Microseismic Helps Us Track and Chart Fracture Initiation and Growth
Microseismic monitoring is an important tool that provides us with a better understanding of underground production processes, especially during hydraulic fracturing operations in our shale oil and gas reservoirs. Through the use of sensors called geophones, we can follow and analyze rock fracturing in real time to maximize the safety, effectiveness and efficiency of our operations.
Hydraulic fracturing is the technique of injecting fluid into cracks in underground rock formations to help release trapped oil and gas so it can more easily be extracted. It is commonly used to stimulate geologically complex and lower-quality shale oil and gas reservoirs.
Microseismic monitoring allows us to follow the process of hydraulic fracturing, which includes the initiation and growth of induced fractures, away from wellbores. We place a set of sensitive geophones both near the surface and deep into boreholes to create high resolution 3D images of preferred fracture directions, as well as their height and length.
This allows us to map the progress of the fractures and make adjustments, as necessary, to optimize our completion procedures, maximize well performance and protect the environment.
We can adjust our processes, including the rates and volumes of our pumps, the viscosity of the hydraulic fracturing fluids and the size or concentrations of the sand or other proppants we use, to create the most effective fractures and ensure the fractures we create stay close to our planned dimensions.
Microseismic monitoring helps us understand how the induced fractures grow and interact with pre-existing natural fractures in the subsurface. This is important, not only for a single well, but for the development of the field.
As new wells are added next to existing ones, we use microseismic monitoring to establish interaction with the previously depleted zone that surrounds the existing well. This helps us plan well spacing and helps us determine which specific fluids and proppants we use. On selected wells, we are able to watch hydraulic fracturing jobs in real-time, and thus provide immediate feedback to well site engineers about the ways the fractures are propagating and interacting with the subsurface.