The AAPG/Datapages Combined Publications Database
AAPG Bulletin
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AAPG Bulletin; Year: 2023; Issue: July DOI: 10.1306/10242221068
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Figure 14.
(A) Kerogen specks with lower ellipticity, α, take longer to initiate cracks because of the higher overpressure (ΔP ) required for crack initiation. The sudden vertical jump is caused by an abrupt stress release at the kerogen speck’s tips. The kinetics of the kerogen–oil conversion control the growth rates of cracks (the right-curving parts) most of the time. The shaded area represents the time interval required to create connected horizontal microcracks. The stress ratio for this simulation is σh /σv = 0.75. (B) The pressure change in kerogen specks during the kerogen–oil conversion. Point A represents the overpressure required to initiate a horizontal crack followed by a sudden drop because of the unstable crack growth. Then the pressure decreases slowly from point B to point C, eventually creating a connected horizontal microcrack network at point C. The stress ratio for this simulation is σh /σv = 0.75. σh = horizontal stress; σv = vertical stress; Rc /Rk = the ratio of the crack radius to the kerogen speck radius.
Figure 14.
(A) Kerogen specks with lower ellipticity, α, take longer to initiate cracks because of the higher overpressure (Δ