sand cleaning statfjord c field test stavanger 18 – 19 january 2006 henrik dannström, mator as
TRANSCRIPT
SAND CLEANING STATFJORD C FIELD TESTSAND CLEANING STATFJORD C FIELD TEST
Stavanger 18 – 19 January 2006Stavanger 18 – 19 January 2006Henrik Dannström, MATOR ASHenrik Dannström, MATOR AS
CURRENT PRACTICE ON THE NORWEGIAN SHELFCURRENT PRACTICE ON THE NORWEGIAN SHELF
Solids are normally handled in dedicated treatment units.
In most cases jetting water and associated solids are treated separate from main produced water stream.
Solids are reinjected, treated to achieve discharge quality or sent onshore for disposal.
BACKGROUNDBACKGROUND
Discharge quality governed by
REGULATIONS RELATING TO CONDUCT OF ACTIVITIES IN THE PETROLEUM ACTIVITIES (THE ACTIVITIES REGULATIONS)
Section 59 discharge of cuttings, sand and solid particles
Cuttings from drilling and well activities, sand and other solid particles shall not be discharged to sea if the oil content of formation oil, other oil or base fluid in organic drilling fluid is more than ten grams per kilogram of dry matter.
Dedicated sand treatment not available on Statfjord C. Statoil therefore wanted in 2005 to investigate sand treatment
methods utilising existing equipment (Flash Tank CD2015).
CONCEPT STAGESCONCEPT STAGES
1. Theoretical evaluation optional cleaning methods
(mechanical, steam, chemical) suitability of CD2015 for selected
method (pressure, temperature, materials, instrumentation etc)
sampling and analysing methods
→ Decision to investigate condensate wash
2. Laboratory test washing of sand with condensate
→ Decision to proceed with field test
TEST SET-UP, PILOT SCALETEST SET-UP, PILOT SCALE
Process and test separator jetting water and –sand routed batchwise in to CD2015. Excess water drained between jettings.
TEST CONDITIONS, PILOT SCALETEST CONDITIONS, PILOT SCALE
Volumetric flow rate to ensure fluidisation of sand in one of three jetting sections
Fluidisation factor (F) to be higher than 0.0011)
gDL
dpnF
ls
)(
22
2
1) Tippets, R Priestman G ”Liquid Jet Fluidisation and Solids Wash Out”
TEST CONDITIONS, PILOT SCALETEST CONDITIONS, PILOT SCALE
Operating pressure to ensure liquid phase condensate in wash section
TEST CONDITIONS, PILOT SCALETEST CONDITIONS, PILOT SCALE
Mixing of condensate and sand / water
- in–line mixer used Condensate flow rate to fit purpose
- tested with 0.1 – 0.2 vol-% of water flow rate Recirculation
- until desired oil-on-sand concentration achieved
Disposal of hydrocarbons
- flashing / disposal through flare and skimming to reclaimed oil sump
TEST SET-UP, PILOT SCALETEST SET-UP, PILOT SCALE
ANALYZING METHODSANALYZING METHODS
Sampling
Concentration and analysis
Filtering 1.2 µm / 5.0 µm
Weighing (correction for OiW) – washing – re-weighing
Method accurate down to 0.2 wt%.
