Mud Logging

Mud LoggingMud Logging also called the Hydrocarbon Logging, involves monitoring and recording of variety of data related to bore hole and drilling process..... Like1, Gas detection2, Gas Analysis3, Drill cutting Identification and Analysis4, ROP5, Mud Tank Volume Monitoring6, Changes in flow and sudden influx of gas.

Portable cable or Unit.Electronic instruments to monitor gas, ROP, pumps and flow rates.Gas trap in the mud flow line.

Mud Logging Equipment

Mud Logging TechniquesDrilling mud from the bottom of the hole brings Drill cuttings and Gas/Oil

Samples are collected at the screens called shale shaker, and then washed and cleaned for examination and storage.

A microscope is used to look at the samples and describe them.

A UV Box with an ultra voilate tube is used to detect the presence of any hydrocarbon in the sample.

Gas from the mud is extracted by an instrument called Gas Trap, and is sent through a tube to logging unit for measurement.

This gas is passed through a meter called Hydrocarbon detector which measures the amount of gas prsent in the mud.

Analyasis of Gas is then carried outby a Gas Chromotograph to give break down from C1 to C5.

Gas Detection

Depth, ROP, and Mud Tank Volume & Level.Sensors are mounted on the Rig to Monitor depth and rate of drilling progress.

ROP Varies with the Hardness or Softness of Rocks.

Monitoring of increase & decrease of the level of mud or any sudden change in the level, indicates inflow or loss of circulation.

This alerts drill crew for any potential hazard.

This is basically used for,

1, Show Evaluation

2, Reservoir and Litho logical Description

3, Geological correlation and formation identification

4, verification of Wire line Log response.

Cutting Sample Analysis

Cutting Sample AnalysisSampling Interval. Collected at a regular intervals of 1-10 meters, depends upon ROP.Sample Lag. This is the time difference b/w when the rock is first cut and when the sample is caught at the surface. Sample Preparation. Wet or un washed" samples are packed in cloth or plastic bags.

Dry Samples or washed samples are washed, cleaned and examined under a microscope and then dried for storage in paper or envelop.

All Sample Bags are marked with depth , well name and company name .

Cutting Sample AnalysisSample Analysis.Visual examination under microscope for,1, Rock Type2, Color3, Hardness4, Grain Size5, Sorting6, Cementation materials7, Sedimentary Structures8, Visual Porosity9, Hydrocarbon Show

1, Mud logging is applied on Wildcat or exploratory wells as well as field development wells,

2, High pressure wells where it helps in preventing potential blow out.

3, Where continuous monitoring is required to make changes in the drilling program, take cores, run wire line logs pick casing point, or decide on DST.Application of Mud Logs