using locas software to predict the long-term behavior of salt caverns
using locas software to predict the long-term behavior of salt caverns
using locas software to predict the long-term behavior of salt caverns
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USING LOCAS SOFTWARE<br />
TO PREDICT<br />
THE LONG-TERM BEHAVIOR<br />
OF SALT CAVERNS<br />
Technical Class<br />
SMRI Fall Meeting – Leipzig, Germany<br />
Oc<strong>to</strong>ber 3, 2010<br />
1<br />
OUTLINE<br />
• Introduction – LOCAS main features<br />
• Example <strong>of</strong> application: cavern abandonment<br />
• Conclusions<br />
2<br />
1
QUICK INTRODUCTION<br />
WHAT IS LOCAS?<br />
• A 2D axisymetrical Finite Element code<br />
• Af fully coupled dThermo-Hydro-Mechanical h code<br />
• A powerful —but user-friendly— Windows ® <strong>s<strong>of</strong>tware</strong><br />
WHAT IS IT FOR?<br />
• Study <strong>of</strong> liquid-filled or gas-filled <strong>salt</strong> <strong>caverns</strong><br />
• Short-<strong>term</strong> and <strong>long</strong>-<strong>term</strong> <strong>behavior</strong> <strong>of</strong> <strong>caverns</strong><br />
Examples <strong>of</strong> applications:<br />
• Stability <strong>of</strong> cavern at min/max pressure, cycling<br />
• Analysis <strong>of</strong> Mechanical Integrity Tests<br />
• Abandonment <strong>of</strong> <strong>salt</strong> <strong>caverns</strong><br />
3<br />
EXAMPLE OF APPLICATION<br />
CAVERN ABANDONMENT<br />
Carresse SPR2 cavern test supported by SMRI<br />
300 m<br />
9000 m 3<br />
4<br />
2
KEY POINTS IN THE ANALYSIS OF AN ABANDONMENT TEST<br />
• PRELIMINARY TASKS<br />
Task 1: Calculate cavern pressure evolution during <strong>the</strong> test<br />
Task 2: Calculate <strong>long</strong>-<strong>term</strong> cavern temperature evolution<br />
Task 3: Assess casing/casing shoe leaks during <strong>the</strong> test<br />
• DETERMINATION OF SALT PARAMETERS<br />
- Mechanical parameters<br />
• elasticity<br />
• secondary creep (Nor<strong>to</strong>n-H<strong>of</strong>f)<br />
- Hydraulical parameters: <strong>salt</strong> permeability at cavern scale<br />
• LONG-TERM FEM COMPUTATIONS PREDICTIONS<br />
5<br />
ANALYSIS OF A PRE-ABANDONMENT TEST<br />
Wellhead measurements Sonar survey Cavern temperature measurement<br />
Cavern pressure evolution Cavern mesh Cavern temperature evolution<br />
Cavern fluid(s) properties<br />
Rock <strong>salt</strong> properties<br />
LONG-TERM COMPUTATIONS<br />
6<br />
3
ANALYSIS OF A PRE-ABANDONMENT TEST<br />
Wellhead measurements Sonar survey Cavern temperature measurement<br />
Cavern pressure evolution Cavern mesh Cavern temperature evolution<br />
Cavern fluid(s) properties<br />
Rock <strong>salt</strong> properties<br />
LONG-TERM COMPUTATIONS<br />
7<br />
Task 1: De<strong>term</strong>ination <strong>of</strong> cavern pressure evolution during <strong>the</strong> test<br />
Pressures measured at well head<br />
Cavern pressure<br />
Well data<br />
• columns composition<br />
• temperature log<br />
• fluids compressibilities<br />
• possible leaks<br />
8<br />
4
His<strong>to</strong>ry <strong>of</strong> Wellhead Pressures<br />
9<br />
His<strong>to</strong>ry <strong>of</strong> Ground Temperature<br />
10<br />
5
His<strong>to</strong>ry <strong>of</strong> Atmospheric Pressure<br />
11<br />
A FILTERING TOOL IS EMBEDDED<br />
Wellhead pressure<br />
Ground temperature<br />
Atmospheric pressure<br />
12<br />
6
Measured pressure<br />
Corrected pressure<br />
13<br />
Earth tides<br />
Right-click on corrected pressure spectrum<br />
14<br />
7
Task 1: De<strong>term</strong>ination <strong>of</strong> cavern pressure evolution during <strong>the</strong> test<br />
Corrected pressures at well head<br />
Corrected cavern pressure<br />
Well data<br />
• columns composition<br />
• temperature log<br />
• fluids compressibilities<br />
• possible leaks<br />
15<br />
Well Data in LOCAS<br />
Strings database<br />
Fluids database<br />
Rocks database<br />
Layers database<br />
Sections database<br />
