It is publishing for to get review my work.

1. Mehran university of
engineering and
technology.
Name: YOUNIS SATTAR
Roll number: K-19PG-06

2. Topic: calculate the
resistivity of formation
water by using inverse
archie equation.

3. Principle
• If a clean, water-bearing zone is present or can be
assumed, Rw can be calculated by using the Archie
equation. The zone or permeable bed in which
water resistivity is determined is selected on the
log. This zone must be 100% water saturated and
must not contain any clay or shale. The bed must
be thick so that the deep investigation resistivity
device is not affected by shoulder beds.

4. The water saturation equation in
general form is.

5. Let's assume for a, m, and n the
usual initial values of 1, 2, and 2,
respectively (although other
values for a, m, and n may be
more appropriate). We have:

6. In a water zone, Sw = 1, thus
Equation 4 becomes

7. Procedure
• #Equipments:
• The procedure to determine Rw from the Archie
equation is outlined as follows. The data that are
required include Rt (or Ro) from deep-reading
resistivity tools such as deep induction (ILd) or
deep laterolog (LLd) and porosity log(s).

8. Deep laterlog.
The deeo laterlog tool
provides two resistivity
measurements:
1/A. Shallow reading which
investigates,the formation
near the borehole
2/A deep reading which
measures farther out in the
formation where its less
disturbed by drilling fluid.

9. Procedure
• After correlating logs for depth mismatch, a clean,
water-bearing zone is located. If using an induction
log, the minimum thickness should be 15 ft4.572 m
• 180 in. For a laterolog, the minimum thickness
should be 4 ft1.219 m
• 48 in.

10. Assumptions and limitations
• It is assumed that there are no clay or conductive
minerals in the water-bearing zone, that the zone is
clean, and that the invasion is shallow enough for
resistivity tools to be unaffected by it. This method
only works in clean, waterbearing reservoirs. It is
typically unreliable in highly fractured or vuggy
reservoirs.