Field Joint Coatings for Deep Sea Pipelines
1
Field Joint Coatings for Deep Sea Pipelines Field Joint Coatings for Deep Sea Pipelines Robrecht Verhelle 1 , Luk Van Lokeren 1 , Samir Loulidi 1 , Helen Boyd 2 , Guy Van Assche 1 Robrecht Verhelle 1 , Luk Van Lokeren 1 , Samir Loulidi 1 , Helen Boyd 2 , Guy Van Assche 1 1. Vrije Universiteit Brussel, Physical Chemistry & Polymer Science, Pleinlaan 2, 1050 Brussels, Belgium; 2. Heerema Marine Contractors, Vondellaan 55, 2300 PH Leiden, The Netherlands. Heerema Marine Contractors Heerema Marine Contractors Heerema Marine Contractors (HMC) is contracted to install Although the individual pipe sections (12 m) are coated with a Heerema Marine Contractors (HMC) is contracted to install pipelines in the sea. The metallic pipes, generally of carbon steel, need not only to be protected against corrosion, but also to be insulated to maintain the temperature of the pipe Although the individual pipe sections (12 m) are coated with a factory-applied coating along their full length, the coating is cut back at the ends before welding them together during a J-lay or reel-lay installation. After welding, a field joint coating is applied over the to be insulated to maintain the temperature of the pipe contents and assure the flow. Therefore a multilayer polymer coating is applied. installation. After welding, a field joint coating is applied over the welded area. Ensuring optimal application conditions for the coating during an offshore installation is far from straightforward. Pipe sections Surface cleaning FBE application Injection moulding Field joint Pipe sections Welded together Surface cleaning Grit blasting FBE application Corrosive protection Injection moulding Thermal insulation Field joint Needs cooling Objectives Cross section model with dimensions (mm) and boundary conditions: symmetric, outflow, convective cooling h , convective cooling h In order to optimise the application process of the field joint coating, deep insight into the cure symmetric, outflow, convective cooling h 1 , convective cooling h 2 In the first part of this research project, the cooling process of a field joint and crystallisation kinetics, together with a good comprehension of the heat transfer in the field joint is required. Experimental data on the raw coating is simulated, computing the temperature and crystallinity profiles, throughout the coating, as a function joint is required. Experimental data on the raw materials, acquired by thermal analysis, will be used to determine the crystallisation 1 and cure 2 kinetics model, which will consequently be throughout the coating, as a function of time using the cure and crystallisation kinetics model obtained from experimental data. L 1200.00 TS 15.70 Lcutback 313.00 TIMPP 52.59 kinetics model, which will consequently be implemented in the computational finite element model. from experimental data. Lcutback 313.00 TIMPP 52.59 Lchamfer 91.10 T3LPP 9.19 Loverlap 50.00 T4L 39.40 1. J.D. Hoffman, R.L. Miller, Polymer 1997, 38, 3151-3212 2. G. Van Assche, A. Van Hemelrijck, H. Rahier, B. Loverlap 50.00 T4L 39.40 T5L 4.00 2. G. Van Assche, A. Van Hemelrijck, H. Rahier, B. Van Mele, Thermochim. Acta 1995, 268, 121-142 Computational Methods Dependent variable u Source term f Computational Methods All computations are performed in COMSOL ODE parameters for the crystallisation kinetics model In order to obtain stable and low time- consuming computations, preferably the PARDISO solver was used, together with Dependent variable u Source term f N Multiphysics. The crystallisation kinetics model was incorporated as a set of ODEs, 3 all of form ( ) dt dT dT T dN dt d T q N ) ( 1 1 1 ) ( 0 α α α - + - + - PARDISO solver was used, together with the BDF timestepping method. N at Where u is the dependent variable, d the f t u d t u e a a = ∂ ∂ + ∂ ∂ 2 2 dt dT dt 1 α - α - 1 ) ( N T q Furthermore, to avoid mathematically correct but physically unrealistic data for the relative crystallinity α (i.e. α ∈ [0,1]), α F Where u is the dependent variable, d a the damping coefficient, e a the mass coefficient and f the source term. Since our model only has first α - 1 ( ) ( ) Q FP N F G at + - - 2 1 4 2 α π ) ( T G the relative crystallinity α (i.e. α ∈ [0,1]), and the amount of nuclei N (i.e. N > 0), both parameters were limited using transformation functions: F P f the source term. Since our model only has first order time derivatives, all mass coefficients e a are always zero. Furthermore, all equations are written so that the damping coefficient d equals α - 1 ) ( T FNq transformation functions: 2 1 2 ) ( + = b erf α N e N log = Q written so that the damping coefficient d a equals 1. α - 1 ) ( 2 T Nq F 2 2 3. J.M. Haudin, J.M. Chenot, Intern. Polym. Process 2004, 19, 267-274 & 275-286 Results A1-2-3-4-5: Centre of the FJC Temperature and relative crystallinity profiles were computed for different geometries (e.g. with and without a mould, representing an with