FracSolver is a state-of-the-art package for hydraulic fracturing simulation, including sophisticated hydraulic fracturing scenarios. FracSolver may be used both together with the existing Geonaft software modules and separately, relying on geomechanical and petrophysical calculations made in third party software.
FracSolver makes it possible to simulate a multi-stage hydraulic fracturing accounting for the interference of fracture stress fields. Changing of stress field of each fracture has an effect on opening, shape and curvature of all other fractures.
After modelling, the simulator determines the design of each fracture, calculates injection strategy, fracture geometry, its characteristics and conductivity.
FracSolver also makes it possible to evaluate technical and economic efficiency of hydraulic fracturing.
The concept is based on Planar 3D – the most precise (as of today) model for calculating hydraulic fractures with further correction taking into account external stresses. The model makes it possible to carry out exact fracture geometry calculation, factor in re-distribution of propping agent in the fracture, as well as propping agent bridging, and provide exact evaluation of conductivity of the reinforced fracture.
Hydraulic fracturing simulator is a complicated system aimed at solving the following tasks:
Well flow calculation (multiphase flow, measurement of flow with a propping agent, calculations for vertical, controlled directional and horizontal wells, interconnection of parameters at wellhead and bottomhole).
Calculation of fracture hydrodynamics (measurement of Newtonian or power rheology by two-dimensional approach, Carter model leak-off calculation, etc.)
Propping agent calculation (propping agent transfer, bridging, tip screen-out, etc.)
Geomechanical problem solving
Flow of hydraulic fracturing fluids with a propping agent inside the fracture is considered in the approximation of a lubricating layer.
Hydraulic fracturing is calculated with almost no simplification due to exact recording of the gap between propping agent and gel velocities.
The model also makes it possible to consider the following effects:
When modelling multi-stage hydraulic fracturing, one should take into account a number of features:
1. Multi-stage hydraulic fracturing is performed for controlled directional and horizontal wells
2. Each new fraction changes the stress field in the reservoir
3. Efficiency of fractures is highly dependent from the well position and reservoir conditions
4. The fractures interfere with each other during production
5. Inter-stage flushing should be modelled
FracSolver takes into account the above-mentioned peculiarities for modelling of multi-stage hydraulic fracturing and provides a final model with detail analytical data for each fracture.
In FracSolver software the user can set an optional injection strategy separately for each multi-stage hydraulic fracturing stage.
Injection strategy may be of a surface type (showing the procedure for well injection) or it may be a well bottom strategy, showing the procedure for fracture injection.
The results of calculation for each multi-stage hydraulic fracturing stage for a specific design may be displayed using a 2D graphic pad. A 2D analysis includes the following charts:
Geomechanical, petrophysical and geological data.
Fracture growth dynamics with time.
Fracture profile may be displayed at various moments together with animation.
The user may dynamically switch between various multi-stage hydraulic fracturing designs, as well as between various stages of a specific design.
Geonaft software allows to open any number of FracSolver modules and carry out the analysis of several hydraulic fracturing designs simultaneously.
FracSolver has advanced options allowing for 3D visualization of geological features, fractures, wells and other elements. A specific hydraulic fracturing design with the fractures coloured in accordance with the assigned properties may be displayed in a 3D sheet. There is an option for displaying fractures' opening at any time, as well as animation features.
The 3D sheet supports main visualization functions performed in geological modelling packages: displaying geological planes, faults, markers, targets, etc.
Report on multi-stage hydraulic fracturing design contains detail information on each stage. The report may be generated for each design, calculated by FracSolver and stored in Geonaft software project. The report may be edited by the user and any graphic material may be added.
The user may also generate optional report templates.