Determination of Fluid Loss Screen Life

Determination of Fluid Loss Screen Life

API SC 10Scott Jennings

2012 Exploration and Production Standards Conference on Oilfield

Equipment and Materials

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Current Situation

• Currently, no requirement for replacing fluid loss screen.

• Sec. 10 Static fluid-loss tests

• Problems noticed when testing FLAs for acceptance criteria & comparing FL data with SC.

• API spec for Blade Wear:

• Discard if mass loss >10 %

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Lab – Lab Results

• Variables running the test are:

• Technician – accuracy of performing FL test

• Pressure delivered

• Screen

• Visibility

• Weight

• Flow rate

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Lab – Lab Results

• Fluid loss tests that do not run a full 30 min have a potential error that becomes greater as the length of the test becomes shorter. Fluid-loss tests that run the full 30 min typically show 5 % variability. Tests that run less than 5 min. can have a variability of more than 30 %.

Average of 11 tests

• ARAMCO vs SC A = 15.3%

• ARAMCO vs SC B = 45.8%

• ARAMCO vs SC C = (-13.6%)

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Initial Findings• Labs discard screens at technician discretion (Vis.).

• Unattended test lead to higher degree of uncertainty.

• Tech. around but not totally on top of test.

• N2 source should have a defined min. starting supply pressure for the static test.

• regulated pressure down to 1000 psi diff.

• 1200 psi on stirred FL apparatus

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Flow Rate Determination Procedure (New Screen)

1. Weigh FL screen dry

2. Soak in water for 2 mins.

3. Assemble FL cell

4. Fill cell with 165 gr. Water SG=1.00

5. Open drain valve and start clock simultaneously

6. Stop clock and record time when water level has left the inside of the cell.

7. Dry with compressed air

8. Repeat steps 4-7 four more times

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Initial Study• 26 new screens weighed (metal backed)

Ave. 21.99 gr.

High 22.24 gr.

Low 21.52 gr

• 5 screens selected for water flow test

• Water gravity flow test

165 grams of water flow through cell (SG-1.00)

5 test times recorded (sec)

Rates calculated (ml/sec)

Best match to average was selected (screen no. 5)

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FL Cell

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Water Test

New Fluid Loss ScreensTime for 165 ml to pass through 325 mesh screen

1 2 3 4 5 Ave Rate

Time (sec) ml/sec

41.4 39.1 41.5 41.7 40.2 40.78 4.05

42.5 40.8 40 42.1 41.3 41.34 3.99 H

39.7 42.1 42.2 41.9 40.5 41.28 4.00

41.3 39.5 40.2 41.5 39.6 40.42 4.08 L

40.3 42.4 40.8 39.9 41.7 41.02 4.02 A

Screen Weight Average time for all 40.97 4.03

H -Heavy L -Light A -Average

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20 FL Tests Performed•10 slurries selected 115-283 cc’s/30 mins.

Screen weighed before FL test

Water Flow Rate determined before FL test

2 tests made 30 mins.

•Same 10 slurries repeated 120-215 cc’s/30 mins.

Screen weight increased from 22.01 to 22.08 gr.

4 tests made 30 mins.

•Can continue if SC 10 is interested.

New FL Screen no. 5 Selected

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•20 tests ran

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Flow Rate Determination Procedure (Used Screen)

1. Weigh FL screen dry

2. Soak in water for 2 mins.

3. Assemble FL cell

4. Fill cell with 165 gr. Water SG=1.00

5. Open drain valve and start clock simultaneously

6. Stop clock and record time when water level has left the inside of the cell.

7. Dry with compressed air

8. Repeat steps 4-7 two more times

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• 13 used screens weighed (metal backed)

Ave. 20.33 gr.

High 22.59 gr.

Low 19.31 gr.

• 5 screens selected for water flow test

Weight (high and low)

Visibility (best and worst)

• Water gravity flow test

165 grams of water flow through cell (SG-1.00)

3 test times recorded (sec)

Rates calculated (ml/sec)

Used FL Screens

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Water Test Used Screens

Used Fluid Loss ScreensWeight

Screen Grams Visibility 1 2 3 Ave. Rate

No. Time (sec) ml/sec

1 19.67 Worst 300+ 82.7 ml left   300.00 <0.55

5 19.31 Low 93.6 92 105.4 97.00 1.70

8 20.52 72.3 69.7 72.8 71.60 2.30

11 22.59 High 48.5 50.3 47.1 48.63 3.39

13 20.31 Best 49.7 44.7 49.8 48.07 3.43

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Future Work

Any Interest to Pursue?

21.99 New 4.03