SBIR-STTR Award

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

Multi-stage hydraulic fracturing and horizontal drilling technologies have been 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. GeoMechanics Technologies is developing an innovative technique that characterizes the fracture dimensions using both analytical and numerical simulation with inversion techniques from pulse testing to provide a clearer and accurate (about 66% more accurate) propagation of the fracture based on the pressure response. This novel technique would allow application to real world anisotropic reservoir conditions, such as dipping beds and varying lithology, providing a more accurate fracture analysis than current fracture diagnostic alternatives. During the Phase I study, we developed and validated the methodology to characterize a single hydraulic fracture using pulse testing. We also initiated a simple demonstration of multi-stage fracture study. The results from the multi-stage fracture characterization shows that the proposed methodology should be validated with field data since fracture characterization is highly sensitive to variations in reservoir properties and heterogeneous condition. For Phase II, GeoMechanics Technologies propose to expand on our Phase I efforts to provide a detailed study and an advanced technique of fracture characterization for multi-stage fractures. During Phase II, we will perform detailed numerical modeling studies with integrated geomechanics and flow models for multi-stage fracture system in horizontal wells for a range fracture geometry and formation characteristics. We will also demonstrate inversion technique to characterize the multi-stage fracture system and application with several real-world application examples. Actual field test will be performed during this Phase II. Finally, the fracture characterization techniques developed will be compared with actual field data to demonstrate the effectiveness of the techniques. Successful development and demonstration of this new technique will provide industry with a more cost-effect and improved technique to characterize single and multiple fractures in a wide range of geologic conditions. The technique is less costly than current fracture diagnostic alternatives, such as microseismic monitoring and downhole tilt meter monitoring. This information can lead to more effective production and more reliable evaluation of environmental risks, including enhanced protection of potential underground sources of drinking water.