The most effective fracture stimulation strategies begin by integrating, modeling, and visualizing relevant reservoir data—seismic, geomechanical, petrophysical, core analyses, well tests, and even historical production data—to obtain a detailed understanding of reservoir characteristics. Combined, these reservoir simulations and 3D geological models that depict faults, horizons, lithology; and proposed wellpaths provide a more detailed understanding of subsurface conditions. Visualized, these data facilitate detailed analysis of target thickness, formation permeability, stress distribution, fluid viscosity, and pressure, providing indispensable guidance to geologists and completion engineers as they develop fracture stimulation strategies to maximize recovery. Integrating, modeling, and visualizing a wide range of relevant data enables reservoir teams to make well-informed decisions regarding:
- reservoir fracture complexity
- number of frac stages
- coverage effectiveness of individual frac stages
- appropriate spacing between adjacent laterals
- proppant selection and pressure
Reservoir teams can also benefit from historical data regarding a nearby well or wells with similar geology. Stress analysis, permeability, fracture treatment, and subsequent production data can confirm or refute the efficacy of the completion strategy used for existing wells. That information can then be used as a reference to guide the stimulation strategy going forward.
With access to a wide range of data to advise the fracture stimulation strategy, engineers can then move forward in applying the chosen fracture treatment and acquiring data during the process to help ensure optimal execution.
Acquire Fracture Stimulation Data in Near-Real-Time
Data acquisition technologies have advanced to the point where reservoir engineers can monitor the progress of fracture stimulations in near-real-time. Seismic p-waves, collected via surface geophone arrays, are analyzed to understand fracture orientation and density. Additional data evaluating the frac stages can also be obtained through geophones placed downhole in offset wells. Together the data helps determine frac intensity, orientation, and density. Is it concentrated in the toe or heel or distributed evenly throughout the wellbore?
Microseismic activity resulting from the treatment can be detected, and with data integration and visualization software, mapped to depict their location, magnitude, and shear orientation. Microseismic data can continually be acquired and mapped to depict the development of the frac azimuth and dimensions.
In addition to microseismic data, near-real-time measurements of pump volume and pressure can be correlated with fracture development, allowing engineers to make pumping adjustments as needed.
Near-real time capture, integration, and visualization of a reservoir’s response to fracture stimulation allows engineers to closely monitor the effectiveness of the treatment.
Near-real time capture, integration, and visualization of a reservoir’s response to fracture stimulation allows engineers to closely monitor the effectiveness of the treatment. How do pump pressure and volume correlate with the extent and direction of fracture? Do dip and direction of fractures match expected in-situ stress analysis? Have any dead spots been detected? Which parameters have the most significant impact on fracture stimulation? Using this information, engineers can decide if modifications to volume, rate, or location of subsequent stages are required to optimize reservoir production.
Tools for Fracture Stimulation Analysis
Without sufficient software, analyzing the volume and variety of data acquired during a fracture treatment can be a challenging task. Integration of various data types, continuous updates as new data are acquired, and a 3D visualization environment that facilitates collaborative analysis by a reservoir team are requisite for accurate analysis.
CoViz 4D provides all the capabilities that reservoir engineers need for fracture stimulation analysis—from the initial assessment of subsurface conditions to help guide frac strategy, to the evaluation of the efficacy of previous frac treatments, to the near-real-time analysis of stimulations.
CoViz 4D enables reservoir teams to integrate seismic volumes and attributes, simulations, monitoring and microseismic data, production data, and other relevant reservoir data regardless of source of format. These data are then displayed and interpreted in a 3D environment as snapshots of reservoir conditions or as time-sequenced animations to further enhance the understanding of a reservoir’s response to fracture stimulations and production.
In particular, CoViz 4D excels in visualizing microseismic events (locations, extent, and frac stages) in context of geological and petrophysical data to clearly depict fracture stimulation progress and effectiveness. CoViz 4D can also incorporate surface and down-hole receiver locations, trajectories of treatment and monitoring wells, and perforations into the display to provide additional context for fracture stimulation analysis. As additional data are acquired during the frac process the information can be quickly and easily incorporated to visualize and evaluate the current status.
The Entire Fracture Stimulation Process Benefits From Accuracy
Every phase of unconventional well development benefits from as accurate as possible understanding of current reservoir conditions. Reservoir engineers can significantly enhance the probability of fracture stimulation success, from the initial analysis of reservoir characteristics to post-completion analysis of factors that influence production, using software that integrates and visualizes all relevant subsurface data.