Subsurface Water and Fluid Flow in Sedimentary Basins

The pore spaces in sedimentary basins are mostly filled with water. Oil and gas are the exceptions and most of the information we have about fluid flow in sedimentary basins is derived from the composition of water and the pressure gradients in the water phase. It is therefore important to characterise and understand the variations in the composition of these waters. All the porewater may be referred to as subsurface water but the water that is analysed from exploration wells or is produced during oil production is usually called formation water or oil field brines.