Research and Field Test of Electrically Controlled Sidewall Deep Penetrating Perforating Technology

Traditional explosive perforation is subject to a short penetration distance and a compaction effect. Although the existing hydraulic perforating technology has remedied the deficiencies, it needs to cooperate with oil tubing or coiled tubing, with a long operation period and a high cost. Also, it is difficult to monitor the construction process directly and accurately only with surface pump pressure signals. With regard to this problem, research was performed on electrically controlled sidewall deep penetrating perforating technology (ECSDPPT). DC motors were selected to replace high-pressure water pumps as the energy source. Perforating tools were suspended by electric cables for transmission instead of oil tubing or coiled tubing, and the cables also transmitted electrical energy and delivered commands to control perforating operations. A real-time monitoring system was developed to monitor the drilling process into formations timely and accurately. As a result, an electrically controlled sidewall deep penetrating perforating system was built. Ground and field tests prove that the ECSDPPT enables the drilling into formations by over 2.00 m, forming a borehole with a diameter of 20.0–30.0 mm. The monitoring system can accurately calculate the actual perforating length in time by identifying and recording the electric pulse signals from a downhole Hall sensor during formation drilling. The research results demonstrate that the ECSDPPT relying on cable transmission is fast, efficient and low-cost. It overcomes the shortcomings of conventional explosive perforation, providing a new method for connecting and reforming near wellbore formations. In addition, the monitoring system can record the drilling length and other parameters in real time during construction, effectively solving the failure of the existing hydraulic perforating technology in monitoring the working process.