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| Titel |
Reliability of poroelastic equation in determination of minimum horizontal stress in sedimentary basins: implication of tectonic strain |
| VerfasserIn |
Uy Vo, Chandong Chang |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250142584
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| Publikation (Nr.) |
 EGU/EGU2017-6222.pdf |
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| Zusammenfassung |
| Minimum horizontal stress (Shmin) magnitude, normally one of the three principal stresses,
provides vital information in various stages of petroleum development such as hydraulic
fracture design, wellbore stability analysis, and sand production prediction. Mini-frac or
leak-off tests (LOT) are considered to be the technique used to measure Shmin magnitudes
directly in the formation. Still, other than being time-consuming and costly, LOT does not
give a continuous Shminprofile. A conventional alternative is to use a linear poroelasticity
equation derived based on the assumption of uniaxially strained basins, which provides
minimum horizontal stress magnitude (Shmin) as a function of vertical stress, pore
pressure and Poisson’s ratio (ν). In this study, we inspect the reliability of poroelastic
equation-based calculation by comparing measured data of Shmin, pore pressure with
log-based minimum horizontal stress magnitude in 6 major sedimentary basins
worldwide. For calculation of Shmin via the equation, we assume ν of 0.25 and
Biot’s constant of unity. The comparison shows that the predicted Shmin values
generally underestimate the measured values by a range between 4% and as high as
29% depending on the regions. The wide variation of horizontal stress may imply
unpredictable complications in the stress states in the sedimentary basins. Besides,
we also collect the data of maximum horizontal stress magnitudes and Young’s
modulus to estimate local tectonic strains, which are responsible for additional
stresses over the induced horizontal stresses. The result reveals that the tectonic strain
magnitudes are not consistent with the difference between measured and calculated values
in minimum horizontal stress. Our results suggest that rock mechanical property
such as Young’s modulus is a more dominant factor that controls tectonic stress. |
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