Traditionally most natural gas has come from rock formations that, once drilled, allow the gas to flow freely. But supplies of this easy-to-access gas are declining. Many of the remaining vast gas resources lie trapped tightly in dense rock, inside pores up to 20,000 times narrower than a human hair.
Called tight and shale gas, these resources were previously considered too costly or difficult to access, yet the overall volume of available gas can be much higher than in conventional gas reservoirs. We use advanced technology to help gain access, contributing to global growth in natural gas production.
Shell has decades of production experience with tight gas – in the USA and Canada, the North Sea, and mainland Europe. Over time we have found ways to safely develop the fields and produce the gas with greater efficiency, lowering costs and limiting our environmental impact.
Producing tight and shale gas
At all our tight gas operations, we use a technique known as hydraulic fracturing to break open rock and release natural gas. This involves pumping fluids into the well bore at high pressure. The fluids comprise around 99% sand and water, with 1% chemicals added to help the gas flow more freely.
Fracturing typically takes place a kilometre or more (thousands of feet) below drinking water supplies. We insert concrete and steel barriers into the wells to prevent any drilling or fracturing fluids from entering into local water supplies.