Study on Stimulation Mechanism and Parameter Optimization of Radial Water Jet Drilling Technique in Low Physical Property Sections of Petroleum Reservoirs

Abstract

Radial drilling-fracturing is an innovative fracturing technology that achieves superior stimulation effects. In order to study the permeability-increasing effect and main influencing factors of radial water jet drilling in the low physical section, this paper uses a fracking electrical simulation experiment, based on the principle of hydropower similarity, to simulate the reservoir conditions and well pattern in the low physical section and, at the same time, establishes the radial fracturing model of the low physical section reservoir, simulates the saturation field, pressure field, and production-change law under different drilling parameters, and studies different influencing factors. The experimental results show that when the number of drilling holes exceeds two, the effect of increasing production gradually becomes less significant as the number of drilling holes increases; Within the range of the angle between the two boreholes, the forward distance of the oil–water displacement front is the farthest and the sweep is relatively uniform. On both sides of the included angle, the forward distance of the oil–water displacement front edge is smaller than the forward distance of the displacement within the included angle range and it is clearly inclined towards the radial drilling with uneven spread. Radial drilling has an impact on the seepage field, causing changes in its streamline. The pressure inside the borehole is lower than the surrounding formation pressure and most of the flow lines change direction near the borehole location, causing deflection. As the borehole length increases, the oil-well production also increases. The optimal effect is for the borehole length to be 100 m. This study provides a reference for the on-site application of radial fracturing in low physical properties sections.