Fracing in conventional natural gas reservoirs

Fracing under fire

The fracturing method (or fracing) used to extract shale gas has fallen into disrepute, largely due to claims that it introduces toxic chemicals below ground and therefore poses a risk to groundwater. The critics refer to the extraction of shale gas from shallow reservoirs in the U.S., which resulted in a negative impact on the environment and on groundwater supplies.

As a consequence of the emotionally charged public debate, conventional natural gas production in Germany is increasingly coming under fire as well. Through an open communication RWE Dea contributes towards greater objectivity in this discussion. This is achieved through a broadly-based programme of providing information and engaging in a public dialogue, for example at citizen information events and in discussions with other stakeholders in the media, politics and the general public.

Here are the most important answers to questions about the fracing process at RWE Dea

 

A safe and reliable method with a track record reaching back many years

Unlike the situation in the United States, where shale gas deposits are found at shallow depths, the so-called Rotliegend natural gas deposits operated by RWE Dea are located at depths of around five kilometres. In these conventional reservoirs, RWE Dea has been using the fracing method for many years without any negative impact whatsoever. The natural gas deposits have accumulated over millions of years deeply underground in sandstone formations located under a massive overburden of rock that is impermeable to both gas and fluids.

  • The vertical distance between the areas of fractured rock and the reservoirs of drinking water is over 4,000 metres.
  • The fact that gas deposits were able to form at a depth of five kilometres proves that the massive layers of rock above the deposits are absolutely impermeable.
  • Therefore, contact with groundwater is not possible.

  • In Germany, there has not been a single known instance where fracing has led to groundwater pollution or had any mechanical impact on the surface.

    Frac initiation point 

Non-toxic additives used exclusively

In the fracing process, RWE Dea uses only non-toxic prodcuts – most of which we encounter in our daily lives, and which pose no danger to the environment. To ensure that this is the case, the composition of the fracing fluid has been the subject of a great deal of research which has resulted in a constant process of further improvements. Right now RWE Dea is a participant in three separate research projects aimed at further optimising the composition of the fluid mixture. Moreover, the additives are also tested at RWE Dea's own laboratories and adapted to meet specific requirements.

Frac fluid mixture 

 

RWE Dea stance on the issue of “unconventional natural gas”

RWE Dea has been monitoring the debate on the issue of “unconventional natural gas” primarily from a research and development perspective, since the company first wants to gain a greater insight into its potential and feasibility. At present, shale gas projects have a low priority at RWE Dea. The focus remains on the production of natural gas and crude from conventional deposits. Nevertheless, shale gas is indeed a promising option for the future in certain countries with suspectedly large resources.


Prerequisites for projects involving exploration and production of shale gas

  • acceptance among the population
  • adherence to strictest international standards for environmental protection and safety

Before any shale gas project can get under way, it must therefore be ascertained that the available technology can meet these standards.