WEEKLY REPORT

Submitted to:
Mr. Xie Fei

Submitted by:
Awais Tariq

Topic:
Wireline Logging

Date:
02-02-2020

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 Table of Content

1.1: Wireline:............................................................................................................................3
1.2: Wireline Logs:...................................................................................................................3
1.3: Wireline Unit:....................................................................................................................3
1.4: Wireline Tools:..................................................................................................................3
1.5: Open hole logging:............................................................................................................4
1.5.1: SP:...................................................................................................................................5
1.5.2: Gamma ray.....................................................................................................................5
1.5.3 Photoelectric effect..........................................................................................................6
1.5.4 Resistivity:........................................................................................................................6
1.5.5 Porosity:...........................................................................................................................6
1.5.6 Density:.............................................................................................................................6
1.5.7 Correlation:.....................................................................................................................6
1.5.8 Sonic Tools:......................................................................................................................7
1.6: Calipers:.............................................................................................................................7

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1.1: Wireline:
Wireline refers to a cabling technology used by operators of oil and gas wells to lower
equipment or measurement devices into the well for the purposes of well intervention,
reservoir evaluation, and pipe recovery. Tools inserted into the well for both workover and
logging efforts, wirelines and slicklines are very similar devices. While a slickline is a thin
cable introduced into a well to deliver and retrieve tools downhole, a wireline is an electrical
cable used to lower tools into and transmit data about the conditions of the wellbore called
wireline logs. Usually consisting of cables, wirelines are used to perform wireline logging.

1.2: Wireline Logs:

Wireline logs measure formation properties in a well through electrical lines of wire.
Different from measurement while drilling and mud logging, wireline logs are constant
downhole measurements sent through the electrical wireline used to help geologists, drillers
and engineers make real-time decisions about drilling operations. Wireline logs can measure
resistivity, conductivity and formation pressure, as well as sonic properties and wellbore
dimensions. The logging tool, also called a sonde, is located at the bottom of the wireline.
The measurements are taken by lowering the wireline to the prescribed depth and then raising
it out of the well. The measurements are taken continuously on the way up, in an effort to
sustain tension on the line.

1.3: Wireline Unit:

Wireline is a term used for a cabling technology used by operators of oil and gas wells to
lower equipment or measurement devices into the well for the purposes of well intervention,
reservoir evaluation, and pipe recovery. There are two types of wireline unit, first one is
Wireline truck and the second one is Wireline Skid, Wireline trucks is used in onshore and
wireline skid is used in offshore operations.

1.4: Wireline Tools:

Wireline tools are specially designed instruments lowered into a well bore on the end of the
wireline cable. They are individually designed to provide any number of particular services,
such as evaluation of the rock properties, the location of casing collars, formation pressures,
and information regarding the pore size or fluid identification and sample recovery. Modern
wireline tools can be extremely complicated, and are often engineered to withstand very
harsh conditions such as those found in many modern oil, gas, and geothermal wells.

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Pressures in gas wells can exceed 30,000 psi, while temperatures can exceed 500 deg
Fahrenheit in some geothermal wells. Corrosive or carcinogenic gases such as hydrogen
sulfide can also occur downhole. To reduce the amount of time running in the well, several
wireline tools are often joined together and run simultaneously in a tool string that can be
hundreds of feet long and weigh more than 5000 lbs.

1.5: Open hole logging:

Open hole logging devices are used to characterize subsurface formations. Common
formation attributes that may be characterized include

 Storage capacity of the formation, which normally includes porosity and fluid saturations
 Fluid properties, which include density, gas to oil ratio, API gravity, water resistivity and
salinity, temperature, and pressure
 Geological setting, which may include structural or stratigraphic dip and reservoir details

Figure 1: Open hole logging

The basic open hole wireline logging devices can be divided into four general groups, as
shown in Table 1. The correlation and lithology devices are used primarily to correlate
between wells and to discriminate reservoir from nonreservoir rocks. The resistivity devices
are used to determine formation resistivity at varying distances from the wellbore, which is

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used for correlation and the determination of water saturation. The lithology and
porosity devices are used to determine both lithology and porosity.

Types Devices

Correlation and lithology Spontaneous potential

Gamma ray

Photoelectric effect

Resistivity Induction

Laterolog

Microresistivity

Porosity and Lithology Density

Neutron

Sonic

Photoelectric effect

Table 1: Open hole logging devices

1.5.1: SP:
Spontaneous potential (SP) is a natural voltage or electrical potential that arises due to
differences in the ionic activities (relative saltiness) of the drilling mud and the formation
waters. This potential can be used to correlate formations between wells, to indicate
permeability, and to estimate formation water resistivity.

1.5.2: Gamma ray

Gamma rays tools measure the natural radioactivity of the formation. This radioactivity is
emitted primarily from potassium in the structure of clay minerals, radioactive salts in the
formation waters, radioactive salts bound to the charged surfaces of clay minerals, potassium
associated with feldspars, and radioactive minerals associated with igneous rocks and rock

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fragments. The gamma ray response is used for correlation of formations between wells and
for estimating volume shale and/or volume clay minerals.

1.5.3 Photoelectric effect

The photoelectric effect, or P.e, measures a formation's ability to absorb gamma rays. The
absorptive abilities of formations vary with lithology. The photoelectric absorption is
recorded as a supplementary measurement to the formation density measurement, using
common detectors and radioactive sources.

1.5.4 Resistivity:
Resistivity tools are primarily used for correlation and to determine the volume of the pore
space saturated with water. Resistivity tools can be divided into three characteristic types:
induction, laterolog, and microresistivity tools. The three types each have their individual
applications, advantages, and limitations,

1.5.5 Porosity:
Each of the porosity tools—density, compensated neutron, sonic, and photoelectrical effect—
can be used to estimate porosity when lithology and fluid properties are known. (Methods for
estimating porosity from these devices individually are described in Standard interpretation.)
When both porosity and lithology are unknown, two or more of the devices can be used
together to determine both porosity and lithology.

1.5.6 Density:
The density tool measures the apparent density of the formation using a radioactive source
that bombards the formation with high energy gamma rays and then measures the number of
lower energy gamma rays returning to the detectors. The detectors and source are mounted in
a pad that is forced against the borehole wall. The measurement attempts to correct
automatically for the effects of mudcake.

1.5.7 Correlation:
Correlation devices are used to identify common formations between wells and to distinguish
potential reservoir rocks from nonreservoir rocks. These devices make use of three different
physical phenomena: spontaneous potential, gamma rays, and photoelectric effect.

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1.5.8 Sonic Tools:
Sonic devices measure the velocity of various acoustic waves, most notably compressional,
shear, and Stoneley waves. The velocity of the waves is a function of the elastic properties
and the density of the formation. Logs normally present the inverse of velocity, called
the interval transit time or delta t (Δt).

1.6: Calipers:
Calipers come in a wide variety of types, the most common being one-arm, two-arm, three-
arm, four-arm, and six-arm. One-arm calipers use the mandrel of the logging device as one
side of the caliper and an arm extending out from the body of the sonde as the other. This
technique is commonly used in density measurements. This configuration typically measures
the long axis of an elliptical borehole. The measurement is unable to characterize accurately
hole size changes less than the tool length on the “tool” side of the measurement.