DEGASSER TECHNOLOGY:

The key for good data

Gas Line

SpareGas Line

DryingAgent

Total GasDetector

Chromato-graph

CompressedAir Supply

Vent

Vent

CalibrationSystem

RecordingEquipment

Degasser

LoggingUnit

Return Mud FlowFrom Well

In-lineH S Sensor2

Pump

Pump

Surface gas detection processThere are 3 main parts to any gas detection service today and Geoservices have focused on all of them.

Gas Extraction

Gas Transport

Gas Analysis We measure the amount of extracted gas in the gas air mixture , at the trap suction: It is a gas in Air measurement

Variables in measurement: Losses of gas along flow lineVariables in measurement: Losses of gas along flow line

Misrepresentation of gas composition far from well head

OUT

IN

Flow line not full.Turbulences -Mixing with air

Losses at bell nipple. Degassing depends on molecular weight

Open flow lineSpontaneous degassing

Flow line data104

103

102

10

1

Shales shaker data104

103

102

10

1

Time (A.U.)

Time (A.U.)

Spontaneous degassing of mud decreases gas quantity far from well head

Change gas composition: heavier remains longer in mud than lighter

Gas

qua

ntity

(ppm

)G

as q

uant

ity (p

pm)

C1C2C3iC4nC4iC5nC5

Impact of degasser position

Rotor CouplingPlate

ConnectionBox

Gas/airOutlet

CylindricalTank

Decanting Tube

CheckValve

Float

Motor

Air Inlet

Mud Outlet

RecommendedMud Level

Degassing Chamber

Rotor Blade

Tubular Mounting Arms

Rubber Hose,12mm I.D.

Rubber Hose,8mm I.D. To Mud Logging Unit

Installed at Shaker header boxNo volume or flow control

Conventional gas extractor

Constant VolumePump

Motor driving both Agitator and pump - Constant ratio

Gas Outlet

Self cleaning mud intake probe

Sealed extraction chamber

Installed in the flow line

Constant mud and air flow rate

Increased extraction efficiency

Qualitative gas extraction

Constant volume gas extractor

The benefits of a constant volume trapThe benefits of a constant volume trap

106

105

104

103

102

10

106

105

104

103

102

10

Conventional degasser

Constant volume degasser

Time (A.U.)

Time (A.U.)

Gas

qua

ntity

(ppm

)G

as q

uant

ity (p

pm)

TGC1C2C3iC4 and nC4 (dashed)iC5 and nC5 (dashed)

Conventional degasser: spurious peak due to mud level fluctuations

Constant volume degasser: no spurious peak, consistent with fluid reservoir composition

106

105

104

103

102

10

105

104

103

102

10

1Time (A.U.)

Time (A.U.)

Gas

qua

ntity

(ppm

)G

as q

uant

ity (p

pm)

TGC1C2C3iC4 and nC4 (dashed)iC5 and nC5 (dashed)

Conventional degasser

Constant volume degasser

Conventional degasser: decrease of gas detected due to inadequate supply of mud(Trap Starvation)

Constant volume degasser: no decrease of gas quantity, consistent with fluid reservoir composition

The benefits of a constant volume trapThe benefits of a constant volume trap

Constant volume/temperature fluid extractor (Flex)

Repeatable gas extraction

Gas In correction

On site extraction calibrationSealed Extraction Chamber

Heater

Mud Level Sensor

Self Cleaning Mud Intake Probe

Pump

Temperature sensors

Constant volume

Constant Temperature

Constant Air/Mud Factor

Specially designed mud outlet

RPM sensorsConstant Agitation speed

1st difference: volumetric/flow rate ratio difference

0.670.5 l/min0.3 l/minFlex

30.5 l/min1.5 l/minGZG

Ratio of Mud Flow/Gas FlowAir flow rateMud Flow

rateDegasser

Assuming any other parameters constant, concentrations of extracted gas expected to be 4.5 times less with Flex compared to GZG

For light components, GZG can have higher readings than Flex …

÷ 4.5

Improved gas extraction: air and mud flow rate

2800 rpmFlex

1300 rpmGZG

StirringDegasser

2nd difference: stirring 3rd difference: temperature

70°C(WBM)/90°C(OBM)Flex

No control/regulationGZG

Mud temperatureDegasser

Higher mud/gas contact area with Flex

Higher and constant stirring rpm thus increases exchange kinetics

Shift equilibrium to higher gas concentration

Increase exchange kineticsReproducible gas extraction conditions

Improved gas extraction: agitation and temperature

GAS OUT

GAS IN

Positioning Flex Out and In probes

Extractor designed for Deep Water condition

FLAIR Deep Water DataStandard Deep Water Data

High light components readingsNo C3+ readings

Fluid data up to C5 and more

Standard measurements overestimate light HC components

C3+~0

Good heavies

Coherent ratios

C1-C8 boiling points

liquid80.1 °C6H6Benzene

liquid126 C8H18octane

liquid98.4 C7H16heptane liquid68.7 C6H14hexane liquid36.1 C5H12pentane

gas-0.5 C4H10butane

gas-42.1 C3H8propane

gas-88.6 C2H6ethane

gas-162 CH4methane

State (25oC, 101.3kPas

Boiling Point (oC) Molecular Formula Name

Deep Off-shore Mud temperature 15 °C

Extractor designed for Deep Water condition

Standard Deep Water Data FLAIR Deep Water Data

Conclusion: Degasser evolution from Gas Trap to Fluid Extractor

Repeatable gas extraction

Gas In correction

On site extraction calibrationConstant mud and air flow rateIncreased extraction efficiencyQualitative gas extraction

No volume or flow control