bdpoc offspec risk assesment.pdf

1Vu Anh Tuan

From: Ba Mai Xuan [[email protected]]Sent: Thursday, April 25, 2013 7:12 PMTo: Tuan Vu AnhSubject: RE: Tnh ton kh HTMT offspecAttachments: ORA -offspec delivery.doc; Thanh phan khi HTMT (3.41 MB); BOD of HT.PDF

Kg A.Tun, lin quan n vn ny em bo co anh nh sau.

1. Ri ro v off spec kh HTMT:

- Tng hm lng N2+CO2 vt qu 6%: Khc vi chim so, trng hp ny kh xy ra v theo cc kt qu phn tch thnh phn tng thnh phn CO2 trong kh HTMT do BPOC cung cp ch l khong 2.98% (CO2 2.86%, N2 0.12%) thp hn rt nhiu so vi tiu chun qui nh. Trong trng hp xu nht cn c theo cc s liu trong BOD ca d n Bin ng 1 (trang 19-10 ti liu BOD nh km) hm lng CO2 cng ch ln n 3.89% - thp hn mc qui nh max 6%. => Nn ri ro v off spec kh HTMT v hm lng CO2_N2 kh xy ra c.

- WDP vt mc qui nh (max -10 OC 70 barg): Ri ro ny c th xy ra khi h thng tch nc bng glycol trn gin HT b upset s dn n nguy c: to hydrate dn n lm gim cng sut/shutdown NCSP tng t nh xy ra i vi kh 06.1 nm 2012, ngoi ra c th gy n mn ng ng, gy off-spec kh sales. Tuy nhin rt kinh nghim s c NCSP, hin c s d phng methanol inject vo h thng ca NCSP l gp i so vi nhu cu (60m3) v kh u ra gin HTMT c meter o dewpoint c a v NCSP gim st, ngoi ra NCSP cng c b o dewpoint/ly mu phn tch nh k nn v nguyen tt ri ro ny c th pht hin v kim sot c (bng cch dng nhn kh HTMT kh pht hin).

- Ri ro v hm lng H2S v total sulfur, hm lng Hg vt qui nh: cn c theo BOD d n bin ng 1 (trang 19 BOD nh km), kt qu phn tch thnh phn kh cc m HT v MT cho thy khng pht hin lng ng k no v hm lng H2S (y l c tnh cc m khu vc v NCSP, tng t kh 06.1 v 11.2). Cn v hm lng thy ngn th theo BOD kt qu phn tch 04 mu kh ch l 1 microgram/m3 thp hn nhiu so vi mc qui nh 82 microgram/m3 nh yu cu h thng NCSP. Nn ri ro ny cng kh xy ra tr kh c s sai lch ln gia cc mu phn tch vi s liu vn hnh thc t sau ny.

- HC DP v GCV cao hn mc qui nh: Ri ro ny xy ra khi h thng Dewpoint pointing b upset. Tuy nhin trn thc t h thng phn tch online kh u ra HTMT s cho php NCSP theo di v kim sot vic nay. Ngoi ra cc ch tiu ny s c NCSP kim sot thng qua h thng LTS ca NCSP ri. Cn i vi trng hp GCV nh hn 37 MJ/m3 th kh xy ra do bn cht ca kh HTMT.

- Ri ro v off spec thng s nhit v p sut: V T khng c ri ro do bn cht nhit nc bin. i vi p sut c cc tn hiu bo v PSHH, p sut thp th kh HTMT s khng vn chuyn vo ng ng c.

Trn c s cc phn tch trn, theo em th ri ro ln nht l WDP b off-spec tuy nhin mnh c gii php pht hin v ngn nga nn hu qu khng ng k. Hin nay trong cng thc trc y Ban KTSX v NCSP phi hp xy dng ch tnh ton c cho trng hp CO2 cao trong kh chim so. i vi WHP nh bo co trc y do c cc gii php phng nga nn khng cn phi tnh ton (vi li cng cha bit Phng n tnh nh th no na ). Cc bn lin quan cng lp nh gi ri ro v kh HTMT a vo b off spec v cc bin php phng nga lm c s chun b ti liu m phn. Em gi anh nh nh km tham kho thm. Em bo co anh nh trn xem xt, nu cn thm thng tin hoc anh c ch o tnh ton g thm em thc hin .

