Qualifying proppant performance prior to a frac job, or simply verifying proppant performance after a frac job, can add significant value to propped fracture stimulations. Through a blend of established practices and new technology, data can be generated that will give an engineer insight into how specific proppants are designed to perform. This is without running expensive and time consuming conductivity and permeability tests on every job.
A primary objective is to establish representative, reliable and reproducible data via a sample collected from a large mass. American Petroleum Institute (API) Recommended Practices (RP) identifies three primary tenets: 1) representative sampling from a flowing stream, 2) standardized testing with calibrated equipment, and 3) sample retention for follow-up evaluation. Application of these practices ensures that proppant test data is valid (e.g. representative, reliable, and reproducible). Yet, these practices alone typically quantify quality but do not qualify proppant performance.
Correlation of valid well-site proppant data with published information (literature, web-sites, or fracturing simulators) enables one to identify disparities. Any differences in part may be the result of mining anomalies, manufacturing defects, transportation abuse, and/or contamination. These can directly impact the delivered performance of your chosen proppant. Since proppant flow capacity or conductivity is a key measure of that performance, some empirical results have been assimilated for well-site and public data.
As a consumer, having information that describes the proppant at the well-site is important to deciding application and value. By compiling historical well-site proppant data one can set a minimum threshold of required properties or specification. This provides the opportunity to identify a greater range of proppants (e.g. substitutions) that meet reservoir, economic, and supply chain needs.
Lastly, new patent-pending technology is presented that enables well-site proppant sampling and evaluation before the fracturing treatment. Having pre-frac data gives one the opportunity to make any necessary changes in fracture design and implementation to get the most from available proppant. It also provides for a detailed inspection of the well-site delivered proppant supply. For instance, one can isolate and sample each pneumatic trailer, monitor associated pneumatic discharge pressures, provide representative split samples for fracturing fluid compatibility testing, etc.
Case histories, onshore and offshore, support “qualifying proppant performance”.