This document discusses pipeline line loss, which is the difference between the quantity of crude oil at the off take and delivery ends of a pipeline. It identifies the key factors that influence line loss, including measurement errors related to tank dip, temperature, density, and water content. Other factors like evaporation, wax deposition, and pilferage are also discussed. The document analyzes line loss data from several pipelines in India and North America over multiple years and the impact of factors like water content, measurement errors, and wax deposition. It outlines steps taken to improve measurement uniformity and control water to reduce line losses.
2. A STUDY ON PIPELINE LOSS
TRANSPORTATION/LINE LOSS IS THE
DIFFERENCE BETWEEN THE QUANTITY
OF CRUDE OIL AT OFFTAKE AND
DELIVERY ENDS TAKING INTO ACCOUNT
INTERNAL CONSUMPTION AND LINE
STOCK QUANTITY.
LINE LOSS IS EXPRESSED IN
PERCENTAGE ON DRY TONNES
DELIVERED.
3. FACTORS INFLUENCING THE LINE LOSS.
MEASUREMENTAL ERROR
TANK DIP MEASUREMENT
TANK TEMPERATURE
DENSITY
WATER CONTENT
OTHER FACTORS
EVAPORATION LOSS IN ENROUTE TANKS
WAX DEPOSITION IN THE LINE
PILFERAGE
4. IMPACT OF MEASUREMENTAL ERROR
TANK DIP:
FOR EACH ERROR OF ONE CM. IN TANK DIP,THE
VOLUME LOSS OR GAIN WILL BE 4KL TO 36 KL
DEPENDING ON TANK SIZE
TANK TEMPERATURE:
FOR AN ERROR OF ONE DEGREE, THE VARIATION
IN CRUDE VOLUME WILL BE 0.08 TO 0.1%
5. IMPACT OF MEASUREMENTAL ERROR
DENSITY:
DENSITY IS A VERY IMPORTANT PARAMETER
FOR CRUDE OIL TRANSANCTION.A VARIATION IN
DENSITY BY 0.001 WILL RESULT IN 0.1%
VARIATION IN WEIGHT
WATER :
WATER CONTENT DIFFERENTIAL AT INPUT &
DELIVERY HAS A DIRECT IMPACT ON LINE LOSS
OR GAIN. MOREOVER, HIGH WATER CONTENT
AFFECTS SAMPLING PERFORMANCE.
7. LINE LOSS % FOR LAST FIVE YEARS
3
Line loss %
2.5
2
1.5
1
0.5
0
1998-99 1999-00 2000-01 2001-02 2002-03
8. LINE LOSS VIS-À-VIS WATER CONTENT
5
4.5
Loss %
4
Water %
3.5
3
2.5
2
1.5
1
0.5
0
1995- 1996- 1997- 1998- 1999- 2000- 2001- 2002-
96 97 98 99 00 01 02 03
9. IMPACT OF WATER DIFFERENCE
ON LINE LOSS
3 Actul Loss
%
2.5
Loss %
without
2 Unaccounted
Water
1.5
1
0.5
0
1995- 1996- 1997- 1998- 1999- 2000- 2001- 2002-
96 97 98 99 00 01 02 03
10. IMPACT OF WATER % ON WATER
DIFFERENCE
Unaccounted Water
(X 10,000Tonnes)
8 Water %
7
6
5
4
3
2
1
0
1995-96 1996-97 1997-98 1998-99 1999-00 2000-01 2001-02 2002-03
12. LINE LOSS IN OTHER CRUDE
PIPELINE IN INDIA
SMPL (IOCL)
1999-2000- 0.106%
2000-2001- 0.105%
HBCPL(IOCL)
2002-2003- 0.013%
ONE TO ONE COMPARISION WITH OIL PIPELINE
IS DIFFICULT DUE TO SYSTEM DIFFERENCE.
13. LINE LOSS IN OTHER CRUDE PIPELINE
IN NORTH AMERICA
FEDERAL ENERGY REGULATORY COMMISSION
DOCUMENT ON PIPELINE TARIFF REFERS TO
DETERMINATION OF VOLUME AND
DEDUCTIONS OF CRUDE OIL AS QUOTED
BELOW :
“THREE TENTH OF ONE PERCENT (0.30%) WILL
BE DEDUCTED FROM ALL CRUDE PETROLEUM
RECEIVED FOR TRANSPORTATION AT POINT OF
ORIGIN AND RETAINED BY CARRIER TO COVER
LOSSES DUE TO SHRINKAGE AND EVAPORATION
INCIDENT TO PIPELINE TRANSPORTATION. THIS
LOSS ALLOWANCE ADJUSTMENT WILL BE MADE
FROM SHIPPER’S INVENTORY.”
