Role of Fluid Pressure in Mechanics of Overthrust Faulting

Hubbert, M. King; Rubey, William W.

doi:10.1130/0016-7606(1959)70[115:rofpim]2.0.co;2

Cited by 1,743 publications

(377 citation statements)

References 0 publications

Supporting

Mentioning

361

Contrasting

Unclassified

Order By: Relevance

“…(5) The induced earthquakes are localized to the region where the crust has been weakened due to fluid injection (Hubbert and Rubey, 1959). This last assumption seems plausible, but it is, nonetheless, difficult to prove that it always applies.…”

Section: Maximum Observed and Expected Seismic Magnitudementioning

confidence: 99%

“…Depending on rock properties, injection pressure, fluid volume and temperature, reservoir rocks can respond with tensile failure (hydraulic fractures; Hubbert and Willis, 1957), or with shear failure of preexisting joint sets (dilatant shear; Hubbert and Rubey, 1959). In the oil industry, the relationship between seismic events and hydraulic fractures has been studied extensively (Fix et al, 1989;Zhu et al, 1996;Dyer et al, 1999;Fischer et al, 2008).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Analysis of induced seismicity in geothermal reservoirs – An overview

et al. 2014

View full text Add to dashboard Cite

In this overview we report results of analysing induced seismicity in geothermal reservoirs in various tectonic settings within the framework of the European Geothermal Engineering Integrating Mitigation of Induced Seismicity in Reservoirs (GEISER) project. In the reconnaissance phase of a field, the subsurface fault mapping, in situ stress and the seismic network are of primary interest in order to help assess the geothermal resource. The hypocentres of the observed seismic events (seismic cloud) are dependent on the design of the installed network, the used velocity model and the applied location technique. During the stimulation phase, the attention is turned to reservoir hydraulics (e.g., fluid pressure, injection volume) and its relation to larger magnitude seismic events, their source characteristics and occurrence in space and time. A change in isotropic components of the full waveform moment tensor is observed for events close to the injection well (tensile character) as compared to events further away from the injection well (shear character). Tensile events coincide with high Gutenberg-Richter -values and low Brune stress drop values. The stress regime in the reservoir controls the direction of the fracture growth at depth, as indicated by the extent of the seismic cloud detected. Stress magnitudes are important in multiple stimulation of wells, where little or no seismicity is observed until the previous maximum stress level is exceeded (Kaiser Effect). Prior to drilling, obtaining a 3D -wave ( ) and -wave velocity ( ) model down to reservoir depth is recommended. In the stimulation phase, we recommend to monitor and to locate seismicity with high precision (decametre) in real-time and to perform local 4D tomography for velocity ratio ( / ). During exploitation, one should use observed and model induced seismicity to forward estimate seismic hazard so that field operators are in a position to adjust well hydraulics (rate and volume of the fluid injected) when induced events start to occur far away from the boundary of the seismic cloud.

show abstract

Section: Maximum Observed and Expected Seismic Magnitudementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Analysis of induced seismicity in geothermal reservoirs – An overview

et al. 2014

View full text Add to dashboard Cite

show abstract

“…High pore fluid pressures in rocks are known to lower the shearing resistance of rocks by decreasing the effective confining pressure [Hubbert and Rubey, 1959] and thus have a significant influence on the strength of the continental upper crust. A frictional strength minimum is, for example, inferred to occur along faults at the top of a suprahydrostatic fluid pressure regime that has developed beneath an impermeable layer [Sibson, 1990].…”

Section: Fluid Pressure Levels In Faults and Lithification Of Fault Rmentioning

confidence: 99%

“…A frictional strength minimum is, for example, inferred to occur along faults at the top of a suprahydrostatic fluid pressure regime that has developed beneath an impermeable layer [Sibson, 1990]. Although high permeability was shown to exist up to 9 km depth in basement rocks in the German continental deep drilling program (KTB) [ [Hubbert and Rubey, 1959 Sibson, 1986Sibson, , 1990Sibson, , 1992Cox, 1995]. In contrast to an inferred presence of unconsolidated gouge in creeping faults down to the base of the seismogenic regime [Scholz, 1989] …”

Section: Fluid Pressure Levels In Faults and Lithification Of Fault Rmentioning

confidence: 99%

Low frictional strength of upper crustal faults: A model

Streit¹

1997

J. Geophys. Res.

View full text Add to dashboard Cite

Abstract. Low frictional strength of faults is estimated based on existing models for earthquake recurrence, which account for compaction and hydrothermal lithification of fault rocks, as well as for the buildup of high fluid pressures in faults during interseismic periods. In areas of elevated heat flow and for a geothermal gradient of 30øC/km, fault compaction, lithification, and changes in fluid pressure gradient are inferred to occur at shallow crustal depth (3 to 7 km). Calculated shearing resistance of faults at seismogenic depths is compatible with shear stress drops ascribed to moderate and large earthquakes. The high frequency of microearthquakes, as well as the occurrence of some larger mainshock hypocenters at shallow crustal depth along several strands of the San Andreas Fault system are consistent with a predicted minimum of crustal strength at the top of a high fluid pressure regime. On the basis of field evidence from many exhumed faults for lithification of fault gouge and for faulting at near-lithostatic fluid pressures, a modified crustal strength profile is suggested to represent the strength of many active faults which involve hydrothermal fluid flow.

show abstract

“…Low sediment permeabilities limit the consolidation rate and cause fluid pressures in excess of hydrostatic [Neuzil, 1995;Hubbert and Rubey, 1959]. High fluid pressure in the drcollement implies that fluid should be forced out of the wedge along the pressure gradient leading to the hydrostatic ocean boundary at the seafloor.…”

Section: Introductionmentioning

confidence: 99%