This is part 2 of a 3-part series based on a presentation by investigative journalist Andrew Nikiforuk to Squamish residents last year on LNG in BC.
What is shale gas?
Shale rocks are generally dense and black-coloured, formed from mud deposited at the bottom of past oceans, now solidified into rock. This mud is rich in un-decayed organic matter. When heated, the organic matter is transformed into oil and gas. Typically, this oil and gas is trapped between layers of shale and cannot be recovered through conventional drilling methods.
Fracking: what is it?
A well is sunk, which travels vertically through the overlying strata. When it reaches the shale layer, it becomes necessary to drill horizontally.
Modern wells are capable of drilling over 10km horizontally: such wells are called ‘extended reach laterals’. Once the horizontal well is drilled, it must be hydraulically stimulated, or as it has become known, “fracked”. The fractures themselves can extend well beyond the target because of the unpredictable nature of the shale formations. The horizontal well is “fracked” in portions, stage by stage every few hundred meters or so, meaning that a 2km lateral well might need 10 to 20 stages. For each stage, the targeted section of the well is sealed off and a chemical mixture is pumped down at high pressure.
The pressure of the water is sufficient to open up pre-existing fractures in the rock, and to create new ones. These fractures are important, because they provide a pathway for the gas to flow out of the shale rock and into the well. Once that is done, sand and gravel (proppant) are pushed into the fractures that have been created, literally ‘propping’ them open, ensuring that the gas can continue to flow.
The total fracking activity in the United States now uses about same energy as 11 nuclear power plants. Not to mention the water, sand and chemicals required.
Hydraulic fracturing was first done in the 1950s, but wells were sunk straight down; horizontal wells were not in use until recently.
In order to get the volume of Natural Gas needed to fill all these proposed LNG terminals, vast areas will need to be fracked. Essentially ¼ of the province will be fracked.
According to coal experts if five big LNG plants go ahead in BC then in order to keep those LNG terminals full it is going to require approximately 50,000 wells over the next 27 years. Or about 3,000 wells started each year.
Nine trillion cubic feet (tcf) per year of natural gas production and exports is planned by 2020. That is equivalent to 2 million barrels of oil per day, roughly the current level of production in Alberta’s oilsands. The current existing Canadian production is 5.3 tcf a year.
Pioneer of Fracking
United States is the pioneer of hydraulic fracturing (fracking) and they are only recovering 10 to 20% of the resource. The problems they have encountered are:
- pore spaces are 1000× smaller*
- can’t control the direction, width and size of fracks
- radioactive material
- hydrogen sulfide
- saline water
- high CO2 content
*Compared to sandstones and limestones, shales tend to have lower porosity, making it harder for the oil and gas to move about through the shale. This means that it is harder to extract gas from shale than from conventional reservoirs where the fluids can flow more freely.
What do you do with all that CO2? In BC we are now venting it out into the atmosphere. Australia is trying to bury it in the ground at great expense.
Shale gas wells have a rapid depletion rate of 80% whereas regular oil wells deplete at the rate of 20% to 30%.
Fracking operations are very complex. One problem in Northern BC is that companies are continually fracking into other companies’ fields. This is because of the horizontal wells.
A fracking project in Northeastern BC in the Horn River area had 16 wells sunk which required:
- 417 million gallons of water
- 78,400 tons of sand
- 8 million gallons of fracking chemicals
- 500 frack intervals
- 10,000 foot laterals
- 40,000 horsepower for fracking pumps
The fracking in northern BC uses 3× more water than other fracking sites. Every year fracking in BC requires the same volume of water used by the City of Calgary.
According to experts we don’t know where our aquifers are, how shallow they are, how big they are or how deep they are. We don’t know the water table elevation, we don’t know in which direction the ground water moves, we have no information.
The government of BC doesn’t even have a ground water monitoring program set up in the north where they are fracking now.
Last year the Minister of Natural Gas Rich Coleman tried to assure BC residents,
“the reality is we’ve been doing this for over 50 years, we’ve never had contamination from a drill, we’ve never had a drill stem leak or fail. We do it as well or better than anybody else in the world.”
Considering that there were no horizontal frack wells fifty years ago, isn’t that a misleading statement? There are only 6 monitoring wells for over 25,000 wells in the north. Who is tracking the contamination?
The more industry fracks shale formations the greater the risk to aquifers and ground water from methane leaks and contamination.
Methane gas gets into ground water. A study conducted by Duke University found that in 60 drinking water wells in Pennsylvania, 51 wells had 17 times higher methane and ethane content. This was because of leaky well casings, fracks had generated new fractures and or enlarged existing fracks which allowed the methane and ethane to escape into the water. They documented over 200 cases of ground water contamination.
Methane and CO2 venting:
On average 60% of aging wells leak methane gas. Industry calls this “gas migration”. It is a big problem, expensive to fix and difficult to completely stop.
Currently, there are 27,000 wells and 10% of them are leaking methane, and are super emitters. The fumes and emissions from these wells are incredible.
The problem is the fractures are uncontrollable. Fractures can spread out in all directions and this causes a waste of energy, a waste of fluids and chemicals, and wells end up fracturing into each other. Ultimately, water tables get contaminated and chemicals can pool on the ground.
So far, the BC government has yet to do a study on the impacts of fracking and LNG on the environment. This includes water, land, and air issues. Squamish residents have a right to be concerned.
Part 3 coming soon.
Original post in MID ISLAND NEWS (News Blog on mind vancouver island)