Gas, Gas Data Qc & Aplication Mud Logging

GAS, GAS DATA QC & APLICATION By: Mohammad Zulfikar Simatupang (051535) (Sept 11th,2008) Mohammed Zulfikar Simatupang

Mohammad Zulfikar

Digitally signed by MohammadZulfikar Simatupang DN:cn=Mohammad Zulfikar Simatupang, o=ADMA-OPCO, ou=RTD,c=AE Date:2008.09.11

Mohammed Zulfikar Simatupang

GAS DATA •

Liberated gas : the gas originally contained in the pore spaces of the rock crushed by the drill bit

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Produced gas : gas obtained from the undrilled part of the formation, due to drilling fluid pressure lower than formation fluid pressure. •

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Mohammed Zulfikar Simatupang

Recycled gas : gas that remains entrained in the mud and is recirculated down hole. Background gas : a minimum gas level, more or less constant, derived from a combination of liberated, recycled and contamination gases Contaminated gas : any gas found in the bore hole that derives from a source other than the formation, due per example to mud additives.

LAG TIME PROBLEM Lag time observed > lag time theoritical

LAG TIME “The correct calculation of lag time will gives a correct depth on which depth are the data coming from, then making a lag time check is so important.”

“Cuttings arrive «late» regarding to ROP, Hole enlargement=>Caving, Washout, reducing hole cleaning effeciency.” Lag time observed < lag time theoritical

Cuttings arrive «early» regarding to ROP,Tight Hole=> STICKY HOLE Shale hydration (Monmorillonite), ...

BUT, IT MAY ALSO BE DUE TO: - Wrong Pump efficiency (Toolpusher data) and/or false adjustment (Data Engineer) - Incomplete or erroneous pipes dimensions (OD & ID) and volumes, ...

Mohammed Zulfikar Simatupang

Gas Data Interpretation

SURFACE LOSSES OF GAS Misrepresentation of gas composition due to differential loss LOSSES FROM BELL NIPPLE FLOWLINE NOT FULL TURBULENCE

OPEN FLOW LINE

ENTRY ABOVE MUD LEVEL

Mohammed Zulfikar Simatupang

GAS CHAIN

Fréquency of analysis 1 to 5 min

Chromatography

Gas trap Air inlet Analysis C1- C5

Gas

Mud Q = 1.5 l/min

Total Gas

Q = 0.5 l/min

Continuous analysis

Mohammed Zulfikar Simatupang

GAS DATA QC Graphs : - TG vs. depth

Tool specifications

- C1/C2 vs. depth

Tool calibration: - Graph TG / Σ (C1 à C5) vs. depth - Graph TG / Σ (C1 à C5)cor  vs. depth with Σ

(C1 à C5)cor = C1+2*C2+3*C3+4*(iC4+nC4)+5*(iC5+nC5)

TG / Σ (C1 à C5)cor  = 1 +/- 20% Mohammed Zulfikar Simatupang

SPERRY SUN TECHNICAL SPECIFICATION

Mohammed Zulfikar Simatupang

GAS CHAIN: CYLINDRICAL GAS TRAP

GAS CHAIN: GAS ANALYZERS - TG: Baseline 1015A - Chromatograph: Baseline 1030A GAS TRAP: Cylindrical Gas Trap GAS LINE: No data available

Mohammed Zulfikar Simatupang

GAS CHAIN: FLOATING GAS TRAP

GAS CHAIN “ GAS ANALYZERS - TG: Baseline 8800 - Chromatograph: Baseline 8900 GAS TRAP: Floating Gas Trap GAS LINE: • Coating : Reinforced plastic • Internal diameter : ¼” • Gas/Air flow rate : controllable 0 – 10 l/mn • Maxi length : > 500 m • Pressure: controllable > 150 mbar  • Drying agent:: Genie filter  • Transit time :

Mohammed Zulfikar Simatupang

GAS ANALYZER: “FID Total Gas Detector BASELMINE 1015A“ “FID Total Gas Detector BASELMINE 1015A“ Detection Type: Gas Flame Ionization Detector  It is a THA (Total Hydrocarbon Analyser).

Calibration Method “Sperry Sun General Gas Detectors Specifications”, suggest to calibrate the gas detector using at least 2 points with known gas concentration canister 

Tool Check: Good response in all the different conditions. Excellent reading linearity at different C1/C2 and C1/C3 ratios. Slight underestimation at low concentration both for C2 and C3 measurements. Slight overestimation at high concentration (C1 equal or more than 25%) only for C2 measurement. Mohammed Zulfikar Simatupang

GAS ANALYZER: FID Chromatograph BASELINE 1030A”

Calibration Method Single point calibration is performed using a compressed gas cylinder at the following nominal concentration: C1, C2 & C3 = 1% nC4, iC4 % nC5 = 0.25%, iC5 normally absent The calibration data are automatically inserted in the INSITE Computer system and a calibration factor is derived using the area under the curve (chromatogram) by a gas integrator analysis software module.  A reduced cycle time of 75 sec for C1 to C4 can be required.

