Development and Testing of Advanced Inter-well and Inter-Stage Pressure Pulse Analysis for Fracture Diagnostics

Multi-stage hydraulic fracturing and horizontal drilling technologies have been the primary contributors to the very substantial increase in natural gas and oil production from shale and tight sand formations in the US over recent years. With increased application of fracturing in horizontal wells, it is critical to better characterize and monitor “where the fractures go” both to optimize production and at the same time to ensure fracture containment in the target interval to avoid inadvertent impact to potable water supplies or out of zone methane migration. The objective of this research is to develop and demonstrate with field data a more accurate and cost-effective technique to estimate fracture height, length, and orientation than currently available technology. We propose to develop advanced techniques to analyze pressure pulses from horizontal well fracture operations recorded at offset wells or at other perforation/stage locations within the same well to monitor and characterize hydraulic fractures. During Phase I, we will expand and improve the theoretical and analytical solutions for pressure pulse analysis and fracture characterization of single vertical well fractures. These will be expanded to evaluate single and multi-stage fractures from horizontal wells, with pressure measured at either offset well or at other stage locations within the same horizontal well. The analytical solutions, which are generally assuming a simple and uniform reservoir geometry, and material property, will be complimented with advanced coupled fluid flow and geomechanical numerical models. This allows real world application of the technique to the dipping and heterogeneous reservoir conditions. Finally, the techniques developed will be compared and calibrated against actual field data from fracture operations, in which pressure sensors have been placed at multiple offset well locations. Successful development and demonstration of this new technical approach for fracture characterization will provide industry with a more cost-effect and improved technique to monitor and diagnose fractures from horizontal wells, providing a tool for more secure environmental protection and enhanced production of oil and gas. Key Words: Hydraulic fractures, pressure pulse analysis, horizontal drilling, fracture characterization