unit weight in torque_drag

[huangkai31]

I am reading the code of torque_drag_example, and would like to understand what's the unit of unit_weight.

In the BHA, the sample code:

 bha.add_section(
        od=(6.5 * ureg.inches).to('meters').m,
        id=(4 * ureg.inches).to('meters').m,
        length=(372 * ureg.ft).to('meters').m,
        unit_weight=(146.90 * ureg('lbs / ft').to('kg / meters')).m * 9.81,
        name='6 1/2" DC'
    )

and for Wellbore:

 wellbore.add_section(
        od=9+5/8, id=8.5,
        bottom=3688 * 0.7,
        unit_weight=(68 * ureg('lbs / ft').to('kg / meters')).m,
        coeff_friction_sliding=0.39,
        name='production 9 5/8" casing'
    )

so why BHA's unit_weight * 9.81 and not Wellbore?

[jonnymaserati]

Hi there @huangkai31! I'll take a closer look but I think you can ignore the unit_weight param for wellbore.

If I recall correctly, I've reused a class and probably forget to remove that param when I copied and pasted.

[jonnymaserati]

@huangkai31 I just tested and indeed that unit_weight param in wellbore.add_section can be commented out and it still works fine.

I've removed the line from the example code and it'll get pushed next time I push a new post. Thanks for the feedback!