SHALE GAS What is that ?

The Revolution of Resources and Efficiency

The growth of our Company over the last few centuries has been supported by the availability of easy-to-find resources in large quantities. We had to nourish, heat up, build our inventions and machines, and grow a growing and demanding population. Beyond the DISTRIBUTION of this abundant mess, which is also a matter of paramount importance, we can say that it could have grown substantially without limitation.

Towards the end of the last century, however, the first concerns about the actual sustainability of this growth rate began to emerge, first on the front of the availability of the main sources of energy we were using and subsequently with reference to (almost) all other raw materials, agricultural and water products.

We began to question how to use new sources and resources, how to preserve and preserve existing ones, and the so-called ' efficiency revolution ' has begun. The themes of sustainability characterize the ethical nucleus, but it concerns the use of the territory and the space in which we live, that of resources, energy, and water.

In the particular case of traditional energy sources, the increase in demand and their limited availability has generated a significant increase in price, with two effects: an impetus to efficiency, and we talked about it, and an impetus to look for new fields or new sources.

The last twenty years have seen enormous development of research and extraction techniques. New deposits have been found but have also been attempted to extract oil and gas from where, to date, it had not been possible. In these pages we will concentrate on unconventional search techniques, so defined to distinguish them from those that are (and continue to be) used in extraction.

We will mainly talk about unconventional gas , but we must remember that there is also an oil unconventional (non-conventional oil).

Shale gas

The impetuous development of unconventional gas has been possible thanks to a very special technological evolution in extraction techniques.

The fracking ( hydraulic fracking, or simply fracking) has begun to spread in the fifties of the last century. In practice, a drilling device is combined with a pressurized water injection device that causes microfracturing in the rock or very well-sanded sand banks through which the gas content ( METHANE ) or oil is released and re-emerges with the reflux of the " injected water.

It is not just water: in relation to the different geological features of the GIACIMENTO and the nature of the substance to be extracted, specific additives are added to the know-how of the extractor. The water that flows is rich (in addition to oil and gas), also of contents derived from the microfractured geological matrix, salt and additives just mentioned.

The great technological innovation of the last ten to fifteen years has been sub-horizontal directional perforation. Born for microtunneling, the construction of cable or polyphony wires for technological use, was soon perfected to adapt it to the mining industry.

Gas-rich shingles often have a limited thickness and a very large surface area, and suborange drilling allows them to be followed for lengthwise development to allow the extraction of important quantities of gas and oil. This is the case of gas from, or shale gas , or shale gas , just because of the spontaneous nature of the geological formations that hold it imprisoned. Gas can also be contained in very compact sand deposits (it is referred to as tigh sand gas) or in the body of coal deposits (it is referred to as coal seam methane or coalbed methane). The image makes the idea of ​​the complex variety of deposits that today is made possible to exploit.

Thanks to this evolution, gas extraction with unconventional systems becomes possible at competitive prices compared to the current high price of traditional resources (whose growth was, as we have seen, determined by limited availability and high demand).

Think of the formation known as  "Marcellus Shale" , one of the largest non-CONVENTION GAS fields in the world that covers six US states in the northeast and therefore needs more drilling to gain access to gas. According to the US Department of Energy, a 2009 report on shale gas development estimates that 3,800,000 gallons (15,200,000 liters) of water are needed for fracturing in a single well, with an additional 80,000 gallons for drilling.

The next figure outlines all the extraction process with the new techniques.

 The effects on the production equilibrium

We look at the map. The DISTRIBUTION of the estimated (and presumed) deposits varies greatly with extraction geography than that used by conventional gas and oil. Countries such as the USA, Argentina, Poland, and South Africa could soon become exporters of fossil sources rather than importers, making probably the same fossilized and least expensive fossil sources.

The same problem, which seemed so languid towards the end of the last century, that the fact that it was to reach the peak in oil production, assumes a relative importance. So how could the role and weight of countries that are currently producing gas and oil, which is essentially concentrated in the Middle East, change, a whole season of balance on the planet's layout would seem to come to the front.

In terms of relative importance of shale gas production compared to traditional sources, the most reliable estimates and ratings were made in the United States where extraction has begun for some time and exploration has provided the POTENTIAL of production. The picture below shows very well the expectations: shale gas is starting to become the first energy source for the US. Similar scenarios have been developed for Australia while the European country ahead in this regard is the United Kingdom.

What are the critical aspects

If the benefits of greater availability of energy sources are quite obvious, it is also worth discussing the critical aspects that arise from the exploitation of these particular fields.

The most delicate aspects are:

• Hydraulic fracturing, and in particular water injecting into the subsoil, can lead to interference with the fence from which communities draw for domestic, irrigation or industrial uses.
• 'Chasing' the deposits throughout their extension may have a detrimental effect on the environment and the ecosystems involved.
• A negligible amount of gas is lost in the atmosphere, and METHANE is 24 times more effective than CO2 in generating the GREEN EFFECT .
• Water is not an inexhaustible resource, and only 2.5% of the existing water is non-salty water, and extraction with this mode requires a lot of it and produces a lot of pollution.

Each point would deserve a long discussion, but we will review them briefly, leaving some more detail in the water theme.

The exploitation of a well of this kind reaches depths of hundreds of meters, normally well below the superficial foothills that feed our aqueducts. However, the regulations have become very sensitive in this respect and require accurate hydrogeological and basin analysis studies before authorizing the exploitation of deposits, and in particular those involving the use of fracking techniques.

Similarly, in-depth environmental impact studies and attentive assessments of the effects on local ecosystems have become an inevitable prerequisite for extractive activities. Especially as regards the shale gas, which, as seen from the map above, is present in very large and often significantly inhabited areas, when not even of naturalistic value.

The issue of SERRA EFFECT is responding not only to the extraction of shale gas but also conventional gas. Mining techniques, and especially transport, have been made more accurate and sophisticated, although improvements continue to be made and are aimed at significantly reducing the problem.

Water and gas: unconventional resources?

The future of oil and gas is intimately tied to that of water. It is around this precious resource that plays the development of the industry and, above all, of new sources of energy such as GAS NON CONVENTIONAL whose geological peculiarities make indispensable a great water expense in drilling and extraction.

While we are witnessing the increasingly apparent impact of climate change on production cycles and, on the other, the growing scarcity of water resources, we are experiencing an incredibly energetic era, where hope lies in new sources of energy. We think of the discovery of large  shale gas fields in countries such as UK, Poland and Ukraine: global attention towards this source of energy is very high today. 

The issues related to the availability and treatment of production waters are a topic that has affected the industry since the times of the West's Gold Mines and, incidentally, it is precisely when it comes to legislation on the subject. So much so that the evolution of environmental legislation in the oil and gas sector leads some US States to issue mining and production permits only in areas where water availability or supply is proven, provided that it does not escape other priority areas such as the residential and agricultural sectors. No water, no oil, then.

However, although oil extraction and production continue to pose challenges in terms of water use (mainly by injection) and reclamation (separation of production water from hydrocarbons, recovery of crude oil from "return water" ", Water purification from saline concentration, re-use of water in the extraction process, etc.), water issues related to the extraction of non-CONVENTION GAS are obviously more complex.

In addition, while always using fracking, the quantity and quality of production water associated with conventional gases may change depending on the type of gas. In the case of coal seam gas, for example, the amount of production water is generally higher than that associated with shale gas; Their saline concentration is also higher and less stable, so treatment solutions are more complex than gas shale.