Stratigraphic cross-section view<br />
Well architecture view<br />
16<br />
8
LIQUIDS DATABASE<br />
17<br />
PURE GASE DATABASE<br />
18<br />
9
NATURAL GASES DATABASE<br />
19<br />
SECTIONS DATABASE<br />
20<br />
10
WELL ARCHITECTURE<br />
Section #2<br />
Section #3<br />
Section #5<br />
21<br />
INJECTIONS/WITHDRAWALS DATABASE<br />
Data can be loaded from a flow measurement file<br />
22<br />
11
COLUMNS DATABASE<br />
It’s possible <strong>to</strong> have up <strong>to</strong> 4 different fluids in each column (3 interfaces)<br />
23<br />
HISTORY OF CAVERN PRESSURE<br />
24<br />
12
ANALYSIS OF A PRE-ABANDONMENT TEST<br />
Wellhead measurements Sonar survey Cavern temperature measurement<br />
Cavern pressure evolution Cavern mesh Cavern temperature evolution<br />
Cavern fluid(s) properties<br />
Rock <strong>salt</strong> properties<br />
LONG-TERM COMPUTATIONS<br />
25<br />
CAVERN GEOMETRY IN LOCAS<br />
2D axisymetrical <strong>caverns</strong><br />
Simple shape (sphere, cylinder) or Real shape from sonar survey<br />
Av. cavern radius as a function <strong>of</strong> depth<br />
Embedded mesher<br />
Meshing parameters<br />
Cavern mesh<br />
Meshes databases<br />
26<br />
13
CAVERN PROFILE FROM SONAR SURVEY<br />
Load file from sonar survey<br />
27<br />
MESHING PARAMETERS<br />
28<br />
14
MESH VIEW<br />
29<br />
30<br />
15
3D VIEW<br />
31<br />
SPR2<br />
32<br />
16
MESHES DATABASE<br />
33<br />
ANALYSIS OF A PRE-ABANDONMENT TEST<br />
Wellhead measurements Sonar survey Cavern temperature measurement<br />
Cavern pressure evolution Cavern mesh Cavern temperature evolution<br />
Cavern fluid(s) properties<br />
Rock <strong>salt</strong> properties<br />
LONG-TERM COMPUTATIONS<br />
34<br />
17
Task 2: De<strong>term</strong>ination <strong>of</strong> <strong>long</strong>-<strong>term</strong> cavern temperature evolution<br />
- De<strong>term</strong>ination <strong>of</strong> natural rock temperature T <br />
- Fitting <strong>of</strong> a cavern temperature measurement<br />
Accurate <strong>predict</strong>ion <strong>of</strong><br />
brine temperature evolution<br />
brine <strong>the</strong>rmal expansion<br />
35<br />
SPR2 Geo<strong>the</strong>rmal Temperature<br />
SPR2 - Logs de température et calage gradients SPR3<br />
Temperature (°C)<br />
Température (°C)<br />
13 14 15 16 17 18 19 20 21<br />
0<br />
50<br />
100<br />
<strong>of</strong>ondeur / sol (m)<br />
Depth (m)<br />
Pro<br />
150<br />
200<br />
250<br />
300<br />
350<br />
Top <strong>of</strong> <strong>salt</strong><br />
T <br />
19.5 °C<br />
12/06/2002 moyenne<br />
20/08/2002 moyenne<br />
08/10/2002 moyenne<br />
1ères inclusions sel<br />
Sabot Casing<br />
Base Cheminée<br />
Landing Nipple<br />
SPR3 : 2,5 °C/100 m<br />
SPR3 : 1,2 °C/100 m<br />
400<br />
450<br />
36<br />
18
SPR2 TEMPERATURE MEASUREMENT IN 2002<br />
reference<br />
18.35°C – 058°C/year 0.58 37<br />
Cavern Temperature<br />
measurement<br />
T <br />
19.5 °C<br />
<br />
Accurate <strong>predict</strong>ion<br />
actual<br />
virtual<br />
Time<br />
July 2002<br />
38<br />
19
SPR2 CAVERN TEMPERATURE FITTING<br />
18.35 °C<br />
+0.58 °C/year<br />
Temperature<br />
1 st June 2000<br />
763 days<br />
1 st July 2002<br />
Time<br />
39<br />
ANALYSIS OF A PRE-ABANDONMENT TEST<br />
Wellhead measurements Sonar survey Cavern temperature measurement<br />
Cavern pressure evolution Cavern mesh Cavern temperature evolution<br />
Cavern fluid(s) properties<br />
Rock <strong>salt</strong> properties<br />
LONG-TERM COMPUTATIONS<br />
40<br />
20
BRINE PROPERTIES<br />
41<br />
SALT PROPERTIES<br />
• Mechanical properties<br />
• Elasticity<br />
• Creep: stationnary + transient<br />
4 implemented creep laws<br />
Nor<strong>to</strong>n-H<strong>of</strong>f<br />
Lemaitre-Menzel-Schreiner<br />
Munson-Dawson<br />
Lubby2<br />
+ possibility <strong>of</strong> reverse creep <strong>using</strong> a modified d Munson-Dawson law<br />
• Thermal properties<br />
• Hydraulical properties (micro-permeation)<br />
• Chemical properties (dissolution/crystallization)<br />
