Application of gas spark switch: A plasma-based improvement technology for unconventional reservoir

Abstract

Plasma pulse technology is one of the method to create fractures in the reservoir. This technology is inexpensive and environmentally friendly as compared to other reservoir improvement methods. In this paper, the application of gas spark switch as a pulse source in plasma pulse technology was studied. A set of plasma pulse device was developed, and the mechanism of each module was analyzed. The instantaneous breakdown process (Nanosecond level) of gas switch was described in detail by numerical simulation. The discharge experiments in the laboratory show that the equipment can achieve a stable discharge at high-frequency (25 min, 15–25 Hz) and low-frequency (40 min, 0–10 Hz). The field experiment of coal-bed methane (CBM) well was completed, the fractures-cavities have obvious development in north-south and 45° section direction, and extend down by 14.0 m (3.5 m before construction). The daily output of CBM well increases by about 11.78% after construction. The results show that the gas spark switch may have a potential application prospect in plasma pulse technology for unconventional reservoir improvement.