CHAPTER 3: SIMULATION STUDY IN SOUTH SANGU– 4
3.2 Back calculated coefficient of friction from the analysis
3.2.1 12.25’’ section (Tripping in condition)
The simulated Tripping in Hook Load data for different friction factor (0.2 to 0.4) from 0 m (MD) to 2850 m (MD) and corresponding manually filtered real time data is graphed below:
Figure 3.8: Simulated Hook Load graph for different FF in cased and open hole section (Tripping in) 0
200 400 600 800 1000 1200
0 250 500 750 1000 1250 1500 1750 2000 2250 2500 2750 3000
Measured Depth (m)
Hook Load (KN)
Simulated Tripping in data for 12.25'' section
FF = 0.2 FF = 0.3 FF = 0.4
Cased Hole Section Open Hole Section
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Figure 3.9: Comparison of Hook Load data with Real time data (Tripping in) Analyzing the real time data : (Tripping in 12.25’’ section)
1. Region A: From the above figure it is clear that the cased section from 0m to 1250 m has no impact of friction factor on Hook Load as the well is vertical throughout the casing section.
The real time data shows a bit higher value than the simulated one due to hydrodynamic viscous force which is already discussed in the theory part.
2. Region B : In this open hole region the real time tripping in data is matched with the simulated data having the FF 0.20. The region extends from 1250 m(MD) to 1650 m(MD).
3. Region C: In this open hole region the open hole real time tripping in data is matched with the simulated data having the FF 0.25.The region extends from 1650 m (MD) to 2250 m (MD).
4. Region D : In this open hole region the real time tripping in data is matched with the simulated data having the FF 0.30. The region extends from 2250 m (MD) to about 2625 m (MD).
5. Region E : In this region from the depth of around 2625 m (MD)the Hook Load data increased and show the FF 0.35 for the rest of the open hole part.
0
Comparison between simulated and real time data on 12.25'' section for tripping in condition
Cased Hole Section Open Hole Section
39 3.2.2 12.25’’ section (Tripping out condition)
The simulated Tripping out Hook Load data against the measured depth (MD) for different friction factor (0.2 to 0.4) from 0 m (MD) to 2850 m (MD) and corresponding manually filtered real time data is graphed below:
Figure 3.10 : Simulated Hook Load graph for diff. FF in cased and open hole section (Tripping out) 0
200 400 600 800 1000 1200 1400 1600 1800
0 250 500 750 1000 1250 1500 1750 2000 2250 2500 2750 3000
Hook Load (KN)
Depth (m)
Simulated Tipping out data of 12.25'' section
FF = 0.2 FF = 0.3 FF = 0.4 Cased Hole section Open Hole Section
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Figure 3.11: Comparison of Hook Load data with Real time data (Tripping out)
Analyzing the real time data : (Tripping out 12.25’’ section)
1. Region A: From the above figure it is clear that the cased section from 0m to 1250 m has no impact of friction factor on Hook Load as the well is vertical throughout the casing section.
The real time data shows a bit higher value than the simulated one due to hydrodynamic viscous force which is already discussed in the theory part.
2. Region B: In this open hole region the real time tripping out data is matched with the simulated data having the FF 0.30. The region extends from 1250 m(MD) to 2375 m(MD).
3. Region C: In this open hole region the open hole real time tripping out data is matched with the simulated data having the FF 0.4 .The region extends from 2375 m (MD) to 2850 m (MD).
0 200 400 600 800 1000 1200 1400 1600 1800
0 250 500 750 1000 1250 1500 1750 2000 2250 2500 2750 3000
Hook Load (KN)
Depth (m)
Comparison of real time data with simulation
FF = 0.2 FF = 0.3 FF = 0.4 Real time data Region A :
FF is not detectable
Region B :
FF is 0.3 Region C : FF is 0.4
Cased Hole section Open Hole Section
41 3.2.3 8.5’’ section (Tripping in condition)
The simulated Tripping in Hook Load data (Open hole section) for different friction factor (0.2 to 0.4) from 2850 m (MD) to 3450 m (MD) is shown below. As some adjustment to overcome the input error in simulator constant 90 KN hook load is added with the original simulated data and the corrected simulated data also is expressed below :
Figure 3.12: Comparison of Hook Load data with Real time data (Tripping in) Analyzing the real time data : (Tripping in 8.5’’ section)
Region A: In this open hole region real time hook load data does not match with any corrected simulated data but showing FF greater than 0.4. This open hole region extends from 2850 m( MD) to 2990m (MD).
