Guide to the different ways in which rocks are fractured in Oil and Gas field operations: a briefing paper

This note describes occasions when the reservoir rocks of oil and gas fields are fractured. These include: - Natural fractures, created over geologic time; - Fractures creased by Propellants; - Hydraulic fractures created by the pressure of water or some other fluid; - Propped fractures, in which fractures created hydraulically are held open by sand or a similar artificial material; - Acid fracturing; - Fractures associated with waterflooding; - Various other types of fracturing. A brief description of the fluids used in fracturing, and the factors controlling the orientation and size of fractures, are given. Typical shale gas treatments are described