003.0 Surface Sampling Operating Procedures

SURFACE SAMPLING - GENERAL GUIDELINES REF: OP 019

R E V: 03

DATE:

26 April 1999

PAGE 1 of 9

1.0

GENERAL

GUIDELINES

1.1

Before sampling commences, the Client's Test Engineer must verbally confirm that separator conditions are stable and suitable for sampling.

1.2

Chemical injection upstream of the separator must be stopped to avoid sample contamination (delay between cessation of chemical injection and commencement of sampling must be of sufficient length to ensure the separator has been purged). If flowing conditions dictate that chemical injection must continue during sampling, injection rates, injection points and injected chemicals must be recorded on the sample data sheets.

1.3

The well test service company's Shift Supervisor must be aware of the sampling operation before sampling commences.

1.4

Sample datasheets must be completed with the correct data. The Client's Test Engineer should confirm verbally that the correct information has been used.

1.5

Pressurised samples should be labelled as follows:- The box should have a plasticised label attached to the RHS handle. - The bottle should have a plasticised label attached to the top protector. - The green status tag should be removed. - A completed sample datasheet should be placed inside the box in a poly self-seal bag. - The correct hazard diamond labels should be stuck on the top of the box and on the sample bottle.

1.6

Atmospheric samples should be labelled as follows:- The container should be marked up with sample details (sample no, sample nature, sample point, well, test number, date/time, Client, installation) using a paint marker or similar indelible pen. - A completed self adhesive sample label should be stuck on the container, and if the container has a handle, a plasticised label should be attached. - Drums which are likely to be stored in the open should have sample and well number scratched on. - The correct hazard diamond labels should be stuck on the sample container. The triplication of details is necessary as labels, paint, etc can all come off, rendering the sample unidentifiable and useless.

1.7

When filling atmospheric containers with crude, leave a 10% space for expansion inside the container. Allow the sample to de-gas for as long as possible before screwing the lid on, as agitation during shipping causes evolution of gas which can rupture the container. Do not allow rainwater, spray, etc to contaminate the sample while it is de-gassing.

1.8

Generally, atmospheric oil samples should be taken in metal containers and atmospheric water samples into plastic or glass containers. Metal containers should be IATA approved. (UN number on the can).

1.9

Do not use third party gauges for sampling as they may have been used for mercury displacement sampling and may contaminate the sample (in the case of gas sampling the introduction of mercury will damage the sample cylinder).

Warning: The controlled source document of this procedure is stored on Oilphase homepage (http://www.aberdeen.oilphase.slb.com). Any paper version of this procedure is uncontrolled and should be compared with the source document at time of use to ensure it is up-to-date. PREPARED BY:

RS

VERIFIED BY:

DG

A P P R O V E D B Y : GD

SURFACE SAMPLING - GENERAL GUIDELINES REF: OP 019

R E V: 03

DATE:

26 April 1999

PAGE 2 of 9

1.10

Separator oil sampling point should be midstream on the oil line, upstream of the meters. The oil level sight glass should be used only if there are no suitable sampling points on the oil line. The sight glass must be purged and refilled several times and the check valve set in the "open" position. Avoid emptying the sight glass while sampling (which allows the sample bottle to fill with gas).

1.11

Separator gas sampling point should be the highest available point on the separator gas outlet line, upstream of the orifice meter. A sampling point on the underside of the gas outlet line should be avoided however, as liquid carry over may if present be taken into the gas sample bottle.

1.12

Separator pressurised oil and gas sampling should be carried out at the same time where the samples are to be used for recombination. This ensures that both samples are taken under the same separator conditions and can be matched with each other.

2.0

LIQUID SURFACE SAMPLING using the Oilphase Conventional Bottle

2.1

Place sample bottle in stand (Item 9) using bottle collar (Item 7). Fit top oil manifold (item 5), bottom manifold (item 4) and connect pump (Item 11) to the bottom manifold bleed valve V4. Open CSB V3, CSB V1 and V4 and pressure up bottle to oil line pressure ie separator pressure. See Figure 1.