Tool Check: Good response in all the different conditions. Excellent reading linearity at different C1/C2 and C1/C3 ratios. Slight underestimation at low concentration both for C2 and C3 measurements. Slight overestimation at high concentration (C1 equal or more than 25%) only for C2 measurement. Mohammed Zulfikar Simatupang

GAS ANALYZER: DUAL CHANNEL HNU 301 “FID Total Gas Detector HNU 301”

FID Chromatograph HNU 301”

Detection Type: Gas Flame Ionization Detector 

Detection Type: Gas Flame Ionization Detector 

Mohammed Zulfikar Simatupang

GAS ANALYZER: DUAL CHANNEL GC MINI 2 “FID Total Gas Detector  SHIMADZU GC Mini 2”

FID Chromatograph SHIMADZU GC Mini 2” Detection Type: Gas Flame Ionization Detector 

Detection Type: Gas Flame Ionization Detector 

Mohammed Zulfikar Simatupang

GAS ANALYZER: BASELINE 8800 - 8900 “FID Total Gas Detector  BASELMINE 8800“

Calibration Method One concentration (10% C1)

FID Chromatograph BASELINE 8900”

Calibration Method 5 different concentrations Comments Temperature range 0 – 200°C

TOOL CHECK:Quite good response at different concentrations. The main problem highlighted is the systematic underestimation of C2, especially at high C1/C2 ratios (difference between nominal and measured values around 20% at C1/C2 =180). nC4 and iC5 show overestimation only at very low values (less than 100ppm), while nC5 show also Mohammed Zulfikar Simatupang an underestimation (if compared to C1) at 

Sperry Sun Callibration Mixture

Mohammed Zulfikar Simatupang

FIELD EXAMPLE (US306 & US 307) SPERRY SUN

MUDLOGGING CONTRACTOR

GAS DETECTOR TOOL

BASELINE 8800 - 8900

TOOL SPECIFICATION

Chromatograph C1 Saturation Limit = 1 000 000 ppm C1/C2 Separation = 1500 Teperature range = 200 degC Mohammed Zulfikar Simatupang

CHROMATOGRAPHY CALIBRATIONS ON

US307 SPERRY SUN FID

WELL: CONTRACTOR:  APPARATUS:

TO BE FILLED IN

CALIBRATION DATE

GAS BOTTLE COMPOSITION

RESERVAL READINGS

Difference

% ERRORS

OUT

(ppm)

OUT/REF

23/01/09

C1

10000

9963.66

-36.34

-0.4%

23/01/09

C2

10000

9073.54

-926.46

-9.3%

23/01/09

C3

10000

10702.6

702.6

7.0%

23/01/09

iC4

2500

2424.62

-75.38

-3.0%

23/01/09

nC4

2500

2424.62

-75.38

-3.0%

23/01/09

iC5

N/A

Not tested

23/01/09

nC5

2500

2364.05

-135.95

-5.4%

16/02/08

C1

10000

11005.7

1005.7

10.1%

16/02/08

C2

10000

9474.36

-525.64

-5.3%

16/02/08

C3

10000

10106.4

106.4

1.1%

16/02/08

iC4

2500

2637.44

137.44

5.5%

16/02/08

nC4

2500

2498.67

-1.33

-0.1%

16/02/08

iC5

N/A

Not tested

16/02/08

nC5

2500

2509.58

9.58

0.4%

Put the result in excell file to make the comparison easier  Mohammed Zulfikar Simatupang

GAS DATA APLICATION

Mohammed Zulfikar Simatupang

GAS RATIO ANALYSIS (GWD)

Mohammed Zulfikar Simatupang

Wetness Ratio(Wh)

Balance Ratio (Bh)

Character Ratio (Ch)

Taken from “Geosteering Horizontal wells using speed chromatographic gas ratio by D.P.Hawker, Datalog, SPWLA Nov 23rd1999 Mohammed Zulfikar Simatupang

Taken from Advance logging procedures,BHI inteq, 1995.

Mohammed Zulfikar Simatupang

Taken from “Geosteering Horizontal wells using speed chromatographic gas ratio by D.P.Hawker, Datalog, SPWLA Nov Mohammed Zulfikar Simatupang

 A:Slight increase in Wh, BH often be greater then 100, Ch is very low

E: Ideally the Wh & Bh curve will cross, with Wh=17.4 – 40, the narroower the separation the lighter the oil Coal Horizon (rich of Methena & ethane):Wh>17.5, Ch40 and BH