fluids deep underground, to extract heat for electricity from geothermal resources, to precondition rock for mining, and other applications.iii

Hydraulic Fracturing Research Study

Unconventional Gas Shales: Development, Technology, and Policy Issues
Anthony Andrews et al, Congressional Research Service, October 2009,

Search for fracking items on Scientific American

Natural Gas Extraction – Hydraulic Fracturing
US Environmental Protection Agency

3 The fracking process

Fracking is most often applied to a new well, but some wells are fracked repeatedly to extract as much oil or natural gas as possible. The process can include scouring with acid, injecting fracking fluids, and flushing with water after fracking has taken place.

Search US EPA: Hydraulic Fracturing Fluids, Chapter 4, EPA 816-R-04-003,

3.1 Acid

Acid is regularly flushed down a new well to dissolve rock debris and scour fractures prior to the injection of fracking fluid. Most commonly used is:

Hydrochloric acid: Hydrogen chloride is a common synonym for hydrochloric acid. Hydrochloric acid is a colourless, non-flammable aqueous solution or gas.

Toxicity: Hydrochloric acid is corrosive to the eyes, skin, and mucous membranes. Inhalation may cause coughing, inflammation and ulceration of the respiratory tract, chest pain, and pulmonary oedema. Exposure in the mouth may cause corrosion of the mucous membranes, oesophagus and stomach, with nausea, vomiting, and diarrhoea. Skin (dermal) contact may produce severe burns, ulceration, and scarring.

Other acids commonly used are:

Acetic Acid: Acetic acid (also known as ethanoic acid) is a colourless organic liquid compound. Undiluted it is called glacial acetic acid. It is a component of vinegar and under food additive code E260 is an acidity regulator and condiment; approved for usage in the EU, US, Australia and New Zealand. Concentrated acetic acid is corrosive; handling requiring specially produced resistant gloves. Concentrated, it becomes flammable if the ambient temperature exceeds 39 °C / 102 °F.

Toxicity: Dilute acetic acid, in the form of vinegar, is harmless. Concentrated acetic acid can cause skin burns, permanent eye damage, and irritation to the mucous membranes. Ingestion of stronger solutions can cause severe damage to the digestive system, and a potentially lethal change in the acidity of the blood.

Formic Acid: Formic acid, also known as methanoic acid, occurs naturally in bee venom and ant stings.

Toxicity: Formic acid has low toxicity and is used as a food additive. The principal danger is from skin or eye contact with concentrated liquid or vapours. Formic acid is readily metabolized and eliminated by the body; however, the formic acid and formaldehyde produced as metabolites of methanol are responsible for the optic nerve damage causing blindness seen in methanol poisoning. Chronic exposure to humans may cause kidney damage and the development of a skin allergy that manifests upon re-exposure to the chemical.

Muriatic acid: Muriatic acid is an aqueous solution of hydrogen chloride gas (HCI). It is completely solvent in aqueous solution. Muriatic acid gas is colourless to slightly yellow, corrosive, non-flammable, heavier than air. Exposed to air, muriatic acid fumes are dense white. When Muriatic acid is in contact with water, it forms hydrochloric acid. Mixed with oxidizing agents it produces chlorine gas which is toxic.

Toxicity: Muriatic acid is irritating and corrosive to living tissue. Exposure can cause breathing difficulties, a blue colour of the skin, accumulation of fluid in the lungs, swelling and spasms of the throat and suffocation, and can be fatal.

3.2. Fracking fluids

Acid scouring usually takes place prior to fracking. Fracking fluid is then injected at high pressure into the well bore. Generally, fracking fluid is primarily water, chemicals and a proppant (e.g. sand or ceramic particulates). It may contain compressed gases, such as nitrogen, carbon dioxide (CO2) and air, gels and foams, and radioactive components to allow tracing and measuring.

Reportedly, over 50 types of fluids can be used as fracking fluids. Fracking fluids can be oil-, methanol- or a combination of water and methanol-based.

Methanol Use in Hydraulic Fracturing Fluids, prepared for the Methanol Institute
http://methanol.org/Environment/Resources/Environment/Methanol-Fracking-Fluid-White-Paper-Aug-2011.aspx

As the fracking continues viscosity reducing agents such as oxidizers and enzyme breakers may also be added to deactivate the gelling agents and encourage flowback; fracking fluid returned to the surface.

Other fracking fluids include:

• Tallow-waste from beef processing, claimed as 100% non-toxic, water table friendly, http://www.prlog.org/11743014-eco-friendly-fracking-fluid-set-for-debut.html

• Liquefied petroleum gas (LPG), which carries sand or ceramic particles to prop open the fractures, but no chemicals. LPG is claimed as almost 100 percent recoverable. http://www.helioza.com/Directory/Business/Energy-and-Environment/Green-Natural-Gas-Fracking-1.php

The chemicals added vary with specific geological situations, to protect wells, and to ease the operation (see 3.2.2). They typically comprise up to around 2.5% of fracking fluids and the composition may change as the fracking operation proceeds.

Once the fracking is finished, a well is generally flushed with water under pressure, perhaps with a friction-reducing chemical added.

The volume of fracking fluid recovered varies. Recovered fluid may contain hydrocarbons, heavy metals, salts, and naturally occurring radioactive material (NORM) acquired during fracking.

Physicians and Scientists for Global Responsibility New Zealand Charitable Trust urge the application of the precautionary principle in regard to hydraulic fracturing. This would require the establishment of independent peer-reviewed published research into (A) the possible effects of hydraulic fracturing within the context of New Zealand's unique and unstable geological structures; (B) the immediate and long-term physical impacts of fracked wells on their immediate environs, including aquifers, and on the wider New Zealand environment; (C) hydraulic fracturing and its potential for adverse effects on the human environment; (D) the impacts on vital industries such as agriculture, tourism, and exports; (E) the impacts of limiting fracking on potential geothermal power developments and exports.

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