2.2

Close V4 and disconnect pump.

2.3

Connect liner (item 3) between top manifold and sampling point valve V1.

2.4

Ensure all valves are closed.

2.5

Pressure up liner by opening valve V1.

2.6

Open V2 and purge liner by opening V3. Purge at least five liner volumes. Close V3.

2.7

Open CSB V2 and gently open CSB V1. Purge 2 to 3 liner volumes across piston in sample bottle through 1/ 4" slimline autoclave elbow (Item 6) to CSB V1 port.

2.8

Close CSB V1. Remove 1/4" slimline autoclave elbow and plug CSB V1 port. Proceed to take sample by gently opening V4 and allowing sample to displace the water/glycol mixture into the measuring cylinder. Record time for commencing sampling. Observe sight glass level to avoid drawing gas into the sample bottle.

2.9

Maintain separator pressure on bottom manifold gauge at all times and to avoid sample "flash". Use V4 to control water/glycol displacement and bottle pressure.

2.10

After displacement of 600 cc of water/glycol V4 should be closed followed by CSB V2. check that CSB V1 and V4 are closed, CSB V3 is open.

2.11

Open V4 and remove a further 60 cc of water/glycol to create a 10% gas cap for shipping. CAUTION: Care should be taken not to allow the piston to bottom out as it will become unbalanced.

2.12

Record the final pressure, the ambient temperature and the end time of sampling. Close CSB V3 and open V4 to bleed bottom manifold. Close V1, open V3 and bleed down liner pressure.

2.13

Disconnect the liner and both manifolds. Plug CSB V1, CSB V2 and CSB V3 ports. Check bottle for leaks, label the bottle and box and complete a surface sample datasheet. When the sampling report is printed, print an additional copy of the datasheets to accompany the sample.

SURFACE SAMPLING - GENERAL GUIDELINES REF: OP 019

R E V: 03

DATE:

26 April 1999

PAGE 3 of 9

Figure 1. Liquid Surface Sampling using the Conventional Sample Bottle (CSB)

Index Item

Description

Reference

Qty

1 2 3 4 5 6 7 8 9 10 11 12 13

1/2" NPT (m) x 1/4" JIC (m) adapter 1/4" NPT (m) x 1/4" JIC (m) adapter 100K 1/4" JIC synflex liner (8 ft) Oil manifold (bottom) Oil manifold (top) 1/4" SL autoclave 90 purge nipple Sample bottle collar 19 mm box spanner Bottle stand Test gauge (1,500 psig) Enerpac hand pump Measuring cylinder (1 Litre) Conventional sample bottle (CSB)

QR0900 QR0899 QR0989 AR0886 AR0887 AR0892 QR0501 AT0157 QR0893 QR0904 QT0113 QT0143 PR0767

1 1 2 1 1 1 1 1 1 1 1 1 1

SURFACE SAMPLING - GENERAL GUIDELINES REF: OP 019

R E V: 03

DATE:

26 April 1999

PAGE 4 of 9

3.0

LIQUID SURFACE SAMPLING using the Oilphase Single-phase Sample Bottle

3.1

Check Sample Bottle Status Form (F-153) Under normal circumstances bottle will be shipped full of 50/50 glycol/water mix.

3.2

Place sample bottle in stand. See Figure 2.