14. COMPARATIVE STUDY OF LINE LOSS% BY VOLUME
AND WEIGHT
W et at 15' C
3
Dr y Tonnes
2.5
2
1.5
1
0.5
0
19 19 20 20 20
98- 99- 00- 01- 02-
99 00 01 02 03
15. STEPS TAKEN TO CONTROL
LINE LOSS
A.UNIFORMITY IN MEASUREMENT
1.SAMPLING
AUTO SAMPLER INSTALLED IN
PS2,ONGCL FROM AUG’2002 . NEW
SAMPLER INSTALLED IN PS2,OIL
CRUDE IN JAN’2003.
NECESSARY PIPING MODIFICATIONS
CARRIED OUT AT PS2, OIL AND
ONGCL(AUG’02) AND BRPL (APR’02)
AS PER API/IP GUIDELINE
16. STEPS TAKEN TO CONTROL
LINE LOSS
MECHANICAL MIXER INSTALLED AT
ALL TESTING POINT SINCE APR’02
AND AT IOC,GUWAHATI IN DEC’02.
2.TESTING
SIMILAR TESTING PROCEDURE ADOPTED
AT PS2 FOR BOTH OIL AND ONGCL
CRUDE AS WELL AS AT DIGBOI REFINERY
IN RESPECT OF WATER MEASUREMENT.
17. STEPS TAKEN TO CONTROL
LINE LOSS
B. CLOSE SUPERVISION
LAB TESTING AT REFINERY ENDS ARE
CARRIED OUT IN PRESENCE OF OIL
CHEMISTS
C. CONTROL IN WATER
STRICT CONTROL OF WATER AT INTAKE
.
WITH ALL THE ABOVE MEASURES ,A
SIGNIFICANT IMPROVEMENT IN LINE LOSSES HAVE
BEEN OBSERVED DURING LAST YEAR AND AS
WELL AS FIRST QUARTER OF THE CURRENT YEAR.
20. COST DUE TO LINE
LOSS(RUPEES)
AMOUNT OF LOSS
COSIDERING 3MTPA CRUDE
OIL DELIVERY @ Rs. 8000/-
PER MT CRUDE AND 0.40%
LINE LOSS IS
9.6 CRORES.
21. LINE LOSS DUE TO WAX DEPOSITION
AV. WAX PS1-RS2 SECTOR=12,000 KG PER
YR.
ANNUAL PIGGING =3000 KG.
TOTAL WAX =15,000 KG PER YR
LINE LOSS=0.0005%
.
22. IP74 AND IP 358-DIFFERENCE
IP 74 IS FOR DETERMINATION OF WATER CONTENT OF
PETROLEUM PRODUCTS,INCLUDING CRUDE
CARRIER FLUID USED ARE TOLUNE,XYLENE,PETROLEUM
DISTILLATE ETC.
REPORTING NEAREST TO 0.1%
REPEATABILITY-0.1ml
IP358 IS FOR WATER CONTENT IN CRUDE OIL
CARRIER FLUID IS XYLENE
REPORTABILITY NEAREST TO 0.025 ML
REPEATABILITY-0.08 ml
MORE ACCURATE
23. IMPACT OF DENSITY
Assumptions
Gross volume of wet crude at tank temperature 10,000 KL
Tank temperature 28 deg.C
Density of the crude at 15 deg.C 0.8770 0.87800 0.8800
Factor to covert vol at 15 deg C 0.9896 0.9896 0.9897
Gross volume of wet crude at 15deg.C 9896 KL 9896KL 9897KL
Factor to convert to mass 0.8759 0.8769 0.8789
Wt. Of wet crude at 15deg.C 8668 T 8678 T 8698 T
Variation 10 T 30 T
% Variation (0.001) 0.115 0.115
24. IMPACT OF TEMPERATURE
Assumptions
Gross volume of crude oil at tank temperature 10,000kl
Average tank temperature 28deg.C 27deg.C 26deg.C
Density at 15deg.C 0.8770
Factor to convert volume at 15deg.C 0.9896 0.9904 0.9912
Volume at 15deg.C 9896KL 9904KL 9912KL
Factor to convert to mass 0.8759 0.8759 0.8759
Wt. Of wet crude at 15degC 8668 8675 8682
Variation in KL 8KL 8KL
Variation in mass 7MT 7MT
% In Variation 0.08 0.08