De-bottlenecking of gathering stations of UGS Dolní Dunajovice

De-bottlenecking of gathering stations of UGS Dolní Dunajovice

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innogy Gas Storage is the largest Czech Underground Gas Storage (UGS) operator

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Overview of innogy Gas Storage

2007Companyfounded 6

Facilitiesoperated

2.7bcm

stored 12EUR mil.CAPEX*33

EUR mil.EBIT*

73EUR mil.

Revenues*

214FTE

employed

RWE AG

innogy

Grid Retail Renewables

innogy Česká republika

GasStorage

GasGrid

Retail

Power Generation, CNG

innogy Gas Storage

Location within RWE Basic Facts&Figures

* Figures of 2015

innogy GS operates six UGS facilities in concept of one virtual storage

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Overview of innogy Gas Storage

Consumption

Transmission

Working gas volume:

Injectioncapacity:

Withdrawalcapacity:

Capacity of innogy GS virtual UGS

28.7 TWh (2.7 bcm)

316 GWh/day

422 GWh/day

Market share by volume operated

68 %

32 %

innogy Gas Storage Other operators

UGS Dolni Dunajovice basic facts

• UGS Dolní Dunajovice is located close to town of Mikulov in the South Moravia and it is the biggest underground gas storage in Czech Republic

• UGS object was developed in partly depleted gas field Dolní Dunajovice which was discovered in 1973 by exploration well DUN-1

• Reservoir was formed in Lower Miocene (Eggenburgian sandstones) in the upper block of Vestonice fault in the average depth of 1050 m below surface

• Eggenburgian sandstones thickness ranges from 15 m up to thickness of 70 m . Average Eggenburgian sandstones porosity is 22 % and permeability ranges from tens of mD up to the hundreds of mD

• Reservoir is sealed by overlying Eggenburgian claystones and by Vestonice fault

• UGS facility construction started in 1985 and in 1989 it became operational

• Working gas volume is 900 mcm, actual max withdrawal rate is 19 mcm/day, injection capacity is about 12 mcm/day

• There has been drilled 64 wells, 47 of which are operated as injection/withdrawal wells up to date.

• UGS has 4 gathering stations, 4 compressors used for injection and it is connected into TSO 2 x DN500 PN63 pipeline


UGS Dolni Dunajovice development potential

• UGS D. Dunajovice was selected as priority candidate for evaluation of itsdevelopment potential due to its working gas volume, underground part performance and favourable pipeline connection

• Pre-design study was ordered from ATEKO company in 2010 to identify possiblescenarios for withdrawal rate increasing

• Internal study was elaborated in 2011 in order to evaluate of all subsurface and surface development possibilities and proof their geological/technical feasibilities

• Immediate outputs from above mentioned two studies was identification ofsignificant potential in subsurface part (esp. withdrawal rate) and confirmation ofbottlenecks in surface technology of gathering stations and TSO fiscal meteringstation.

• Identification of bottlenecks was done in SW Hysys using these inputs:• Well performance based on well testing

• Well connection pipeline data (lenght, diameter, roughness, vertical profile, temperature transfer

• Gas composition and water content (free water, water vapour)

• Decription of gas processing technology at gathering stations (line separators dimensions and itseffectivness), orifice flow meters parameters (accuracy vs. flow rates), regulating valves(dimensions and acting), joint separators (dimensions and its effectivness), dehydration absorbtioncolumns (dimensions and its effectivness, operation experience)

• Measured data from UGS control sytem (pressure, flow rates, temperature, water dew point)


Process flow simulation in SW Hysys/Unisim


SS1

SS2

SS3

SS4

Scope of GS 1 reconstruction






UGS Dolni Dunajovice reconstruction projectdevelopment• Thanks to interest of our clients to offer them „faster products“ (higher withdrawal

rate) the economical evaluation of was performed with beneficial results and wassmoothly approved in RWE

• The project have to deliver following benefits :• Increasing of withdrawal rate up to 24 mcm/day and enables additional company income

• Provide independency of GS No. 1 and 2 on fiscal metering station at UGS plant with its limitationsand shorten UGS downtime, if necessary

• New set of projects was established and it consists of:• Reconstruction of gathering stations No. 1 (water separation and dehydration part)

• Reconstruction of gathering stations No. 2 (water separation and dehydration part)

• Reconstruction of gathering stations No. 1 (metering lines part)

• Reconstruction of gathering stations No. 2 (metering lines part)

• Reconstruction of gathering station No. 3 (all together)

• Construction of new fiscal metering and transfer station and TSO connection pipeline near GS No. 2

• Project designs for zoning permit, building approval and detail design were orderedand step by step elaborated.

• Beside of all necessary permits the important condition for project realization wasconcluding of connection agreement with TSO (Net4Gas, s.r.o.)


UGS D. Dunajovice reconstruction projects


Reconstructed gathering stations


New dehydrationcolumn (Ateko)New metering

line hall

New fire safe/fail savewell connection pipeline

armatures

Reconstructed gathering stations - AC


New dehydrationcolumn with

oriented packing

New continuousTEG discharge

Reconstructed gathering stations - AC


Oriented packingSultzer MelapakPlusfor new dehydration

column

Reconstructed gathering stations – metering hall


New coriolis massflow meter

(Micromotion)

Reconstructed gathering stations – metering hall


New line separator

New transfer station + connection pipeline




4 x fiscalmetering lines



DN700 PN63connection pipeline



Design vs. Test of absorbtion columns


Contracted values

Tested values

Lessons learnt

• Construction and technological parts of the project design have to be assessed together. (Dehydration column purchased in advance did not fit with roofing of thebuilding :o()

• Time consuming zoning permit obtaining (Ministry of Regional Development)

• Measurement of WDPT at the dehydration column inlet and outlet should be carriedout by two measurement principles. It is better to have redundancy in case of failureof one measuring method (Aurora+Anys)

• Time consuming negotiation with TSO regarding Connection agreement, delayedsignificantly GS3 reconstruction and construction of new transfer station.

• Better coordination of construction works and UGS downtimes with routine UGS operation as well as UGS well workovers.

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Conclusions

• Both GS1 and GS2 were successfully reconstructed in 2014 with partial WR increase.

• The testing proved that dehydration columns have met required parameters

• HAZOP provisions were included into the project with a CAPEX increasing impact

• A week ago GS3 reconstruction was also finished, further testing will take place during this withdrawal season

• Due to limitation of 19 mcm/day at existing TSO transfer station we have to wait til Feb 2017 when second transfer station is going to be finished

• For next season we expect full increase of WR as was planned

• Projects for reconstruction of water separation and dehydration technology were in schedule and within approved budget. Metering hall were more expensive and slightly delayed due to additional works related to emergency depressurizationproject interface and HAZOP study recommendation

• Several unresolved issues at GS are still under evaluation, esp.:

• heating power of boilers for gas preheating after increasing of WR,

• callibration of solid particles detection on UGS well heads during high rates,

• origin of these solid particles (residuals from well liquids/reservoir material), etc.

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Thank you for your attention!

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Documents

De-bottlenecking of gathering stations of UGS Dolní Dunajovice