With regards to your question:
As suggested on my previous post, I’m in favour of placing an oscillation tool rather above the Drilling Jar, if possible*, to benefit from optimized weight transfer for both sliding steering of the directional BHAs AND preventing differential sticking in applications exposed to this stuck-pipe mode risks. But also, to help in effective Jarring in case of differential sticking while sliding, reducing flow-rate to the low range the oscillating tool can still propagate impulses.
Keeping the Drilling Jar in micro axial movement while
sliding warrants more effective chances operating it should differential sticking
occurs. Quick action from the driller is of essence in such cases.
Placement optimization of an oscillation tool in a string requires modelling of same accounting for the excitation force position, amplitude and frequency. On that basis, wave propagation of oscillations’ impulses up and down the string can be assessed and *best placement in a given string for a given application can be derived. Independent modelling is available today in that domain.
To answer your question: the impact forces of Jarring and associated shock-waves are an order or two of magnitude higher than the impulse forces of an axial oscillation tool. Example for 8’’ tools:
The Jar Blow is a product of the Energy Equation:
E = ½* (W/g)*V²
Where E is the energy available to perform the impact work (adequate BHA design) and accelerates the Jar Weight (W) to the Velocity (V) which is exponential in value.
In my opinion an Axial Oscillation Tool would not degrade Jarring efficiency in any applications.
Have run Ag-Itators both up in the string (above the Jars) and below the jars. Used them for different mechanisms and different reasons. Typically when using them for axial string movement to overcome the friction of the string when sliding, NOV has a certain "ideal" calculated placement. This is however also dependent on the MWD company, as the generated pulse could interfere with the MWD signal. Was on a job some years ago where Weatherford preferred the Ag-Itator 300m above their MWD system (worked well, by the way).
As said, also run them below the Jars, even below the MWD: the effect was that it certainly improved drilling performance, as it induces a kind of "jack-hammer" effect. Mind you, this can be quite fierce on the smaller tools, such as 4 3/4" motors, where we once had all ACME connections of the motor belled up by it. When running below the MWD, some systems could also have issues, due to the pressure pulse generated by the Ag-Itator which can spike once in a while.
Good tool though