LWD interpretation - Resistivity

Resistivity question1:

The propagation polarization effect in this layer is occurring in response to the resistivity contrast of another layer that is located:

• At the top of the borehole

• At the bottom of the borehole

• At the right of the borehole

• At the left of the borehole

Resistivity question 2:

What is the cause of the separation if the resistivity curves?

• Invasion

• Resistive shoulder bed

• Anisotropy

Resistivity question3:

What is the cause of the resistivity curves separation within the red box?

• It can be attributed to resistivity anisotropy.

• There is a lot of invasion in this porous reservoir.

• There is something wrong with the tool.

Resistivity question 4:

In the blue box, why are the attenuation curves flat?

• The tool failed.

• This formation is too heterogeneous for the attenuation measurement to work.

• The formation resistivity is beyond the operating range of the attenuation measurement.

Resistivity question 6:

In the interval 3000-4000 ft, the separation between the EMP resistivity curves is due to:

• Polarisation effect between layers with contrasting resistivities

• Anisotropy

• Invasion

Resistivity question 5:

In the interval 3000-4000 ft, which resistivity would you use for your water saturation evaluation?

• The deep laterolog resistivity

• The deep phase shift

• The shallow phase shift resistivity

Resistivity question 7:

In this real time data example of a sub-vertical well, the phase shifts are straight lines in the interval down to 575 ft because:

• The tool is not working

• The data is influenced by the presence of the casing

• The phase shift data is saturated at the end of its operating range because of the high resistivity

• There is a polarization horn (it can also happen in sub-vertical wells)

Resistivity question 8:

What is causing the large difference between the deep propagation resistivity P34H and the deep laterolog resistivity RES_BX in the interval marked by the red box?

• The difference is due to invasion

• The propagation tool stopped working in that interval.

• These are polarization horns.

Resistivity question 9:

Why is the deep laterolog resistivity RES_BX reading lower than the deep propagation resistivity P34H in the intervals marked by the blue boxes?

• The difference is caused by the presence of fractures.

• The propagation resistivity suffers from polarization horns.

• The laterolog is seeing more invasion.

Resistivity question 10:

What is causing the large difference between the 2MHz and 400kHz resistivity curves in the interval marked by the red box?

• Invasion

• Polarization horns

• Fractures in OBM