000 02478nab a2200253 4500
005 20260520000316.0
008 260224s2013 xxu ing
041 _aInglés
245 0 0 _aFault transmissibility in clastic-argillaceous sequences controlled by clay smear evolution
260 _a
_b
_cmayo 2013
270 _a24/06/2013 ; 24/06/2013
300 _a26 p. ; 705-731
520 _aTranscripción del resumen del autor: The continuity of clay smears evolving in sealed direct shear experiments of initially intact sandstone-mudrock sequences was quantified to large displacements up to more than ten times the thickness of the sealing layer. The sample blocks consisted of a preconsolidated clay-rich seal layer, which was embedded and synthetically cemented in quartz sand. The mineralogy and mechanical properties of the clay layer and the reservoir sandstones were varied systematically to mimic a range of natural clastic rock sequences. The fluid-flow response across the fault zone was monitored continuously during deformation using a new type of direct shear cell. The displacement at which seals break down is closely linked to the amount of phyllosilicates in the seal layer. Contrary to expectations, softer seal layers do not seal better than stiff seal layers for a given clay content. In the testing range of normal effective stresses between 4 to 24 MPa (580–3481 psi) covering maximum burial depth conditions of approximately 800 m (2625 ft) to approximately 4 km (2 mi) (assuming normal fault tectonics), a systematic trend is also observed, indicating better smear continuity by increasing the effective normal stress. Predominantly brittle processes such as slicing and wear, and not ductile drag or plastic flow, appear to be responsible for the generation of clay smears. The test results offer the prospect of incorporating critical shale smear factors (i.e., normalized displacement at which seal breakdown occurs) into probabilistic fault seal algorithms that consider important properties that can be measured or estimated, namely, clay content and fault-normal effective stress.
581 _a5
773 0 _tAAPG Bulletin
_g97
942 _cARTICULO
100 1 _aGiger, Silvio B.
_953335
100 1 _aClennell, Michael B.
_953336
100 1 _aCiftci, N. Bozkurt
_953337
100 1 _aHarbers, Craig
_953338
100 1 _aClark, Peter
_953339
100 1 _aRicchetti, Mark
_953340
999 _c187781
_d187781