Shale Gas

Shale Gas is an unconventional type of natural gas; having the same composition as has a conventional one but produced from low permeability sediments, rich in organic matter. In gas shales they usually do not provide adequate pathways for sufficient flow of hydrocarbons into a well. Many still contain large volumes of gas but, because of their low permeability, they are rarely economic. It is certain that new ideas and new techniques will emerge in this field in the next future. Natural gas from shale is developed using horizontal drilling and hydraulic fracturing. Horizontal drilling; turning a vertical well onto a horizontal plane at a measured depth. This process of intersecting the reservoir horizontally allows the well to have much greater contact with the reservoir. Hydraulic fracturing pumps fluid and sand down a well at high pressure. The pressure causes the surrounding brittle rock to fracture. When the pumping pressure is relieved, the water disperses or flows back to the well and leaves a thin layer of sand to prop open the cracks. This layer acts as a conduit to allow the natural gas to escape from tight formations and flow to the well so that it can be recovered.