Figure 2. Monophasic Liquid Surface Sampling using the Single-phase Sample Bottle (SSB)

Item

Description

Reference

Qty

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19

1/2" NPT (m) x 1/4" SL Autoclave (m) adapter 1/4" NPT (m) x 1/4" SL Autoclave (m) adapter 10K 1/4" JIC synflex liner (8 ft) Oil manifold (bottom) Oil manifold (top) 1/4" SL autoclave 90 purge nipple Sample bottle collar 19 mm box spanner Bottle stand Test gauge (10,000 psig) Air operated glycol/water pump Measuring cylinder (1 Litre) Conventional sample bottle (CSB) Single-phase sample bottle (SSB) 1/4" SL autoclave polyflex liner 8 ft 1/4" SL Autoclave (m) x 1/4" JIC (m) adapter 1/4" SL autoclave (m) x 1/4" JIC (m) adapter OFN regulator c/w 1/4" JIC (m) adapter OFN bottle spanner

QR0906 QR0526 QR0898 AR0888 AR0889 AR0892 QR0501 AT0157 QR0893 QR0902 N/A QT0143 PR0767 PR0768 QR0897 QR0131 AR0901 QT0138 QT0174

1 1 1 1 1 1 2 2 2 1 1 1 1 1 3 4 1 1 1

SURFACE SAMPLING - GENERAL GUIDELINES REF: OP 019

R E V: 03

DATE:

26 April 1999

PAGE 5 of 9

3.3

Fit upper Item 5 and lower item 4 manifolds. Note Sample bottle valves are operated using 19 mm box spanner. (Item 8).

3.4

Connect glycol/water pump to the lower manifold bleed valve V4. Flush manifold with glycol/ water prior to tightening connection to bottle.

3.5

Open V4, SSB V3, SSB V1 and pressure up lower manifold and below bottle piston to wellhead pressure.

3.6

Close V4 and remove pump.

3.7

Connect liner (Item 15) between upper manifold and sampling point V1.

3.8

Ensure all valves are closed (except for SSB V3).

3.9

Pressure up liner by opening valve on sampling point V1.

3.10

Purge line through bleed valve V3, then open SSB V2 and purge across sample bottle piston by opening SSB V1.

3.11

Close SSB V1. Note: If oil is extremely viscous glycol/water pressure below piston may have to be reduced in order to allow flow across the top of the piston.

3.12

Proceed to take sample by gently opening lower bleed valve and allowing sample to displace water into measuring cylinder.

3.13

Maintain wellhead pressure on gauge at all times to avoid sample "flash" using V4 to control pressure and water flow.

3.14

A 600 cc sample should be taken then V4 should be closed, followed by SSB V2.

3.15

Bleed off line between upper manifold and sample point, disconnect liner.

3.16

Connect regulated oxygen free nitrogen (OFN) supply to valve CSB V1.

3.17

Connect glycol/water pump to valve CSB V3.

3.18

Connect OFN liner (Item 15) between CSB V2 and SSB V4 (port marked N).

3.19

Purge OFN line by opening valves CSB V1, CSB V2, SSB V4 and loosening liner connection at SSB V4. Tighten liner connection to SSB V4.

3.20

Regulate OFN supply to 200 psig and fill booster bottle slowly by opening valve CSB V3 and glycol/water pump bleed valve.

3.21

Increase OFN pressure to maximum bottle pressure (max pressure of full cylinder is 2,000 - 3,000 psig).

3.22

Close CSB V1. Bleed OFN and rig down liner.

3.23

Ensure valve SSB V4 is open, boost OFN pressure using glycol/water pump to sample pressure.

3.24

Using glycol/water pump regulator set at least 500 psi above sample pressure, slowly open valve V4 and remove a further 60 cc of glycol/water in order to create a nitrogen gas cap for shipping.

3.25

Close all sample bottle valves, bleed off pressure in manifolds prior to removing. Plug all valves.

SURFACE SAMPLING - GENERAL GUIDELINES REF: OP 019

R E V: 03

DATE:

26 April 1999

PAGE 6 of 9

3.26

Label the sample bottle and box, and complete a sample datasheet. A copy of the datasheet must accompany the bottle.

4.0

GAS SAMPLING

4.1

Check bottle has been evacuated to less than 1.0 mbar or less than 10 mmHg.

4.2

Connect gas manifold (Item 4) to top valve on bottle, GSB V1 with suitable test gauge (separator pressure >33%,