Modeling the Interaction Between Natural and Hydraulic Fractures Using 3D Finite-Element Analysis
| Autor: | Aditya Nikam, Obadare O. Awoleke, Mohabbat Ahmadi |
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| Rok vydání: | 2019 |
| Předmět: |
Fuel Technology
020401 chemical engineering Energy Engineering and Power Technology Geotechnical engineering 02 engineering and technology 0204 chemical engineering Natural fracture 010502 geochemistry & geophysics 01 natural sciences Finite element method Natural (archaeology) Geology 0105 earth and related environmental sciences |
| Zdroj: | SPE Production & Operations. 34:703-724 |
| ISSN: | 1930-1863 1930-1855 |
| DOI: | 10.2118/180364-pa |
| Popis: | Summary We built a 3D geomechanical model using commercially available finite–element–analysis (FEA) software to simulate a propagating hydraulic fracture (HF) and its interaction with a vertical natural fracture (NF) in a tight medium. These newly introduced elements have the ability to model the fluid continuity at an HF/NF intersection, the main area of concern. We observed that, for a high–stress–contrast scenario, the NF cohesive elements showed less damage when compared with the low–stress–contrast case. Also, for the scenario of high stress contrast with principal horizontal stresses reversed, the HF intersected, activated, and opened the NF. Increasing the injection rate resulted in a longer and wider HF but did not significantly affect the NF–activated length. Injection–fluid viscosity displayed an inverse relationship with the HF length and a proportional relationship with the HF opening or width. We observed that a weak NF plane temporarily restricts the HF propagation. On the other hand, a tougher NF, or an NF with properties similar to its surroundings, does not show this type of restriction. The NF activated length was found at its maximum in the case of a weaker NF and at nearly zero in the case of a stronger NF and an NF that has strength similar to its surroundings. In this study we present the results for a three–layered 3D geomechanical model with a single HF and NF orthogonally intersecting each other, using newly introduced cohesive elements for the first time in technical literature. We also conducted a detailed sensitivity analysis considering the effect of stress contrast, injection rate, injection–fluid viscosity, and NF properties on this HF/NF interaction. These results provide an idea of how the idealized resultant fracture geometry will change when several fracture/fracture treatment properties are varied. |
| Databáze: | OpenAIRE |
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