and without a mould, representing an immediate removal/opening of the mould after the injection and a complete cooling in the mould), different pretreatments (preheating of B1-2-3-4-5: Centre of the cutback mould), different pretreatments (preheating of steel pipe and factory applied coating) and different start and boundary conditions (e.g. Temperature (left) and relative crystallinity (right) profile temperature of melt, mould and air). Points of interest were selected in the model C1-2-3-4-5: Cutback Temperature (left) and relative crystallinity (right) profile of the FJC after 120 min. Perspectives Points of interest were selected in the model with the perspective to be compared with industrial test results. This validation step, a confrontation of the computational results with Perspectives In the last quarter of 2014, the computed temperature and crystallinity profiles will be confrontation of the computational results with the experimental results on the industrial scale, is planned in the last quarter of 2014. D1-2-3-4-5: Parallel to the chamfer temperature and crystallinity profiles will be compared to industrial test results. Shrinkage during cooling and crystallisation will be D1-2-3-4-5: Parallel to the chamfer Shrinkage during cooling and crystallisation will be implemented in the model, using experimental (lab-scale) results in order to predict and to Locations of computed temperatures and crystallinities in the field joint coating. Relative crystallinity Temperature (lab-scale) results in order to predict and to evaluate internal and interfacial stresses. Filling of the mould will eventually be implemented. This research was carried out under project number M31 in the field joint coating. Relative crystallinity Temperature Filling of the mould will eventually be implemented. This research was carried out under project number M31 6 12469 in the framework of the Research Program of the Materials innovation institute M2i (www.m2i.nl). Excerpt from the Proceedings of the 2014 COMSOL Conference in Cambridge
Transcript of Field Joint Coatings for Deep Sea Pipelines
Field Joint Coatings for Deep Sea PipelinesField Joint Coatings for Deep Sea PipelinesRobrecht Verhelle1, Luk Van Lokeren1, Samir Loulidi1, Helen Boyd2, Guy Van Assche1Robrecht Verhelle1, Luk Van Lokeren1, Samir Loulidi1, Helen Boyd2, Guy Van Assche1
1. Vrije Universiteit Brussel, Physical Chemistry & Polymer Science, Pleinlaan 2, 1050 Brussels, Belgium; 1. Vrije Universiteit Brussel, Physical Chemistry & Polymer Science, Pleinlaan 2, 1050 Brussels, Belgium;
2. Heerema Marine Contractors, Vondellaan 55, 2300 PH Leiden, The Netherlands.
Heerema Marine ContractorsHeerema Marine ContractorsHeerema Marine Contractors (HMC) is contracted to install Although the individual pipe sections (12 m) are coated with aHeerema Marine Contractors (HMC) is contracted to installpipelines in the sea. The metallic pipes, generally of carbonsteel, need not only to be protected against corrosion, but alsoto be insulated to maintain the temperature of the pipe
Although the individual pipe sections (12 m) are coated with afactory-applied coating along their full length, the coating is cut backat the ends before welding them together during a J-lay or reel-layinstallation. After welding, a field joint coating is applied over theto be insulated to maintain the temperature of the pipe
contents and assure the flow. Therefore a multilayer polymercoating is applied.
installation. After welding, a field joint coating is applied over thewelded area. Ensuring optimal application conditions for the coatingduring an offshore installation is far from straightforward.coating is applied. during an offshore installation is far from straightforward.
Pipe sections Surface cleaning FBE application Injection moulding Field jointPipe sections
Welded together
Surface cleaning
Grit blasting
FBE application
Corrosive protection
Injection moulding
Thermal insulation
Field joint
Needs cooling
Objectives Cross section model with dimensions (mm) and boundary conditions:
symmetric, outflow, convective cooling h , convective cooling hObjectivesIn order to optimise the application process ofthe field joint coating, deep insight into the cure
symmetric, outflow, convective cooling h1, convective cooling h
2
In the first part of this research project,the cooling process of a field joint
and crystallisation kinetics, together with a goodcomprehension of the heat transfer in the fieldjoint is required. Experimental data on the raw
the cooling process of a field jointcoating is simulated, computing thetemperature and crystallinity profiles,throughout the coating, as a functionjoint is required. Experimental data on the raw
materials, acquired by thermal analysis, will beused to determine the crystallisation1 and cure2
kinetics model, which will consequently be
throughout the coating, as a functionof time using the cure andcrystallisation kinetics model obtainedfrom experimental data.