2Trn trng, MXBa. From: Tuan Vu Anh [mailto:[email protected]] Sent: Thursday, April 25, 2013 1:34 PM To: Ba Mai Xuan Subject: Tnh ton kh HTMT offspec Ba, Sng anh trao i vi anh Huy c tnh hnh nh sau, hin nay trong TA cn vng 1 lo ngi l khi HTMT b offspec th cc ch kh khc (TNK, KNOC) b offspec theo. V vy bi ton t ra tng t nh lm vi Chim So, l khi HTMT offspec th:

- mc lu lng bnh thng, ngun kh trn c b offspec ko? - Nu c kh nng kh trn b offspec th tng ng vi cp kh HTMT offspec trong bao lu (volume ca

HTMT offspec) -> gii php ngn nga offspec kh trn Em m li file ca Thin NCS tnh trc y, update cc thng tin tnh th xem nh th no nh Best regards, Vu Anh Tuan - General Manager Technical & Production Division PETROVIETNAM GAS CORPORATION

WCC LEVEL 2 RISK ASSESSMENT - VIETNAM Operational Risk Assessment

Number: ORA -

TASK Abnormal Operating Condition Shippers deliver off-spec fluids

Normal Function Shippers deliver on-spec fluids and the NCSP transportation system works as designed redelivering treated gas/condensate meting redelivery specifications as stated in TA

Tag No. (as applicable) N/A

HAZARD ANALYSIS Refer to "Risk Assessment Tables" in Part 4 of document OPS-3000-MP-1014 'Work Control System'

Hazard

Hazard Effect Rating

Existing and Proposed Control Measures Residual Risk Rating

Hazard Effect

Probability Risk Hazard Effect

Probability Risk

Delivery gas having WDP higher than spec (>-100C@70barg)

- Hydrate formation at NCSP which require MeOH consumption ($50K) and could lead to NCSP capacity reduction (max at 15Msm3/day for 2days)

B L L

- AAMM requires each offshore facility equipped with 2 online WDP analyzers.

- NCSP Terminal is equipped with 1 online WDP analyzer - All online WDP analyzers performance is ensured by planned maintenance

program (PMR) and cross-checked by laboratory WDP analyzer regular (weekly & monthly).

- Online WDP analyzers readings are lively transferred to NCSP CR and NCSP CRTs track them continuously for early prediction/alarm

- The Production Coordination Procedures-OPS-3000-MP-2133 between NCSP and all Shippers in place (Offshore CRTs to inform to NCSP CRTs of the Glycol system performance & WDP readings by telephone followed by fax with estimated volume/duration)

- NCSP processing system (Terminal) is equipped with appropriate PDTs to predict hydrate formation and proactively dehydrate

- Dehydrate system (MeOH injection system) is available all time (2 x 100% availability)

- Relevant operating procedures (Gas Dew-pointing, MeOH Injection) in place and competency of process operators (CRT & Production Technicians) is assured by competency assurance system (PCAN)

- MeOH inventory is assured at an appropriate level (60m3)

B L L

- Damage to the NCSP 26 pipeline and processing system (Terminal) due to corrosion A VL L






- Corrosive substances (H2S, CO2) present in NCSP pipeline system at low level (due to TA spec requirements and nature of NCS offshore reservoirs)

- NCSP pipeline system is designed at high conservation level conforming to ASME B31.8

- Corrosion probes/coupons at offshore facilities outlet & NCSP Terminal inlet are installed and routinely checked

- Corrosion inhibitor injected continuously at NCSP pipeline inlet (LTP) - Sphering/pigging equipment and program are in place

A VL L

- NCSP processing system (Terminal) can not handle the off-spec delivery fluids causing off-spec redelivery gas on WDP parameter. This makes corrosion to 30 pipeline, quality excursion blame from Shippers

A VL L






- NCSP processing system (Terminal) is equipped with appropriate PDTs to predict hydrate formation and proactively dehydrate

- Dehydrate system (MeOH injection system) is available all time (2 x 100% availability)

- There is a conservation in quality assurance in commercial arrangement (TA) as WDP is required < -100C@70barg for delivery gas but

Delivery gas having inert gases content higher than spec (%N2 + %CO2 > 6.0%mol)

- Damage to the NCSP pipeline and processing system (Terminal) due to corrosion A VL L

- AAMM requires each offshore facility equipped with 2 online Gas Chorography analyzers for CO2 & N2 contents.

