Microseismic monitoring is the use of microseismic sensors to monitor the movement of the Earth’s crust.
Microseismic sensors detect seismic waves and convert them into electric signals that are sent to the computer. The computer analyzes the data to detect and identify microseismic events’ location, size, and frequency. As a result, the computer provides valuable information about the structures that are being monitored.
Reducing the cost of Microseismic Monitoring
The equipment used for microseismic monitoring is quite expensive, but the discussion of cost reduction has been floated because other funds need to be devoted to other areas.
It is a sore topic because using low-cost equipment does not seem ideal for getting the desired readings. A standard geophone is equipped to monitor weak local seismicity because the values are well below its operating frequency band.
The geophone is cheaper, making it ideal for reducing the costs of microseismic monitoring and increasing the observation points.
Maximize the Value of Microseismic Monitoring Data
To maximize the data, you have to combine and visualize the data through methods such as stratigraphy, lithology, existing wells, production data, and monitoring wells.
A set of geophones positioned in a shut-in offset mode is a way of maximizing the value of the data. The geophones can collect the data some distance away from the injection well. The geophones must be strategically placed on harder and more uniform rock to pick up more microseisms because sound travels further.
In enhanced hydrofracturing, placing the geophones near sandstone allows microseismic data to be collected from greater distances. Making random changes during the fracturing schedules influences fracture growth.
A better understanding of microseismic data and hydraulic fracture stimulation is important in maximizing the value of microseismic monitoring data. Once the value is maximized, reservoir models are developed to create precise readings of hydrocarbon production, adding more value to microseismic data.
Benefits of Microseismic Monitoring for Co2 Storage
Other geophysical techniques do not offer the same reliable data extracted from microseismic monitoring. Microseismic monitoring offers real-time data that helps operators safely store carbon.
Carbon needs to be stored at great depths to reduce the chances of carbon emissions, and that’s where microseismic monitoring applies. Microseismic data gives operators the safest location to store carbon and the safest points for carbon extraction injections.
Microseismic monitoring provides maximum information from a single component of geophone data. It is an adaptation of standard techniques making it more efficient in delivering the desired data.
Microseismic data monitors the movement of injected carbon, giving operators the location of the carbon each time there needs to be an injection.
Microseismic Monitoring: Measuring the Effectiveness of Reservoir Stimulation
Reservoir engineers use microseismic monitoring to help them plan and execute effective stimulations to maximize recovery.
Innovations in a surface array and geophone technologies have been at the forefront of helping experts filter noises from pumping and surface operations. The new technology has helped experts pinpoint microseismic events easily, which has helped reservoir engineers carve out grids that show fracture height, extent, and dip.
Reservoir stimulation has helped maximize microseismic monitoring data by delineating fracture networks. In DGI’s CoViz 4D, asset teams understand the quality and state of the reservoir. With CoViz 4D assets, the engineers can get an accurate picture of how the reservoir responded to recent fracturing strategies. It also helps the engineers to identify the ideal spacing for the additional wells.
Visualizing the data helps engineers plan future stimulation strategies and provides accurate assessments of its effectiveness.
In context, geological and reservoir factors need to be learned from previous stimulation activities.
CoViz 4D animates the data to help the reservoir engineers understand the effects of reservoir stimulation.
Selection and Processing of Parent Events
A parent event provides a template for the detection of other smaller events. These events are known as child events detected from the parent event’s waveform data.
A parent event is selected from a Matched Filtering Algorithm that analyses microseismic events during hydraulic fracturing.
The parent event has to be well-located to be obtained by conventional microseismic tools based on a high signal-to-noise ratio, using the parent events on the waveform data as the reference signals.
An automated process determines the child event by rotating the multicomponent waveforms into the coordinates of the parent event and maximizing the energy of the amplitude envelope around the parents’ hypocenter.
