Hydraulic properties of 3D crossed rock fractures by considering anisotropic aperture distributions
Journal Title: Advances in Geo-Energy Research - Year 2018, Vol 2, Issue 2
Abstract
This study presents a numerical study on the geometrical and hydraulic properties of a three-dimensional intersected fracture model that is a fundamental element involved in complex fracture networks. A series of rough fracture surfaces were generated using the modified successive random additions (SRA) algorithm. Different shear displacements were applied to the fracture to obtain the anisotropic aperture fields that will be further assigned to the two fractures in the intersected fracture model. The flow was calculated using the Reynolds equation with the continuity conditions addressed at intersection part between the two fracture planes. The evolutions of the aperture distributions, flow channels and equivalent permeability were estimated. The simulation results reveal that as the shear displacement and joint roughness coefficient (JRC) increase, the aperture increases anisotropically, which causes significant fluid flow channeling effects. The main flow channels change from being concentrated in one fracture to the other fracture during the shear, accompanied by the change of the flow rate ratios between two flow planes at the inlet/outlet boundary. During the shear the average contact area accounts for approximately 4% to 15% of the fracture planes, and the actual calculated flow area is about 35% to 42% of the fracture planes, which is smaller than the noncontact area. As the shear displacement and JRC increase, the equivalent permeability of the intersected fracture increases. Therefore, the channeling flow should be considered to interpret the fluid flow through the rough fractures even in the simplest fracture networks.
Authors and Affiliations
Richeng Liu, Yujing Jiang, Na Huang, Satoshi Sugimoto
Controlling factors and physical property cutoffs of the tight reservoir in the Liuhe Basin
Tight gas sandstone reservoirs of the Lower Cretaceous Xiahuapidianzi Formation are the main exploration target in the Liuhe Basin in China. Petrology characteristics, reservoir space (pore space), controlling factors an...
Impact of fracturing liquid absorption on the production and water-block unlocking for shale gas reservoir
A large amount of liquid is pumped into the shale gas reservoir during hydraulic fracturing, and the fluid flowback ratio is usually low. However, field experience showed that the liquids did not cause severe damage to s...
Impact of four different CO2 injection schemes on extent of reservoir pressure and saturation
This study investigates how four different injection schemes, (i. constant rate, ii. stepwise increasing rate, iii. stepwise decreasing rate, and iv. cyclic rate), constrained by the cumulative amount of CO2 injected, af...
Well pattern optimization based on StoSAG algorithm
The well pattern optimization in the oilfield is challenging and intricate work due to the heterogeneity of the permeability and viscosity. Traditionally, the well pattern optimization is conducted by comparing the resul...
An analysis of the key safety technologies for natural gas hydrate exploitation
Natural Gas Hydrate (NGH) is a high combustion efficiency clean energy and its reserve is twice as that of natural gas and petroleum, so NGH is the potential resource which could overcome the increasing energy assumption...