Instrumented and Surface-Controllable Nonexplosive Mechanical Punching of Downhole Tubulars

Abstract

An instrumented, powered, and nonexplosive mechanical punching system with full surface control is presented to demonstrate the benefits and limitations of such systems versus traditional explosives and/or nonpowered mechanical punching systems. The paper will consider design criteria, performance, real-time outputs, flow areas, and operational risk factors when evaluating the different punching systems. The oil industry has run many forms of explosive and nonexplosive punching or perforating assemblies in wells over the years. As well design and complexity have changed over time, so has the need for punching and perforating methods. An instrumented and surface-controllable, nonexplosive mechanical puncher is the needed change in downhole punching and perforating methods for increasingly complex well designs. Such a system is seen as a safer, more reliable option than traditional methods, and it provides immediate feedback on the operation. Additionally, during punching operations, the system significantly reduces the risk of damaging control lines directly behind a tubular and eliminates the risk of damaging annular tubulars. Unique design factors and mechanisms were evaluated and characterized to develop an optimized instrumented and surface-controllable, nonexplosive mechanical puncher system. Puncher materials and geometries were evaluated for durability, forces required to penetrate a tubular, and flow areas generated. These punchers were characterized in multiple tubular sizes and grades to determine the relationships between tubular changes to changes in the same durability, forces, and flow areas. It was seen that different puncher types and tubulars have varying operational risks, durability, forces required to penetrate, and total flow areas generated. This information can be used to optimize a puncher to the operational objective. Additionally, through instrumentation, it was seen that there is repeatability in punches performed, and a successful "shot" and potential puncher wear can be determined. It was also seen that the system reduces risk in several areas. When compared to punching with explosives, there was no tubular swell at the perforations nor internal perforation burrs or damage. The system was punched directly into a downhole pressure gauge line behind the tubular with no damage observed to the external line after the punch hole was made. Finally, it was seen through surface control, powered options could be used to reduce any sticking risks. The novelty of the instrumented and surface-controllable, nonexplosive mechanical puncher system is in the engineering, design, and characterization of the system to provide an optimized, more reliable, and more efficient downhole punching system. In addition, there is value in knowing in real time the status of the operation, downhole diagnostics, and allowing of surface controls for risk management and additional contingencies.