Method to be modified for floating installations
Retorte – accuracy down to 0.5 – 1.0 wt%, requires larger sample volumes
IR / Infracal for OiW
TEST RESULTS, PILOT SCALETEST RESULTS, PILOT SCALE
Inlet separator sand.Condensate 0,1 vol-%
0,0
20,0
40,0
60,0
80,0
100,0
120,0
140,0
160,0
180,0
00:00 00:14 00:28 00:43 00:57 01:12 01:26 01:40 01:55 02:09
Runtime (hr:min)
(mg
/l)
-
10,0
20,0
30,0
40,0
50,0
60,0
(%)
Sand+oil (mg/l)
Sand (mg/l)
Oil [wt-%]
Start kondensat
TEST RESULTS, PILOT SCALETEST RESULTS, PILOT SCALE
Test separator + CD 2072 sand.Condensate 0,2 vol-%
0,0
20,0
40,0
60,0
80,0
100,0
120,0
140,0
160,0
180,0
00:00 00:14 00:28 00:43 00:57 01:12 01:26
Runtime (hr:min)
(mg
/l)
-
10,0
20,0
30,0
40,0
50,0
60,0
(%)
Sand+oil (mg/l)
Sand (mg/l)
Oil [wt-%]
Start condensate
TEST RESULTS, PILOT SCALETEST RESULTS, PILOT SCALE
POSITIVE: Promising results in terms of cleaning
efficiency, although 10 g/kg not was achieved
CD2015 well suited for purpose Full scale test may easily be carried out
based on same principle
NEGATIVE: Mechanical failure (leakage) led to
modifications on site and reduced capacity
Reduced sand concentration over time
CONCLUSION:
Results promising enough to proceed with full scale field test
TEST SET-UP, FULL SCALETEST SET-UP, FULL SCALE
Major changes to pilot test:
- all three jetting sections utilised
- larger flow rate (larger pump, hoses, lines, valves)
- more instrumentation
- longer test period
- more analysing equipment
TEST SET-UP, FULL SCALETEST SET-UP, FULL SCALE
Pump
210 m3/h
10 barg
Condensate feed
to in-line mixer
TEST CONDITIONS, FULL SCALETEST CONDITIONS, FULL SCALE
Volumetric flow rate to ensure fluidisation of all sand in vessel
Tie-in such that all water and sand in vessel are circulated
Operating pressure to ensure liquid phase condensate in wash section
Mixing of condensate and sand / water. In-line mixer used.
Water level 50% - 70% of vessel height Condensate flow rate to fit purpose Recirculation Disposal of hydrocarbons
TEST RESULTS, FULL SCALETEST RESULTS, FULL SCALE
Results from 1:st sand batch circulation
Test 1Condensate 0,1 - 0,15 vol-%
33
8 100
910 18
75
9777
136
95
1619 13 11
148
0
20
40
60
80
100
120
140
160
180
200
00:00 02:00 04:00 06:00 08:00 10:00 12:00 14:00 16:00 18:00 20:00
Runtime (hr:min)
Oil
on
san
d (
g/k
g)
-10
40
90
140
190
240
Oil
in
wat
er (
mg
/l)
Oil on sand
OiW
Start condensate
Stop condensateSkimming of oil
TEST RESULTS, FULL SCALETEST RESULTS, FULL SCALE
Results from 2:nd sand batch circulation
Test 2Condensate 0,1 - 0,15 vol-%
32
75
7
61
11 20
0
20
40
60
80
100
120
140
160
180
200
00:00 01:00 02:00 03:00 04:00
Runtime (hr:min)
Oil
on
san
d (
g/k
g)
0
20
40
60
80
100
120
140
160
180
200
Oil
in
wat
er (
mg
/l)
Oil on sand
OiW
Start condensate
TEST RESULTS, FULL SCALETEST RESULTS, FULL SCALE
Results from flow regime test
Clampon sand data
0
0,5
1
1,5
2
2,5
15:00 16:00 17:00 18:00
Time
Le
ve
l
Sand rate (g/s)CloseOutlet 1,2
CloseOutlet 3
CloseOutlet 4
Stop
Open Outlet 4
Open Outlet 3
Open Outlet 2
Open Outlet 1
CloseInlet 3
TEST RESULTS, FULL SCALETEST RESULTS, FULL SCALE
SUMMARY
Demonstrated ability to achieve discharge quality for oil wetted sand by means of condensate washing.
Associated water quality well below discharge requirements.
Overall condensate consumption to achieve cleaning of 1 week of accumulated jetting solids approximately 1 m3, of which 20 - 30% reclaimed.
BATCH PROCESS REQUIREMENTSBATCH PROCESS REQUIREMENTS
Vessel with holding capacity for separator / process vessel jetting inventory
Pumparound system for vessel inventory, with pump discharge pressure above condensate flash point
Flow capacity and internal distribution arrangement to ensure fluidisation of solids
Suitable mixer and choke Condensate with appropriate qualities Means for discharge of flashed and gravity
separated hydrocarbons
CONCLUSIONCONCLUSION
Client objective of finding alternative means of solids treatment identified.
Concept is oil extraction from sand using condensate. This can be achieved in several configurations. One batch configuration found suitable for Statfjord C.
Technology qualification next step towards implementation as permanent installation.
Implementation of concept on other facilities subject to feasibility evaluation.