This paper demonstrates how multiple diagnostics, when applied effectively, can help accelerate the learning curve in an area and optimize field development. The operator can obtain exceptional knowledge concerning which technologies to choose when targeting specific issues for future developments.
The project involved a wine-rack of wells completed in Niobrara A, B, and C benches. Learning objectives for this project included the completions order, height growth in various benches, well spacing, well lateral landing, effect of varying treatment type and size, and cross-well communication. An extensive survey was performed of the various diagnostics available for fracture mapping, which included both near-wellbore (NWB) and far-field diagnostics. Keeping the primary learning objectives in mind, a project matrix was developed incorporating a variety of diagnostics focused on specific objectives. Inferred vs. direct measurement from diagnostics was considered. This process of "design of experiment" is discussed. The wells on the pad were all hydraulically fractured, and then the entire pad was moved to production phase post the hydraulic fracturing operations. Different fracturing fluids were also evaluated as part of the experiment.
The final project included far-field diagnostics, such as downhole microseismic, downhole fracture height, surface microdeformation, and interferometric synthetic aperture radar (inSAR), and NWB diagnostics, such as permanently installed fiber optics and radioactive (RA) tracers. The analysis was performed on individual diagnostics independently, and subsequently combined interpretations led to better subsurface understanding. Additionally, surface microdeformation data provided significant insight into the effects of "zipper fracturing" and how the treatment order of the wells was important for optimization.
With all data available, a fracture model history match on the permanent fiber optics well was constrained to the measured diagnostics. The final match between the aerial deformation from the surface tilt and calibrated fracture model was excellent and is discussed further.
Understanding the actual hydraulic fracture geometry is important in any unconventional field development because it dictates the stimulated reservoir and drainage patterns. While understanding the effects of various parameters (treatment type, fluid type, stage lengths, number of perforation clusters, etc.) on fracture geometry is essential, it is also important to understand the effect of multiple wellbores on a well pad.