L 1200.00 TS 15.70
Lcutback 313.00 TIMPP 52.59kinetics model, which will consequently beimplemented in the computational finite elementmodel.
from experimental data.Lcutback 313.00 TIMPP 52.59
Lchamfer 91.10 T3LPP 9.19
Loverlap 50.00 T4L 39.40
1. J.D. Hoffman, R.L. Miller, Polymer 1997, 38,
3151-3212
2. G. Van Assche, A. Van Hemelrijck, H. Rahier, B.model. Loverlap 50.00 T4L 39.40
T5L 4.00
2. G. Van Assche, A. Van Hemelrijck, H. Rahier, B.
Van Mele, Thermochim. Acta 1995, 268, 121-142
Computational Methods
Dependent variable u Source term f
Computational MethodsAll computations are performed in COMSOL
ODE parameters for the crystallisation kinetics modelIn order to obtain stable and low time-consuming computations, preferably thePARDISO solver was used, together withDependent variable u Source term f
N
All computations are performed in COMSOLMultiphysics. The crystallisation kinetics modelwas incorporated as a set of ODEs,3 all of form ( )
dt
dT
dT
TdN
dt
dTqN
)(1
1
1)( 0α
α
α−+
−+−
PARDISO solver was used, together withthe BDF timestepping method.
Nat
Where u is the dependent variable, d the
ft
ud
t
ue aa =
∂
∂+
∂
∂2
2 dtdTdt1 α
−
α−1
)( NTqFurthermore, to avoid mathematicallycorrect but physically unrealistic data for
the relative crystallinity α (i.e. α ∈ [0,1]),α
F
Where u is the dependent variable, da thedamping coefficient, ea the mass coefficient andf the source term. Since our model only has first
α−1
( ) ( )QFPNFG at +−− 214 2απ
)(TG
the relative crystallinity α (i.e. α ∈ [0,1]),and the amount of nuclei N (i.e. N > 0),both parameters were limited usingtransformation functions:F
P
f the source term. Since our model only has firstorder time derivatives, all mass coefficients ea
are always zero. Furthermore, all equations arewritten so that the damping coefficient d equals
)(TG
α−1
)(TFNqtransformation functions:
2
1
2
)(+=
berfα NeN log=
Q
written so that the damping coefficient da equals1.
α−1
)(2 TNqF22
+=α eN =
3. J.M. Haudin, J.M. Chenot, Intern. Polym. Process
2004, 19, 267-274 & 275-286
ResultsA1-2-3-4-5: Centre of the FJC
Temperature and relative crystallinity profileswere computed for different geometries (e.g.with and without a mould, representing anwith and without a mould, representing animmediate removal/opening of the mould afterthe injection and a complete cooling in themould), different pretreatments (preheating of
B1-2-3-4-5: Centre of the cutback
mould), different pretreatments (preheating ofsteel pipe and factory applied coating) anddifferent start and boundary conditions (e.g.
Temperature (left) and relative crystallinity (right) profile different start and boundary conditions (e.g.temperature of melt, mould and air).
Points of interest were selected in the modelC1-2-3-4-5: Cutback
Temperature (left) and relative crystallinity (right) profile
of the FJC after 120 min.
PerspectivesPoints of interest were selected in the modelwith the perspective to be compared withindustrial test results. This validation step, aconfrontation of the computational results with
Perspectives
In the last quarter of 2014, the computedtemperature and crystallinity profiles will beconfrontation of the computational results with
the experimental results on the industrial scale,is planned in the last quarter of 2014. D1-2-3-4-5: Parallel to the chamfer
temperature and crystallinity profiles will becompared to industrial test results.
Shrinkage during cooling and crystallisation will beis planned in the last quarter of 2014. D1-2-3-4-5: Parallel to the chamfer
Shrinkage during cooling and crystallisation will beimplemented in the model, using experimental(lab-scale) results in order to predict and to
Locations of computed temperatures and crystallinities
in the field joint coating. Relative crystallinity Temperature
(lab-scale) results in order to predict and toevaluate internal and interfacial stresses.
Filling of the mould will eventually be implemented.
This research was carried out under project number M31
in the field joint coating. Relative crystallinity Temperature Filling of the mould will eventually be implemented.
This research was carried out under project number M31
6 12469 in the framework of the Research Program of
the Materials innovation institute M2i (www.m2i.nl).
Excerpt from the Proceedings of the 2014 COMSOL Conference in Cambridge
