Impact of Pulse Plasma-Based Shockwave Technology on Sandstone Porosity and Pore Connectivity Using Ultrasonic Compressional Wave Velocity and Microtomography

The pulse plasma-based shockwave (PPBSW) technology has become very noticeable across many areas, such as the food, mining, and oil and gas industries. The present study deals with the impact of PPBSW on the pore network and connectivity of rock samples generated through the developed tool. It also provides detailed insight regarding the pore structure using micro-CT analysis. The study was performed on Indian sandstone and Berea sandstone samples under a set confining pressure using the suitable dimensions of the fabricated tool, enabling rapid deployment inside the well. This may assist in deciding the role of this technology in various oil field operations affecting hydrocarbon recovery. Core samples were characterized by mineral content, ultrasonic velocities, physical appearance, and microstructural evaluation before exposure to PPBSW. Core samples were subjected to varying shockwave pulses. Postexposure rock samples were analyzed by using ultrasonic measurements and microstructure evaluation. The results revealed that these shockwave pulses significantly impacted various parameters, such as porosity, ultrasonic velocities, physical appearance, and the microstructure of exposed core samples. The damage factor/coefficient of rocks was affected after the exposure. It was noticed that the impact increased as the number of pulses increased. The physical appearance of the field samples after the exposure revealed that, as the number of pulses increased, the chipping of the matrix, the creation of new voids, and the connectivity of pore space also increased, whereas micro-CT scans of the Berea sandstone samples revealed that porosity and connectivity between the pores were increased as the number of pulses was increased. One of the field samples was exposed to 100 pulses during which fractures were developed. In the presence of natural fractures in the rock, the creation of microfractures could easily connect to them. It may increase the permeability, eventually creating better fluid flow through porous layers and increasing hydrocarbon recovery. Thus, this technology is more suitable for creating voids and microfractures near the wellbore.