De waxing

De-waxing & Cleaning of 212Km long Loop Line to make suitable for

Pumping Products.

RS 2172 KM.ROW

194 KMRS3

214.3 KM

NRL TERMINAL

PS4 260 KMRS4

313.3 KM

100 KM.14 KM. New ROW

RS5361 KM

PS5401 KMRS9

512.7 KM

SRIRAMPUR631 KMASSAM

BORDER

NJP TERMINAL832 KM

Existing mainline

RGP TERMINAL

197 KM ASSAM204 KM W.B.

112 KM

SCHEMATIC DIAGRAM OF PROPOSED NSPL ROUTE

The De-waxing and cleaning of 16” Loop Line of Oil India Limited pipeline is required to be carried out in view of joining the portion of loop line to the newly constructed product pipeline from Numaligarh Refinery to Siliguri Terminal.

– Pipe size of the line 16” (406mm)– Thickness of Pipe 7.9mm– Pipe API 5LX-46,52– Capacity of Product line 1.72 MMTPA

The job of cleaning and de-waxing was entrusted to CPTDC (China Petroleum Technology Development Corporation).

After preliminary ground work a piece of land of area 3200m2 outside RS-3 Kaziranga was rented to place equipment and machines accordingly.

A water storage pond of approximately 800m3 was constructed.

WATER STORAGE

PS-4 SekoniRS-3 Kaziranga

Loop Line

Main Line

Loop Line and Main line between RS3 and PS4

Steps involved in de-waxing and cleaning process

Pigging with different types of pigs with crude oil as medium

Sweeping of Crude oil

Hot water Pigging

Chemical Cleaning

Self Check

Chemical Cleaning

Acceptance Test

Equipment:

1) Compressors – Ingersoll Rand (2 no's) a) Capacity – 45m3/min, Pressure – 1.0 Mpab) Capacity – 30m3/min, Pressure – 2.4 Mpa

2) Water Pump – 4 no’s of various capacity3) Chemical dosing pump – 2 no’s4) Hot water boiler etc.

Equipment

Air Compressor

Water Pump

It was decided to start the work in the RS-3 Kaziranga to PS-4 Sekoni sector first.

The date of starting of the pigging operation was decided as 22.02.07.

General pigging process is decided to be carried out with combined and Bi-Di Pigs.

Pig Type :- a) Combined Pig (Brush, Cup & Plate)b) Bi - Di Pig

Size :- 105% of I.D of Pipei.e. 409.7mm ( Pipe I.D 390.2mm)

Pigs Used

Combined PigB.C.P(Brush, Cup & Plate)

Foam Pig

Bi – Di Pig

Pigging with different types of pigs with crude oil as medium

The first pig was launched at RS-3 Kaziranga for PS-4 Sekoni with a trekking instrument on 22.02.07.

Pig was tracked at various locations.Throughput in the line during pigging operation