Region B: In this open hole region real time hook load data is matched with the corrected simulated data of FF 0.3. this open hole region extends from 2990 m (MD) to 3100 m (MD).
Region C: In this open hole section the real time hook load data is matched with the corrected simulated data of FF 0.35. This open hole region is extends from 3100 m (MD) to 3250m (MD).
Region D: In this open hole region the real time data hook load data is matched with the corrected simulated data of FF 0.4. This region extends from 3250 m (MD) to 3400 m (MD).
Region E: In this region from the depth of 3400 m (MD) the Hook Load increases sharply indicating the FF to be more than 0.4.
Comparison of Hook Load in tripping in condition for Open hole section (2850m to 3450m)
42 3.2.4 8.5’’ section (Tripping out condition)
The simulated Tripping out Hook Load data (Open hole section) for different friction factor (0.2 to 0.4) from 2850 m (MD) to 3450 m (MD) is shown below. As some adjustment to overcome the input error in simulator is needed, aconstant 115 KN hook load is added with the original simulated data.
Both original simulated data and corrected simulated data are plotted with the real time data below:
Figure 3.13 : Comparison of Hook Load data with Real time data (Tripping out)
Analyzing the real time data : (Tripping out 8.5’’ section)
Region A: In this open hole region real time tripping out hook load data is matched with the corrected simulated data of FF 0.2. This open hole region extends from 2850 m( MD) to 2975m (MD).
Region B: In this open hole region real time hook load data is matched with the corrected simulated data of FF 0.3. this open hole region extends from 2975 m (MD) to 3230 m (MD).
Region C: In this open hole section the real time hook load data is matched with the corrected simulated data of FF 0.4. This open hole region is extends from 3230 m (MD) to 3375m (MD).
Region D: In this open hole region the real time hook load data is gone above the simulated line of FF 0.4 which shows the FF in this region is greater than 0.4. This region extends from 3375 m (MD) to the rest of the depth.
Comparison of HKLD data in tripping out condition for close hole section (2850m to 3450m)
OHFF 0.2
43 3.2.5 Summary of the result
Finding out an average coefficient of friction in South sangu 4 is basically divided into two parts. First part is 12.25’’ section where the well bore (open hole) extends from 1250 m to 2850 m and the second part is 8.5’’ section where the open hole section was extended from 2850 upto the 3450m.
The summary of the result is given below 12.25’’ section
For Tripping in condition the minimum and maximum FF is found 0.2 and 0.35 respectively. And for Tripping out condition the minimum value and maximum value we get is 0.2 and 0.4.
From the above result we can come to a conclusion that the FF in this section will vary from 0.2 to 0.4.
8.5’’ section
For Tripping out condition the minimum and maximum FF is found to be o.2 and greater than 0.4 respectively. In Tripping in condition the minimum and maximum value of FF are 0.3 and greater than 0.4 respectively. In both cases we observe the higher value of FF which is more than 0.4 at the lower part of the section.
From the above result we can come to an end that the FF in this section varies from 0.2 to 0.5 or higher.
From the above result a profile of Friction factor is graphed below for the open hole section. And one FF ratio graph is plotted where the ratio greater than 1 is a very clear indication of pack off.
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Figure 3.14: FF profile for both Tripping in and Tripping out operation in Open Hole
Figure 3.15: ratio of FF in Tripping in and Tripping out 0
500 1000 1500 2000 2500 3000 3500 4000
0 0.1 0.2 0.3 0.4 0.5
Depth, m
Coefficient of friction
FF for Trippping in FF for Tripping out
0 500 1000 1500 2000 2500 3000 3500 4000
0 0.5 1 1.5 2
Depth, m
Friction factor ratio
Friction ratio for tripping in Friction ratio for tripping out
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