Last year, contributor Joe Levine wrote a letter to Commissioner Joe Martens of the NYS Department of Environmental Conservation regarding the failure of the draft SGEIS to address the issue of fluid and gas migration related to horizontal hydro-fracking. The letter attached numerous primary source documents, but itself stands as a valuable and concise reference summary of the scientific evidence related to this topic. We are publishing it here as a three-part series, of which this is the second part. For Part II, click here.

Marc Durand, geological engineering professor (Université du Québec à Montréal) whose discipline is rock mechanics and hydrogeology states (Shale G as Info March 12, 2011):

“Hydraulic fracturing artificially creates a network of interconnected fractures towards which the gas begins to migrate. The technique initiates the flow of gas in the deposit as happened in the classic natural gas deposits over hundreds of thousands of years, but the (fracking) technique cannot speed up the geologic process. The construction of a well and it’s fracturing are completed in a few weeks; the flow begins and continues on a geologic time scale. The amount of time before the well is closed (once the rate is no longer commercially viable) represents no more than an infinitesimal portion of the geologic time. Fracking gets out only 20 per cent of the gas (in a reservoir), a figure confirmed by Canada’s National Energy Board.

“After maybe eight years of production, the gas companies will seal – and forget – the wells, Durand said. That means that the remaining gas (80%), will continue to release itself from the shale (post fracking). The rock formations shattered by fracking will be thousands of times more permeable, allowing the remaining 80 per cent of shale gas and underground toxic water, 10 times more salty than sea water, to continue circulating, bubbling to the surface t ough disused (abandoned) gas wells. Over time, methane could leak into the groundwater and gas leaks could gush, uncontrolled, into the air. Because this happens deep below, it is not visible on the surface,” Durand wrote in a paper raising questions about shale gas.”

Paul Rubin of Hydro-Quest makes the same case in this report (Scope of EPA Study on Hydraulic Fracturing, August 10, 2010).

“Jacobi and Smith (2002) document the epicenters of three seismic events in Eastern Otsego County. These seismic events indicate that earth movement occurs from great depths along faults upwards to aquifers and potentially to exposure at the ground surface. The great lateral extent of these faults, and their visually observable connectivity with other faults, confirms that the process of hydraulic fracturing, which may interconnect naturally occurring faults and fractures, has a great a very real potential of causing contaminants to migrate to aquifers and surface water from localized zones across and beyond county and watershed boundaries. Fracking contaminants, once mobilized vertically along fault planes and fractures, especially under pressurized conditions, can reach freshwater aquifers. Even if all fracking fluids were comprised of non-toxic chemicals, the risk of interconnecting deep saline–bearing formations and/or radioactive fluids is not warranted. Any commingling of deep-seated waters, with or without hazardous fracking fluids is unacceptable. Documented gas excursions near existing gas fields demonstrate that vertical pathways are open. If gas can migrate to the surface it is highly likely that hydrocarbon and contaminant rich Light Non-Aqueous Phase Liquids ( NAPL’s) will also reach aquifers and surface water resources. These contaminants may then also migrate to down gradient wells, principal aquifers and waterways.” 1

So, what will be the legacy of shale gas hydraulic fracturing for NYS? Concerns regarding the aftermath are not addressed in the draft SGEIS except an oblivious assumption that the “sites” will be restored and look nice and grassy. That is the image that industry provides. Marc Durand provides the following analysis.

Marc Durand, from Shale Gas – A Business Plan Very Much in the Red

In 20 or 30 years how much will 20,000 depleted wells, which will simply have been concealed before being bequeathed to the geographic locale, cost us per year? There is total silence on this question, because the mining and oil sector has never been concerned for what happens to the drill holes afterwards. The industry has never allocated funds for that. The newest legislation requires only the rehabilitation of the site at the end of its exploitation. Companies must restore the surface of the site but there is almost nothing for what is underneath.

There are thousands of well sites at the end of their life span, hidden in the surface vegetation which have become all the more dangerous because their location has been forgotten. In the United States, there are more and more reports of victims of explosions from gas which resurfaces from old wells. In the majority of cases, it is old exploration wells dating from the beginning of the last century (Appalachia, Colorado). The problem will take on a whole new dimension shortly with the end of life of the gas wells situated in layers, which have undergone intense modification by hydraulic fracturing. The technique, newly applied on a large scale, will leave thousands of abandoned wells under inhabited zones, without anything being known of the impacts which will arise at the end of the work.

Let’s be clear about what we understand by the end of the life-span of a shale gas well. A working well has a life of 3-5 years. It is an optimal plan for extracting the gas as quickly as possible at the lowest cost. The output the fractured shale delivers is very high at first, then it diminishes logarithmically or exponentially. The wells are abandoned when the rate of gas is deemed unprofitable; at which point about 20% of the gas in place has been captured.

In classic gas reservoirs, up to 95% of the natural gas can be captured. For shales, recoveries are expected to be around 20% because of low permeabilities, despite high-density horizontal drilling and extensive hydraulic fracturing . (National Energy Board, A Primer for Understanding Canadian Shale Gas).