42<br />
21
Munson-Dawson Database<br />
43<br />
Salt Micro-permeation Properties<br />
44<br />
22
Calculation Steps<br />
45<br />
Phenomena that can be taken in<strong>to</strong> account:<br />
• Salt creep<br />
• Cavern fluid heating/cooling<br />
• Cavern fluid micro-permeation<br />
• Salt complementary dissolution/crystallization<br />
• Cavern fluid adiabatic compression/release<br />
Coupled through cavern compressibility<br />
Cavern pressure/temperature and casing leaks<br />
can be set or calculated<br />
46<br />
23
Example <strong>of</strong> parameters<br />
back-calculation<br />
47<br />
Salt parameters <strong>to</strong> be de<strong>term</strong>ined<br />
for <strong>long</strong>-<strong>term</strong> computations:<br />
‣ Salt elastic parameters <br />
E,<br />
<br />
<br />
‣ Salt creep parameters<br />
Stationnary creep: Nor<strong>to</strong>n-H<strong>of</strong>f parameters<br />
<br />
A, nQ , R<br />
<br />
‣ Salt hydraulical parameters<br />
<br />
hyd<br />
K <strong>salt</strong><br />
<br />
48<br />
24
Back-calculation <strong>of</strong> Salt Elastic Parameters<br />
Compressibility<br />
test<br />
V<br />
<br />
3<br />
3.97 m /MPa<br />
0.25<br />
assumed<br />
Finite Elements computation<br />
E 16,500 MPa<br />
49<br />
STATIONNARY PARAMETERS FITTED FOR TWO PERIODS<br />
Transient phase<br />
2 nd fitting period<br />
1 st fitting period<br />
50<br />
25
Selection <strong>of</strong> Parameters <strong>to</strong> be Fitted<br />
51<br />
Parameters <strong>to</strong> be Fitted<br />
Search domain<br />
52<br />
26
Selection <strong>of</strong> Fitted Periods<br />
53<br />
Selection <strong>of</strong> <strong>the</strong> Optimization Method<br />
54<br />
27
Fitting results can be emailed<br />
55<br />
Worst<br />
(hPa)<br />
lt permeability<br />
Sal<br />
Pressure<br />
computation<br />
measure<br />
Time<br />
Best<br />
Nor<strong>to</strong>n A parameter<br />
5×10 -20 m²<br />
4×10 -20 m²<br />
56<br />
28
INVESTIGATION OF FITTING SENSIBILITY<br />
57<br />
SPR2 - FITTING MAIN RESULTS<br />
hyd<br />
Salt permeability:<br />
K 3 4 <br />
10 m<br />
<strong>salt</strong><br />
20 2<br />
Salt stationnary creep:<br />
Q n<br />
<br />
<br />
Aexp<br />
<br />
RT <br />
(Nor<strong>to</strong>n-H<strong>of</strong>f law)<br />
-n<br />
A (/MPa -year)<br />
n<br />
Q R<br />
(K)<br />
2 possible sets<br />
<strong>of</strong> parameters<br />
Set #1 2.5 2.5 4100<br />
Set #2 7.8 5 4100<br />
58<br />
29
STATIONNARY PARAMETERS FITTED FOR TWO PERIODS<br />
Average pressure difference < 10 hPa<br />
59<br />
Long-<strong>term</strong> computation<br />
60<br />
30
Nor<strong>to</strong>n-H<strong>of</strong>f set #1<br />
hyd<br />
K <strong>salt</strong><br />
410 m<br />
20 2<br />
n 2.55<br />
2.5<br />
A 2.5 /MPa -year<br />
Q R 4100 K<br />
61<br />
SUBSIDENCE CALCULATION<br />
62<br />
31
NO-TENSION CRITERIA, DILATION CRITERIA…<br />
63<br />
EXAMPLE OF CONTOUR PLOTS<br />
It’s also possible <strong>to</strong> create movies (.avi)<br />
64<br />
32
CONCLUSIONS<br />
• Many features have been implemented in a <strong>s<strong>of</strong>tware</strong> called LOCAS<br />
• LOCAS can be helpful for various kinds <strong>of</strong> studies, as for instance:<br />
pressure/temperature <strong>predict</strong>ion including transient <strong>behavior</strong><br />
simulation <strong>of</strong> fast cycling loading – Natural gas, CAES<br />
<strong>long</strong>-<strong>term</strong> simulations (abandonment, subsidence)<br />
mechanical integrity tests (MITs) analysis<br />
short-<strong>term</strong> <strong>term</strong> stability (min./max. operating pressure)<br />
mechanical/<strong>the</strong>rmal/hydraulical parameters fitting from in situ tests<br />
Prediction from data at cavern scale<br />
65<br />
CONCLUSIONS<br />
‣ LOCAS supports all 32-bits Windows versions, Windows Seven included.<br />
‣ 3D & 64 bits versions under development.<br />
‣ LOCAS is not yet available for sale.<br />
Interested people, please contact Benoit Brouard:<br />
contact@Brouard-Consulting.com<br />
66<br />
33