was kept at 150Kls/Hr. Series of pigging operations were carried out

subsequently between RS-3 Kaziranga to PS-4 Sekoni from 22.2.07 to 08.04.07

Wax collected & other related information are given below

Cleaning Pigs

B.C.P Pig – Before & after Pigging

RS3-PS4 (Kaziranga-Sekoni) Crude Oil De-Waxing

Work Sheet

Times of Pigging:66 Wax quantity:20267KG

SL.NO. Type of Pig Launching Time Receiving Time Wax quantity/Kg

1. Cup Pig 22/02/07, 10:15 23/02.07, 18:10 1200

2. Cup Pig 24/02.07, 11:20 25.02.07, 18:30 1000

3. Bi-Di Pig 27.02.07, 11:45 01.03.07, 10:40 2000

4. Bi-Di-Pig 03.03.07, 08:44 04.03.07, 15:00 800

5 Bi-Di Pig 03.03.09, 16:15 04.03.07, 22:10 600

6. Bi-Di Pig 05.03.07, 08:40 06.03.07, 14:30 300

7 Brush Pig 05.03.07, 12:30 06.03.07, 19:30 700

8. Brush Pig 05.03.07, 16:30 06.03.07, 23:45 600

9. Brush Pig 08.03.07, 09:15 09.03.07, 16:30 900

10. Brush Pig 08.03.07, 13:00 09.03.07, 20:00 350

11. Brush Pig 08.03.07, 16:45 09.03.07, 22:30 300

12. Brush Pig 10.03.07, 08:45 11.03.07, 20:45 400

13. Brush Pig 10.03.07, 11:45 12.03.07, 02:10 400

14. Brush Pig 10.03.07, 14:45 12.03.07, 09:30 100

15. Brush Pig 10.03.07, 17:45 12.03.07, 10:50 75

16. Brush Pig 13.03.07, 08:45 14.03.07, 16:45 100

17. Brush Pig 13.03.07, 11:45 14.03.07, 18:50 400

18. Brush Pig 13.03.07, 14:45 14.03.07, 21:30 75

19. Brush Pig 13.03.07, 17:45 15.03.07, 01:15 2

SL.NO. Type of Pig Launching Time Receiving Time Wax quantity20. Brush Pig 15.03.07, 08:40 17.03.07, 11:45 300

21. Gauging Pig 15.03.07, 11:30 17.03.07, 13:00 0

22. Brush Pig 18.03.07, 08:45 19.03.07, 17:00 700

23. Brush Pig 18.03.07, 11:35 19.03.07, 20:30 40

24. Brush Pig 18.03.07, 14:30 19.03.07, 21:45 10

25. Brush Pig 18.03.07, 17:30 19.03.07, 23:45 120

26. Brush Pig 20.03.07, 08:45 21.03.07, 10:50 75

27. Brush Pig 20.03.07, 11:35 21.03.07, 13:40 20

28. Brush Pig 20.03.07, 14:25 21.03.07, 16:45 350

29. Brush Pig 20.03.07, 17:15 21.03.07, 19:25 120

30. Brush Pig 22.03.07, 08:35 23.03.07, 12:40 900

31. Brush Pig 22.03.07, 11:30 23.03.07, 17:30 10

32. Brush Pig 22.03.07, 14:30 23.03.07, 17:30 10

33. Brush Pig 22.03.07, 16:30 23.03.07, 20:10 10

34. Brush Pig 24.03.07, 08:30 25.03.07, 12:50 150

35. Brush Pig 24.03.07, 11:30 25.03.07, 16:25 30

36. Brush Pig 24.03.07, 14:00 25.03.07, 19:35 200

37. Brush Pig 24.03.07, 16:30 25.03.07, 22:40 500

38. Brush Pig 26.03.07, 08:50 27.03.07, 12:00 700

39. Brush Pig 26.03.07, 11:20 27.03.07, 15:00 0

40. Brush Pig 26.03.07, 13:50 27.03.07, 16:15 1041 Brush Pig 26.03.07, 16:20 27.03.07, 18:45 1042 Brush Pig 28.03.07, 8:35 29.03.07, 11:10 700

