Research on Mechanical Properties and Failure Mode of Conglomerate Based on Discrete Element Method

Conglomerate reservoir is an important part of unconventional oil and gas resources, which has great developmental potential. However, its sedimentary environment structural background are complex, cementation types, gravel volume fraction shape quite different, leads to strong heterogeneity. When developing a conglomerate reservoir, it extremely difficult drill because It obtain the mechanical properties laws through physical experiments, further restricts development process reservoirs. In order study failure law, three-dimensional numerical model built based on discrete element method, effects strength characteristics emphatically studied. The results show that elastic modulus uniaxial compressive decrease obviously with in strength. With increase strength, normal contact force increases significantly, distribution changes from cylinder sphere, heterogeneity decreases. There threshold value for influence conglomerate, when exceeded, no longer change obviously. content, decreases at first then increases, phenomenon penetrating gravels bypassing single diagonal crack into cross cracks; content jointly affect fracture morphology stress–strain relationship external macroscopic expression internal particles.