WELL LOGGING

Majid FarooqRoll NO.14Semester 8th

TOPIC:-

The Dipmeter Log

OVERVIEW Introduction Principle &Processing Tools information Uses Interpretation Conclusion References

INTRODUCTION It gives a continuous record of

formation dip or azimuth. It comes from two stage processes….. Modern tool become very sophisticated

because it consist of logging sonde &also positioning sonde.

Interpretation of this log in past require long processing while in recent days processing become easy even in laptop.

PRINCIPLE AND PROCESSING The dipmeter tool measures dip by

comparing the displacements of microresistivity curves from opposing side of borehole wall.

Typically 4 pads are used with a single electrode on each paid,SHDT of SLB has two on each pad.

To derive a dip direction & azimoth from raw,tool produced resistivity curves needs computer processing.

The requirement is to correlate the curves around the borehole as to identify the various displacements.

PROCESSING:-

TOOLS INFORMATION

USES

INTERPRETATION The correctly processed dipmeter log is not

immediately intelligible, it requires a great deal of interpretation.

Dipmeter results show no selectivity, everything is mechanically measured.

Sedimentary and structural interpretation will be processed separately.

Sedimentary interpretation requires a detailed & small scale processing .

Structural interpretation needs same raw data & on broader scale.

INTERPRETATION

STRUCTURAL SEDIMENTARY

Figure 5.2 New micro-resistivity logs combine resistivity with dipmeter data to produce ‘virtual cores’ in three dimensions. Such detailed borehole imaging, with a vertical resolution of less than 8 mm, allows the observation of sedimentary structures in the absence of mechanical core.

CONCLUSIONS Dipmeter is an expensive tool to run, is still

not being used to its full extent, interpretation is to blamed.

During processing each step envolves geologically biased choices,so it must be a geologist who uses the computer.

The great lack in dipmeter work is that there are so few outcrop analogues & models of orientation data.

Recently arrived image logs are considered to replace the dipmeter.

REFERENCES Serra,O., Stowe,I. and Motet

1993.Fundamentals of well log Interpretation, P269-290.

Rider M., 2002. The Geological Interpretation of Well logs, second edition, P169-198.

??

????

THANK YOU.