SL.NO. Type of Pig Launching Time Receiving Time Wax quantity/Kg

43. Brush Pig 28.03.07, 11:05 29.03.07, 14:00 100

44. Brush Pig 28.03.07, 13:30 29.03.07, 16:20 0

45. Brush Pig 28.03.07, 16:00 29.03.07, 19:00 0

46. Brush Pig 30.03.07, 08:40 31.03.07, 08:30 0

47. Brush Pig 30.03.07, 11:05 31.03.07, 11:05 250

48. Brush Pig 30.03.07, 13:30 31.03.07, 16:00 150

49. Brush Pig 30.03.07, 16:00 31.03.07, 18:00 200

50. Brush Pig 01.04.07, 08:35 02.04.07, 19:30 600

51. Brush Pig 01.04.07, 11:00 02.04.07, 21:55 5

52. Brush Pig 03.04.07, 09:15 04.04.07, 13:00 450

53. Brush Pig 03.04.07, 11:40 04.04.07, 15:20 350

54. Brush Pig 03.04.07, 14:10 04.04.07, 18:00 200

55. Brush Pig 03.04.07, 16:10 04.04.07, 20:00 450

56. Brush Pig 05.04.07, 08:55 06.04.07, 17:00 20

57. Brush Pig 05.04.07, 12:55 06.04.07, 21:00 350

58. Brush Pig 05.04.07, 16:55 07.04.07, 01:15 100

59. Brush Pig 05.04.07, 20:55 07.04.07, 04:55 350

60. Brush Pig 06.04.07, 00:55 07.04.07, 09:20 5

61. Brush Pig 06.04.07, 04:55 07.04.07, 13:00 400

62. Brush Pig 08.04.07, 08:10 09.04.07, 11:10 50

63. Brush Pig 08.04.07, 10:10 09.04.07, 12:45 250

64. Brush Pig 08.04.07, 12:10 09.04.07, 14:00 250

65. Brush Pig 08.04.07, 14:10 09.04.07, 15:40 400

66. Brush Pig 08.04.07, 16:10 10.04.07, 16:45 20

Same process started for the sector PS-4 Sekoni to RS-4 Ghani on 26.02.07

Wax collected in this sector is much more less than the previous sector.

Total quantity of wax collected in both the sector is around 26400Kgs approx.

Sweeping of crude oil

Very critical job.

Compressed air is used.

Safety precautions to be taken Static electricity / Earthing. Nitrogen Purging.

Arrangements of Equipment in Sweeping operation

Air Compressor --1

Air compressor --2

Water Pump

PS-4 SekoniRS-3 Kaziranga

Loop Line

Main Line

M/L is isolated from the Loop Line.M/L was kept pressurized at 35Kg/cm2.

The first pig was a combined pig, launched at 1210hrs.

The second pig was Bi-Di, launched at 1410hrsThe third pig was also Bi-Di, launched at 1610hrsThe fourth pig was also a Bi-Di launched at

1820hrs followed by 30Kl of water and again followed by a Bi-Di pig, and the whole train of pigs was driven by compressed air

Sweeping OperationCrude

Crude CrudeCrudeWater

-30 KlsAir

B.C.P Pig

Bi – Di Pig

Bi – Di Pig

Bi – Di Pig

Bi – Di Pig

The oil from the loop line was taken into the balance tank at PS-4 and normal pumping from PS-4 Sekoni was continued.

The fourth pig which was the last pig in contact with the crude oil was received on 9.4.07 at 1855 hrs and sweeping operation completed.

The line is immediately isolated from all the crude oil connections.

In PS4 – RS4 sector the oil column in front of the sweeping pig was very long which was from PS-4 Sekoni to PS-5 Noonmati of 140Km long.

The length of the oil column to be swept is only 53Km.

After completing sweeping operation in both the sectors, multiple pigging with air started and considerable amount of cleaning is achieved.

Sweeping process(PS-4 Sekoni to RS-4 Ghani)

PS-4 Sekoni

M/L

L/L

M/L under Pressure

RS-4 Ghani

Loop Line between PS4 Sekoni & RS4 Ghani

Hot water Pigging

Decided to carry out hot water pigging.Hot water plug of 200mtrs was driven

between one combination pig and a Bi-Di pig with the help of air.

The water temperature at the inlet is 80’CThis process continued for a few days and

foam pigs were also driven along with air until certain level of cleaning is achieved.

HOT WATER

16” Loop Line under cleaning

4” Line

Hot Water

Arrangement for Hot Water Pigging

Chemical CleaningChemical mixed with H.S.D in a ratio of 1:12 is

used.The H.S.D and the chemical mixture is plugged

between two pigs, of which one is a combination pig and other a Bi-Di pig, and the plug is followed by 30Kl of water.

