TESTING OF AH ALLIBURTON

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					         TESTING OF A HALLIBURTON SSSV ON
                  OCEANIC BTC 491
                 @ 176°c & 15 000 psi


Report By:         Simon McManus
                   Technical Services Manager
Date:              25:7:97




         Wm. Canning Ltd. Marston Bentley Division, Wigan WN2 1JR UK. Tel: 01942 824242 Fax 01942 826653

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             TESTING OF A HALLIBURTON SSSV ON OCEANIC BTC 491
                             @ 176°c & 15 000 psi




                                                SUMMARY

The objective was to qualify Oceanic BTC 491, a synthetic hydrocarbon fluid, for use at
176°c and 15 000psi.

The testing was done by BHR Cranfield, a specialist hydraulic test house, using a purpose
built rig and a Halliburton Valve. The test period was 3 months during which the valve
was cycled 250 times.

At the end of this time the condition of the valve was examined by the manufacturer, and
the oil by a specialist consulting laboratory.

The oil was found to be in good condition. There was some darkening, but this is to be
expected as the antioxidant is consumed by reacting with oxygen initially present. There
was no significant build up of solids, and the viscosity, corrosion inhibition and lubricity
were essentially unchanged.

The valve was in generally good condition with no degradation of threads or metal to
metal seals. There was also no detrimental effect of the fluid on elastomeric seals.




         Wm. Canning Ltd. Marston Bentley Division, Wigan WN2 1JR UK. Tel: 01942 824242 Fax 01942 826653

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             TESTING OF A HALLIBURTON SSSV ON OCEANIC BTC 491
                             @ 176°c & 15 000 psi

Introduction

This testing was carried out to see if a sub surface safety valve (SSSV) could be operated
reliably at 176°c and 15,000 psi. The valve used was a Halliburton valve, which has been
specified for high temperatures. The fluid used was Oceanic BTC 491 high temperature
sub-sea control fluid supplied by Wm. Canning.

Summary of Method

                                                    The test entailed valve operation at temperature
                                                    with a soak time between each set of valve
                                                    cycles.


                                                    Test temperature:                   176°c
                                                    Control Fluid Pressure:             15 000psi
                                                    Valve Back Pressure (N2)            10 000psi
                                                    Valve cycles at start-up            50
                                                    Soak period                         1 month
                                                    Valve cycles per interval           66
                                                    Number of soak periods              3
                                                    Total period of test                3 months
                                                    Valve cycles at end                 68
                                                    Total Valve Cycles                  250


                                                    The test rig used for this work was a purpose
                                                    built facility at BHR Cranfield (pictured left).
                                                    This equipment was used to assess valves and
fluids for a major joint industry project.

Halliburton examined the Valve before and after test.

Fluid samples were taken from the system every month before valve cycling. An
independent test laboratory, Wearcheck, inspected these samples. The Wm Canning
results can be found later in this section.




         Wm. Canning Ltd. Marston Bentley Division, Wigan WN2 1JR UK. Tel: 01942 824242 Fax 01942 826653

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Comparative results on the fluid were obtained at the start and end of the test. These tests
included:

Acid number
Cleanliness levels
Major additive levels
Infrared traces.

Summary of Results

i.        Valve Cycling and Operation

From examination of the BHR test report we can see there were no functioning problems
encountered due to fluid or valve operation. “Each one of the above tests (valve cycling)
were completed without any apparent problems or leakage occurring”.

ii.       Valve Condition

From the Halliburton report on the valve condition after test we can see that the valve
was in generally good condition with no degradation of threads or metal to metal seals.
Elastomer seals were also unaffected by the fluid.

iii.      Fluid Analysis

General Properties

                                         Fresh Oceanic BTC 491                Oceanic BTC 491 after 3
                                       sample taken from BHR test              months @ 176°c and
                                          rig before temperature             15,000 psi in the BHR test
                                                application                              rig.
           Appearance                        Clear straw fluid                 Clear dark straw fluid
       Acidity mgm.KOH/g                             1.6                                 2.5
       Viscosity @ 40°c cS                          10.9                                10.2
            ISO Class                              18/15                               18/13
          ppm Calcium                               168                                  162
        ppm Phosphorus                              684                                  665
            ppm Zinc                                912                                  796




         Wm. Canning Ltd. Marston Bentley Division, Wigan WN2 1JR UK. Tel: 01942 824242 Fax 01942 826653

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Elemental analysis

The following graph shows how the elements within the fluid varied form month to
month during the test. It should be noted that the points on the graph have been at the
time of sampling and may not correspond to the time of contamination.

The final sample was taken from the drained fluid at the end of the test. The one and two

                                                       Elem ent Levels in BTC 491 BHR Testing                               Ca
                                                                                                                            P
                        1200                                                                                                Mg
                                                             1127
                                                                                                                            Zn
                        1000
                                                                                            931
                               912                       818
    Element Level ppm




                        800                                                                                           796
                                                                                            710
                               684                                                                                    665
                        600


                        400
                                                         254
                                   168                                                      192
                        200                                                                                           162
                                                             57
                                   0
                                                                                            29                        13
                          0
                               0          0.5            1               1.5            2          2.5            3
                                                                    Months on Test


month samples were taken via a sample port and were relatively small samples.

Conclusions

From the above results we can see there has been little change in the fluid properties over
the test period. The slight darkening of the fluid will be due to the anti-oxidant doing its
job and soaking up the unwanted dissolved oxygen.

One point to note from the independent Wearcheck information is that the additive levels
in the fluid rose after the one-month samples. These levels were still high after two
months but had come down to an acceptable level at the end of the test.

I feel this is due to some solids from previous testing settling in the sample ports or being
freed at temperature. This would account for the cloudy look to the first samples taken, as
the samples were only small (20ml) they would be more affected by contamination.
Sampling of the 491 during this test has flushed these ports and removed the debris. I am
confident that the material did not come from the Oceanic BTC 491 as magnesium was
detected which was not present in the control fluid at the start of the test and should not
be present.


                        Wm. Canning Ltd. Marston Bentley Division, Wigan WN2 1JR UK. Tel: 01942 824242 Fax 01942 826653

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The slight increase in contamination class is not unexpected, valve cycling will create
some debris. There is no fluid flowing through the valve, this will cause the
contamination class to build up. Some of the contamination will be due to solid material
from previous tests and the collection of fluid.




         Wm. Canning Ltd. Marston Bentley Division, Wigan WN2 1JR UK. Tel: 01942 824242 Fax 01942 826653

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