Well Logging-Introduction Chapter Two.ppt

7/28/2019 Well Logging-Introduction Chapter Two.ppt

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Logging Well General Procedures

Chapter Two





Logging Well General Procedures

*In 1929,electrical resistivity logging was

introduced on a commercial basis in

Venezuela,the United States ,and Russia.

*It was a natural move for the

Schlumberger brothers to extend and

develop their experience from one place to

another.



Cementation-2

*The procedure of cementing a casingstring in the borehole to isolate the

productive interval.

*Introduced in Oklahoma in 1920 byHalliburton.

*In 1933 Schlumberger offered the primary

thermometer log to pick the cement top by

recording the heat anomalies from thecuring cement.

*The discovery of Sonic tool in 1961, which

led to the Cement Bond Log (CBL)



Perforation-3

*After the success of early cementingoperations.

*It was required the development of a

method to perforate the casing andthe cementing material facing theproductive interval for production.

*A wireline bullet guns were

introduced in the mid 1930s toperforate the productive intervals.



Correlation Logs-4

*The gamma ray and neutron tools ,unlikeresistivity tools ,represented the first use of

radioactive properties and down hole

electronics in well logging through steel

casing, as well as in air –or gas-filled holes

or in oil-based mud.

*These developments of the gamma ray

scintillation detector in the late 1950s wasanother breakthrough for better correlation

for logs between the boreholes in oil and

gas fields.



Formation Evaluation-5

*Neutron log in combination with gammaray log enhances lithological interpretationsand well-to-well stratigraphic correlations.

*In 1950s,attention was given to the neutron

indicator.poros i ty log as a*This was the first serious attempt to

evaluate formations through casing.

*The introduction of (CNL) compensatedneutron log in 70s that the neutron gained

poros i ty wide acceptance as ameasurement.



Other Developments-6

*Cased hole wireline services have

many other types both mechanical and

electrical, which were developed

throughout the years.

. *In 1950s a complete series of

production logging tools to measure

the nature and behavior of downhole

fluids. *Sophisticated tools for setting

plugs and packers are now available.





Data Processing -8

Signal processing can beperformed on three levels;

1-Downhole in the tools2-Up-hole in the truck

3-Central computingoffice



Data Processing

*Sometime the logging tool is designed to

process data downhole and transmitted to

the surface.

*A Schlumberger Cyber Service Unit(CSU) isa well-site standard digital computer system

carried on a Schlumberger wireline units

throughout the world.

*The computer center offers a more powerful

computers, expert log analysts, more time

and the integration of more data, ex.

Schlumberger computer centers



Data Transmission-9

*The CSU system is able totransmit logs from the well-site

with a suitable communication

link.

*Another CSU system is to be the

receiving station.*Data can be edited or

reformatted before transmission

to reduce the transmission time



Data Transmission

communicationsLOGNET *With thenetwork, graphic data or log

transmittedfrom the wellSatell i te via

site to multiple locations.*A small transportable

communications antenna at the

wellsite permits transmission of welllog data via satellite to a computing

center.



Data Transmission



The End

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Well Logging-Introduction Chapter Two.ppt