- NCSP Terminal is equipped with 2 online Gas Chorography analyzers - All Gas Chorography analyzers performance is ensured by planned

maintenance program (PMR) and cross-checked by laboratory Gas Chorography analyzer regular (weekly & monthly).

- Online Gas Chorography analyzers readings are lively transferred to NCSP CR and NCSP CRTs track them continuously for early prediction/alarm

- Water content in NCSP pipeline system is controlled at very low level (

- Serious health impact (cancer) to workers A VL L

- CS FPSO is equipped with MRU and its working performance is closely monitored and reported to NCSP daily

- TA/AGGA with Blk12.W require periodical analysis to cross check - NCSP is applying "Environmental Monitoring Program" to check Hg content

in waste water periodically - NCSP is applying "Mercury Monitoring Program" to check Hg content in

inlet/outlet fluids periodically - NCSP is applying WCS in which people working with HC must wear PPE

including mask

A VL L

- NCSP redelivers off-spec gas on particles content leading to quality excursion blame from Shippers

B VL VL

- CS FPSO is equipped with MRU and its working performance is closely monitored and reported to NCSP daily

- TA/AGGA with Blk12.W require periodical analysis to cross check - NCSP is applying "Environmental Monitoring Program" to check Hg content

in waste water periodically - NCSP is applying "Mercury Monitoring Program" to check Hg content in

inlet/outlet fluids periodically - NCSP pipeline system is very long which absorbs almost the Hg in inlet

fluids - There are filters at Terminal inlet and outlet (Phu My GDC)

A VL VL

Delivery gas having sulfur content (H2S>20ppm and/or total S > 30ppm)

- Damage to the NCSP pipeline and processing system (Terminal) due to corrosion A VL L

- Sulfur contents in NCS offshore reservoirs are stable at very low level (max 10ppm)

- TAs require H2S & Total sulfur analysis periodically (monthly) for inlet/outlet gas

- Water content in NCSP pipeline system is controlled at very low level (

- NCSP liquid processing system (Condensate trains) can not handle the off-spec delivery fluids causing flooding of slug-catcher and production stoppage

A VL L

- AAMM requires each offshore facility equipped with 2 online Gas Chorography analyzers for HCDP & GCV.

- NCSP Terminal is equipped with 2 online Gas Chorography analyzers - All Gas Chorography analyzers performance is ensured by planned

maintenance program (PMR) and cross-checked by laboratory Gas Chorography analyzer regular (weekly & monthly).

- Online Gas Chorography analyzers readings are lively transferred to NCSP CR and NCSP CRTs track them continuously for early prediction/alarm

- The limit of HCDP and high GCV is set up with a high conservation in referring to phase envelop of delivery gas

- Capacity of condensate processing system is high compared with liquid drop-out from inlet fluids

- Untreated condensate can be temporarily stored in slugcatcher (2,400m3) & condensate storage tanks (15,600m3)

A VL L

Delivery gas having Temperature & pressure out of specs * This risk is zero due to nature of pipeline operational requirements (pressure) and stable temperature at seabed

- N/A N/A N/A N/A - N/A N/A N/A N/A

ACTIONS

Hazard Action Equipment, PPE, Manpower Required Person Responsible Date By

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-

-

-

OPERATIONAL HAZARDS The lists of hazards below are provided for guidance - they should not be regarded as complete RA TEAM For work permits etc the form should be reviewed and signed by the area authority, and approved and signed by the OIM or site controller. For other activities the reviewer and approver should be the two most senior persons on the site, installation or vessel.

potential for loss of containment temperature control system (DCS) safety system Date Name Title Signature vibration pressure ESD damage to equipment Participants level potential for ignition vendor trip/ alarm

Prepared by Reviewed by

Approved by

Memo StyleORA -offspec delivery _2_.docBOD of HT.PDF

bdpoc offspec risk assesment.pdf

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