The whole train is driven by compressed air.Initially 12Kl of H.S.D was mixed with 1Kl of

chemical.

AirAir

H.S.D (12Kl) + CHEMICAL(1Kl)

WATER

30 Kl

B.C.P Pig

Bi – Di Pig

Bi – Di Pig

Chemical Cleaning

Same procedure was followed for the other sector also.

After cleaning with chemical a self check was required to be carried out and finally 200mtrs of H.S.D was plugged between 350mtrs and 250mtrs of water with separating pigs and the train was driven between RS-3 Kaziranga and PS-4 Sekoni as shown in the figure.

Self Check

water H.S.D water

350 m200 m 200 m

B.C.P Pig

B.C.P Pig

B.C.P Pig

B.C.P Pig

Foam Pig

Foam Pig

Self Check

AIRAIRAir

The above process was also carried out in the other sector and concentration of chemical required is determined to 1:12 only, and the chemical cleaning process is decided to be taken up once again.

The final acceptance test of the cleaning process is decided to be taken up after self check and the total cleaning process.

The process is carried out as follows

Acceptance test

Water H.S.D Water

Bi – Di Pig

Bi – Di Pig

Bi – Di Pig

Bi – Di Pig

200 m 300 m 100 m

AirAir

H.S.D – Euro III was used for testing in the line.

When H.S.D reached PS-4 Sekoni various samples were taken in presence of OIL, NRL and CPTDC representatives and tested for colour.

For conducting the process of colour test, officers of chemical department of all the three parties carried out the test with respect to the colour code.

The colour code was established by contaminating crude oil and wax with Euro III – H.S.D in the laboratory and they were observed in testing machine.

The colour code of Euro III – H.S.D was taken as to be “0”.

Colour code chart

Contaminated Sample (ppm) Color code with crude Color code with wax

10 0 0

20 0 0

50 1 1

100 2 2

200 3 4

500 6-7 7

1000 9-10 11

5000 17 18

10000 22 28

Samples collected during Acceptance test

PS4 – RS4 Sample RS3 – PS4 Sample

It was found in the laboratory that sample with colour code 7 (i.e. up to 500ppm contamination)was within acceptable limit.

The following results of colour code were found in the sectors RS3 – PS4 & PS4 – RS4.– RS3 to PS4 0 –1– PS4 to RS4 4 – 5

Precaution taken in respect of safety

While carrying out sweeping operation with the help of air, nitrogen was purged into the receiving trap at both the location i.e. PS4 and RS4 in a regulated manner.

Utmost precautions were taken when sweeping pig was near to the receiving trap to avoid any collision of pig head with the barrel door.

Cushioning materials were also placed near the door of the receiving trap.

The line was completely earthed in three places to discharge any static electricity that may be generated due to numerous numbers of pigging operations.

Flame proof equipment were only used inside the repeater stations and pump stations to avoid any incidents.

Precaution taken in respect of Environment

To avoid any pollution, spill of oil is totally restricted in Pump Stations and Repeater Stations.

Wax and other materials were dumped in a location made with concrete and poly-ethylene lined sheet.

Water and other liquids coming out of the line is kept reserved in a poly-ethylene lined concrete walled pond made at RS-4 Ghani.

An effluent treatment plant (portable) was constructed by the contractor to treat the effluent before disposal which is again tested to avoid any pollution and it was kept under 10mg/Ltr.

H.S.D and other chemicals were recycled and reused for the other sectors.

Portable Effluent treatment Plant

Benefits:

Construction of a new pipeline of 212Kms long would have cost us Rs 250 crores but the cost of cleaning and de-waxing of existing line was only Rs 27 crores.

Construction of pipeline inside Kaziranga sanctuary would have been a difficult job in view of the environmental policy of the Government.

THANK YOU