Sealing of oil-gas reservoir caprock: Destruction of shale caprock by micro-fractures

The sealing ability of caprock is affected by many factors, such as cap thickness, displacement pressure, fracture development, and lithology caprock. Shale one the ideal materials for oil gas formation due to its low porosity permeability. Microfractures can destroy property shale When buried deep enough, will change from toughness brittleness. In general, greater brittleness shale, more developed fractures be. areas with high tectonic stress, anticline axis, syncline axis stratum dip end, strata stress concentrated, it easier generate fractures. state changes, new micro-cracks are formed or previously closed cracks re-opened, reducing pressure These micro-fractures interconnected form microleakage spaces, which reduces capacity