Investigation of the factors affecting the self‐propelled force in a multi‐orifice nozzle using a novel simulation method

Abstract

A multi‐orifice nozzle is the primary actuator of radial jet drilling for the stimulation of unconventional and low‐permeability reservoirs. This research developed a 3D flow field simulation model to investigate the self‐propelled force of a multi‐orifice nozzle based on ANSYS‐CFX. To evaluate the self‐propelled ability of the nozzle, investigation was performed on the effects of the angle, number, the diameter of the forward and backward orifices of the multi‐orifice nozzle, and the diameter of the micro‐hole in the radial well on its self‐propelled ability by sensitivity analysis. The results revealed that the self‐propelled force slightly increased with the angle of forward orifice increasing, and decreased with the angle of backward orifice increasing; and that the self‐propelled force had a tendency to decrease significantly with the number of forward orifices increasing, and increased slightly with the number of backward orifices increasing. The self‐propelled forces for different combinations of forward and backward orifices were obtained by the simulation method, which agreed well with those obtained by the calculation method, with an average accuracy of 95.82%. It was observed that the self‐propelled force increased substantially as the value of K (d2/d1) increased, but tended to slow down when the flow rate was within a certain range. Besides, with the increase in the diameter of the micro‐hole, the self‐propelled force reduced, and increased substantially as the inlet flow rate increased, but tended to slow down as the inlet flow rate further increased. Thus, to ensure the self‐propelled ability of the jet nozzle, a set of optimal structural parameters can be used to generate the target self‐propelled ability. The research improves the working performance of multi‐orifice nozzles and provides theoretical guidance for hydraulic radial jet drilling process.

Simulation on a new reverse circulation fishing tool: Design and evaluation of the salvage capacity and efficiency

“…The working conditions are set as follows. The wellbore outer diameter is 127 mm, the well depth is 3000 m, the bottom hole environmental pressure is P = 30 MPa, the drilling fluid density is 1.0 g/cm 3 , the relative environment temperature is 25°C, the inlet flow rate is Q = 240-600 L/min, the outlet static pressure is 0 MPa, and the wall of the annulus is free to slip.…”

“…There are many difficulties in returning debris, which can easily lead to vicious accidents such as sticking when fishing in various wells, including several stages of fracturing operation in shale gas well, complicating accident handling and increases production cost. [1][2][3][4] Using an effective drilling technology or tool to carry the debris from the drill pipe to better solve the stuck pipe accident caused by the impurity residue in the wellbore is a key problem that needs to be solved urgently.…”

Simulation and Experimental Study on Characteristics of Multiorifice Nozzle in Radial Jet Drilling

“…Chi et al calculated the maximum drillable length of jet nozzle by theoretical analysis and experiments [12]. Li and Zhang developed a 3D numerical model based on ANSYS-CFX to investigate the self-propelled ability of a multiorifice nozzle, remarkably the effects of the physical parameters of the multiorifice nozzle on its self-propelled ability by sensitivity analysis [13]. Wang et al conducted the experimental study of the NGH, and focusing on the effects of traverse jetting speed, jetting flow rate on rock breaking was studied [14].…”

Numerical analysis on fracture initiation from radial micro‐hole in anisotropy formation

“…9 Over the past few years, some researches and field applications (eg, the self-propulsion force of the hydraulic jet bit, the radial horizontal extension limit, the borehole trajectory measurement, the rock breaking capacity of the jet bit, the calculation of hydraulic parameters) have been conducted. [10][11][12][13] Obviously, the prediction of the fracture initiation in radial lateral boreholes should be studied in depth to more effectively control the variability of fractures.…”