Fracture connections in ResFrac are governed by a small set of parameters that determine when and how hydraulic fractures interact with one another and with offset wells. This document describes the key parameters and how to use them to represent realistic fracture-to-fracture and fracture-to-wellbore connectivity.
In virgin reservoir, fractures connect when they come within the distance set by the ‘Fracture Collision Distance’ parameter. This single parameter is usually sufficient to capture frac-to-frac interaction in undepleted rock.
In depleted reservoirs, two parameters work together: ‘Depleted Fracture Collision Distance’ sets the distance, and ‘Fracture Collision Depleted Stress’ defines the stress threshold below which a region is treated as depleted. Together they let the model capture the larger effective collision footprint that develops after offset production.
Hydraulic connections to a cased offset wellbore are controlled by ‘Cased Well and Fracture Collision Distance,’ which sets how close a fracture must come to the wellbore to connect, while ‘Conductivity of the connect frac through ‘Cased well fracture collision distance’’ controls the conductivity of this behind-pipe connection. Use ‘Fracture Initiation Randomness Distance’ to control how far from the perforation cluster a fracture initiates, and use ‘Measured Depth Boundary Conditions’ to add volume to the system and tune the size of the resulting frac hit.