At the end of this period the extraction well is summarily transformed for another job or task whose sole purpose is to stop the flow of gas in the well. By means of blocking down hole plugs, cement plugs in the tubing, etc., the temporary extraction site must be turned into something permanent, the function of which is very different. In reality, practically nothing changes in the structure and composition of the well but the ad ition of a permanent plug. Whatever the design of the plug, the new work cannot have a drastically modified life-span. Nevertheless, these plugged wells must resist in perpetuity the pressure of the methane, which will continue to seep from the fractured shale. And let’s not forget that 80% of the gas remains in the shale at the end of extraction.

Underneath the inhabited plain, the Utica will have become an extremely permeable reservoir, still containing the left over methane after the skimming of the 20%. This enormous volume, 100 metres thick times 10,000 Km squared will be directly connected to the surface by 20,000 slowly corroding wells .The steel pipes and the sealing grout in an extremely saline environment will erode. This will possibly vary in speed from one well to another according to the quality of the sealing work done. The life duration of each of these wells, is the time before the deterioration is so advanced that major leaks force the authorities to intervene. From then on there will necessarily be a cost . This cost may appear very early in the process for certain wells, as has happened in Québec with some wells whose exploitation phase hasn’t even begun; but for now, the industry is still the owner of the wells and so pays the cost. This demonstrates though, that leaks occur even with brand new wells.

Figure 1 shows various routes the gas can take to reach the surface and drinking water wells. ( P ) The light blue letters ( A , B , C ) show the gas flow in the case where the drilling intersects a flaw or a long fracture. It is difficult to estimate in what proportion of wells this could occur because a detailed geological map is not readily available for the rock under the soft deposits of the St. Lawrence Valley. Figure 1: possible leaks for an extraction well – capped well.

Where there is the presence of such a fracture, the injected liquid opens this route and pushes very far ( A ) into the Lorraine strata. The flow path is opened permanently to continue into the sandstone and other more permeable layers.

Gas leaks show up in the artesian wells and the dwellings in proximity to the fault. Note that the fracturing fluid also penetrates a great deal further than the fault in the limestone ( A ) The Trenton is more permeable than shale and it contains very salty water. Thus a route is opened for saline contamination. Some analyses of fracking water indicate that this type of problem has already been encountered in the first wells.

Between the pipes and the drilled rock, and between the producing pipes and the protective sheath, the quality of the placement of the grout can leave spaces: annular fractures may also form during the intensive use of the wells. So that it is a possible origin of gas leaks coming from the wells themselves ( E and K ).

As well as these possibilities of leaks, at the end of the well’s life, probably between 2 and 5 decades after the end of operations, more generalized leaks will begin progressively, in growing proportion to the abandoned wells. The first reasons will be : 1) the disintegration of the steels and cements of the seal. 2) the pressure of the gas which builds slowly and surely on the capping. 3) the readjustment of the pressure (more precisely, the state of the constraints) in the fractured rock will slowly readjust, shearing off or deforming locally sections of the pipes.

The Utica strata tend to inflate when exposed; the same property in the depths will tend to flow and close up the opened fractures a bit over time. The fractured shale will thus tend to lose some of its permeability; but this will not be sufficient to return it to its initial impermeability. On the contrary, these micro ruptures will contribute to the liberation of yet more methane over time.

We are dealing here with structures which will disintegrate in extremely salty environments underground far from all possibility of inspection and maintenance, in rock transformed by the operations of hydraulic fracturing. The flow of fluids, saline water and methane will become modified. All the structures linking the surface of the transformed Utica will sooner or later attain an advanced degree of decomposition. The wells will reach a state where their function as sealing devices will no longer be operational. That means what exactly? Mega-problems at each of the wells, means of mitigation to be put in place, complex studies to be undertaken to try to find a solution, BAPE commissions for each site? (see my analysis of the Mercier case in my preceding text) There will be many of the 20,000, maybe between 250 and 500 new cases per decade in one generation. Billions to plan for in the budget of Québec.

If the heads of the wells are kept accessible for perpetuity, rather than restore the surface, one would have a less complex task, because one could sound the ground and know when catastrophe threatens. Yet no one anywhere is proposing that. It is said that the site mu st be restored at the conclusion of the extraction. All that means is burying and forgetting the problem until it hits us in the face. Finding a solution at that point will be an impossible task, as it is impossible to obliterate a well. The hole remains there, even if one tries to plug it with something else, that other material will never have the same properties as the shale that has been drilled and fractured. This Utica Shale has contained the gas for 400,000,000 years. All our technology, present and future will never manage to do that well. 2

Regulations cannot make fracking safe. No amount of regulation can control migration of fluids released by hydraulic fracturing. It’s actually based upon very simple physics.

1 RUBIN, PAUL A., Hydroquest. Comments on the EPA’s Proposed Study of Hydraulic Fracturing. August 10, 2010.

2 DURAND, MARC. Shale Gas—A Business Plan Very Much in the Red.