09.00 CO2
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Transcript of 09.00 CO2
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Managing integrity of large volumes of wells volumes of wells
By Paul Hopmans By: Paul Hopmans Well integrity principal technical expert expert Shell Projects & Technology
Copyright of Royal Dutch Shell plc
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Managing well integrity of large number of wells
We currently manage the integrity of some 15,000 wells using Shell developed system ,called eWims.
We manage the wells in accordance to the latest standards that are available with in latest standards that are available with in Shell and industry.
Validation of as build is an ongoing project Validation of as build is an ongoing project that will confirm well operating envelops.
Management of internal & external corrosion with changing operating conditions is a challenge.
What will change with CO2 sequestration?
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eWims Well Integrity Management System
eWims is a system that handles 15,000 wells Allows you to manage / overview the status of your wells on.
Preventive maintenance tasks Corrective maintenance tasks Annular pressure monitoring Blow down and top up Conductor inhibitor Conductor inhibitor treatment External corrosion monitoring Casing load calculation Well head growth / Well head growth / subsidence Trigger pressures alarms Production data upload Maasp & mechanical Maasp & mechanical data EDM Compliance KPIs Notifications to SAP / FSR Deviations
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Well Integrity in design requires that
Operating conditions are defined
Physical behavior is
Operating envelop
Xmas tree and well head pressure rating Physical behavior is
modeled and analyzed Functional failure modes
are considered
pressure rating and ESD test criteria.
Know your
Safety critical elements are identified
Performance standards of
Annulus Maximum allowable surface pressure (MAASP )
safety critical elements are quantified
SCSSSV test frequency and leak criteria
Know your What are the changes of CO2
sequestration in our design envelop to manage well integrity ?
Know your strength of reservoir ( leak off )
Strength of casing integrity ? simulate strength ( Stress Check)
Strength of tubing simulate stress behavior ( Well
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ABC
Risk of CO2 with annular communication
ABC Risk of out flow due to
packer failure or tubing failure that 30
20 Fluidleak-off to
tubing failure that may cause casing internal corrosion and breach around shoe 20 Fluid leakoff to C Annulus
Formation Seepage through
annulus from 13 3/8 Fluid leak-off to
B Annulus Formation
reservoir micro annuli that may corrode casing externally and cause out flow
9 5/8
P d ti
cause out flow
Well collapse due to casing corrosion Production
Tubingcasing corrosion
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Risk associated with casing failure jump or slump
Reducing the wall loss through external corrosion can lead to a loss of containment but also to structural failure
Loads are highest in injection wells and when the well cools
Flow line
Loading on S. CsgLoading on S. CsgLoading on S. CsgTbg : + 132PC : + 275IC : + 85
Tbg : + 132PC : + 275IC : + 85 Loading on S. Csg
Tbg : + 14PC : + 95IC : -209 !!
As built datum
-511 kipsOn SCsg +190 kips
Surface Casing is now in tension
Top of Conductor
Mud lineOn flowing the casings heats up reducing tensile forces. In this case the load in the IC is
07 May 2010 6
static Prod
the load in the IC is now UP
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CO2 sequestration challenges to Well Integrity
Risk of failure due to loss of external casing barriers (CO2 leak and poor cement bonds)
Industry field reviews for CO2 sequestration have demonstrated that we may have not constructed our wells or abandoned them in view of for CO2 sequestration.
Risk assessment in changes to well operating envelop for CO2 sequestration is being debated no clear for CO2 sequestration is being debated, no clear standard (DNV is working a proposal in a JIP)
Iso standard proposal via OGP in preparation supported by the major operators to address wells lifecycle by the major operators to address wells lifecycle integrity in operate phase
Well integrity management standards & systems are not inclusive of CO2 sequestration risks.
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Check list when you change a well to CO2 injectorCO2 injector
Casing and tubing and tubing accessories and wellhead (such as packer, flow control nipples, SCSSV, etc) all ( , , , )meet CO2 materials spec?
Casing and tubing system meet injection pressure requirements - Well cat has been modeled? requirements Well cat has been modeled?
Confidence in cap rock and cement seal for the reservoir pressures expected during injection?
Testing can be done to confirm this in the near well bore region (tracer injection tests, temp logs, etc.)
Cement integrity confirmed and type of cement used on production casing.
CO2 ratios are important to know for both cement integrity and material corrosion integrity and material corrosion.
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Check list when you change a well to CO2 injector
Casing design i.e. material compatibility, from field perspective - like we have seen with upper and lower intervals separately explored
Wellheads, and xmass tree, seals and feed through - check compatibility for CO2, may have to flush valves with specific grease. Check with wellhead manufacturer
Pressure gauges transducers and other threaded Pressure gauges , transducers and other threaded & fitted components to well need to be checked for CO2 compatibility
Wellhead control panel needs to be checked for Wellhead control panel needs to be checked for CO2 compatibility as flow back from control line can enter and hit panel.
Annular monitoring in event of annular communication problems - are there current existing sustained annulus pressures and have