ResFracPro includes four types of boundary condition sequences that can be used to define well controls: injection sequence, production sequence, shut-in, and general. This document explains how each sequence type functions and when it should be used when setting up well schedules.
In most cases, injection sequences, production sequences, and shut-in periods should be used to define well controls. These sequence types are streamlined for standard workflows such as hydraulic fracturing, shut-ins, and production scheduling.
The injection sequence type assumes that a water-based frac fluid is being pumped. It includes options for specifying proppant input variables, fluid input variables, maximum injection pressure, and sequence truncation. The document provides guidance on selecting appropriate input types and verifying that injected volumes and pressures match job reports.
ResFrac allows both rate and pressure to be specified; however, these act as limits that work together. Once one limit is reached, the simulator adjusts the other to compensate. Care should be taken not to constrain both simultaneously.
Shut-in sequences (“NoFluidOrHeatFlow”) can be configured as either isolate wellbore or surface shut-in conditions. Measured depth boundary conditions are also discussed for cases where reporting or frac hit calibration requires specifying a depth location for the boundary.
Production sequences are defined by rate controls and allow specification of boundary condition changes over time. Guidance is provided on configuring production rate types, minimum pressure limits, and use of the production wizard to consolidate control records and minimize unnecessary boundary condition changes.
The “general” sequence type should be used for complex or unusual controls that cannot be handled by the other sequence types. For example, if injecting a hydrocarbon instead of a water-based frac fluid, a general constraint may be necessary.