Episodic, compression-driven fluid venting in layered sedimentary basins

Fluid venting phenomena are prevalent in sedimentary basins globally. Offshore, these localised fluid-expulsion events archived the geologic record by resulting pockmarks at sea-floor. Venting is widely interpreted to occur via hydraulic fracturing, which requires near-lithostatic pore pressures for initiation. One common driver extreme horizontal tectonic compression, pressurises entire column over a wide region. expulsion leads sudden, local relief of this pressure, then gradually recharges through continued leading episodic venting. Pressure recharge will also pressure diffusion from neighbouring regions that remain pressurised, but combined role compression and has not previously been considered. Here, we develop novel poroelastic model episodic, compression-driven We show together set period. derive simple analytical expression period, demonstrating can significantly reduce period associated with given rate compression. Our allows be inferred observations conclude major contributor fluid mudstone-dominated basins.