Well Logging and Thermal MethodAsst. Lecturer: Amir AbdelazizGeology Department, Helwan University

1. Calipar

tool :

1. Calipar tool :

Uses of the caliper log:

Calculation of mud cake thickness:

hmc = (dbit – dh)/2, where h stands for the hole, in inches.

Measurement of borehole volume:

Vh = (dh2/2)+1.2%, in liters' per meter.

Measurement of required cement volume:

V cement = 0.5 *(dh2 – d2 casing) + 1%, in litres per metre.

• Determination of the resistivity of mud (Rm):

1- Measurement by use of Resistivity Meter:-

2- Empirical Method:-

In Fahrenheit In Celsius

• Determination of the resistivity of mud filtrate (Rmf):

1) Measurements by Resistivity Meter:-

2) Estimation from the Resistivity of the Mud:- (empirical method)

Rmf =Km(Rm)1.07

Where K varying between 0.847 – 0.35

• Determination of the resistivity of mud-Cake (Rmc):

• 1- Measurement by Resistivity Meter• 2- Estimation from Mud Resistivity

A. TEMPERATURE GRADIENT:

It is important to determine

the temperature opposite each

level examined in order to take

this influence into account in

the quantitative interpretation

of the log measurements since

the temperature influences

resistivities as well as the

density of fluids, the hydrogen

neutron index, the sonic transit

time in fluids, etc.

Formation temperature varies

with depth, and it is necessary

therefore either to have a

continuous measurement

(temperature well logging) or to

know the temperature at two

given depths and to inter-or

extrapolate

Geothermal gradient is the rate of increasing temperature with respect to

increasing depth in the Earth 's interior it is 22.1°C per km of depth (1°F per 70

feet of depth) in most of the world.

Geothermal gradient is the rate of increasing temperature with respect to

increasing depth in the Earth 's interior it is 22.1°C per km of depth (1°F per 70

feet of depth) in most of the world.

Effect of temperature in Hydrocarbon generation:

A fine-grained sedimentary rock

containing at least 1 to 2% of organic

matter can play the role of a source rock.

Under the influence of temperature and

pressure, the organic matter contained in

the source rock is gradually converted

into kerogen, which is distributed

throughout the rock as small particles.

The kerogen starts to mature at

temperatures of 60 to100°C (at depths

below 2000m).

Effect of temperature in Hydrocarbon generation:

The increasing temperature and

pressure, as burial depth increases,

breaks and reorganizes molecules. The

kerogen starts to generate hydrocarbons:

I. Oil first (oil window)

II. Gas at higher temperatures and

pressures (gas window).

Effect of temperature in mineral formation:

In Earth’s mantle, lava cools as it rises, forming solid rocks in our planet’s crust.

The lava forms when tectonic plates – the fractured slabs of crust – are shoved

back down under each other into the mantle and melt. In this way, a balanced

cycle of rock formation and re melting continues through the ages.

Effect of temperature in mineral formation:

At depth, slow-cooling lava forms coarse-grained, volcanic rock such as granite.

Finer-grained rock such as basalt occurs when lava erupts or oozes to the surface

and cools quickly.

Effect of temperature in mineral formation:

At depth, slow-cooling lava forms coarse-grained, volcanic rock such as granite.

Finer-grained rock such as basalt occurs when lava erupts or oozes to the surface

and cools quickly.

Effect of temperature in groundwater:

Another variation of the use of temperature surveys is the detection of lateral

changes in permeability. (Detection of permeability variations by a shallow

geothermal technique).

Effect of temperature in groundwater:

Temperature surveys of groundwater have taken on new significance as the

several forms of geothermal energy become more important. Principally,

shallow groundwater has great potential as a heat source for heating.

Uses of Geothermal Energy ( Heat effects):

I. In factories

II. In farms

III. At homes

Uses of Geothermal Energy ( Heat effects):

I. In factories

II. In farms

III. At homes