Chong an Mon Oil and Gas

PETROVIETNAM

65DU KH - S 3/2014

1. M u

Theo nghin cu, n mn l mt trong nhng nguyn nhn hng u dn n h hng thit b v tht thot sn phm, chim n 25% tng h hng i vi ti sn, thit b. Nm 2012, M chi 6,2% GDP kim sot, ngn nga, khc phc hin tng n mn [2]. Trong cc nh my ch bin du kh, hin tng n mn c th xy ra do tip xc vi CO2 hay H2S; n mn ti cc v tr ng, n mn tip xc, n mn mi hn, n mn khe, rnh ng ng, n mn mt bch bn trong, n mn kh quyn bn ngoi, n mn di lp bc bo n, n mn nt gy do ng sut, n mn cc b thp khng g, n mn mi mn v n mn trong mi trng c cha thy ngn [3]. Vic kim sot, theo di v bo v chng n mn c vai tr rt quan trng trong vic m bo tnh ton vn ca cng trnh.

Cc k thut theo di n mn gm theo di in-line, online v offl ine [5]. Vic la chn phng php theo di n mn ph thuc vo nhiu yu t: thnh phn v tnh cht ca m cht, nhit , p sut, c tnh k thut ca thit b Thit b theo di in-line c lp trc tip vo v tr cn theo di, sau c tho ra phn tch nh k. K thut theo di online s dng cc thit b theo di c gn c nh hoc c th tho ri vo v tr cn theo di (nh cc u d o in tr, u d o in tr phn cc, u d siu m). Theo di offl ine nhm xc nh mc h hng xy ra v thng s dng cc k thut kim tra khng ph hy (non-destructive testing - NDT) nh kim tra trc quan, siu m Cc bin php bo v chng n mn trong cc cng trnh du kh hin nay v nguyn tc vn da trn cc phng php truyn thng:

s dng cht c ch, bo v bng phng php in ha, s dng lp ph.

Cc k thut theo di, bo v chng n mn trn l mt trong hai thnh phn ca mt h thng qun l n mn hon chnh. Tuy nhin, do nhn thc cha y v chnh xc v h thng ny m cc nh my ch tp trung thc hin k thut chng n mn (CE) m khng quan tm trin khai qun l n mn (CM) cho ton b cng trnh, nn kt qu vn hnh ca h thng ny cha t hiu qu nh mong mun v c th tim n ri ro ln. Do vy, nhm tc gi cho rng cn xy dng hng dn thc hin qun l, kim sot n mn cho cc cng trnh/nh my ch bin du kh, nhm nng cao hiu qu vn hnh v gim thiu ri ro do n mn gy ra, bo m an ton ti a v tit kim chi ph bo dng sa cha. Trong bi bo ny, nhm tc gi gii thiu hng dn xy dng h thng qun l n mn chung cho nh my theo cc bc (Hnh 1) [4], ng thi a ra v d c th v hng dn qun l n mn do tip xc v hng dn qun l h thng bo v chng n mn bng phng php s dng lp ph.

2. Hng dn xy dng h thng qun l n mn chung cho nh my

2.1. Xy dng chnh sch v chin lc qun l n mn

Chnh sch v chin lc qun l n mn l mt phn ca chnh sch tng th v hot ng ca t chc v phi ph hp vi chnh sch chung ny. Chnh sch cn c xy dng nhm i ph vi mi ri ro lin quan n an ton sc khe v mi trng cng nh cc ri ro lin quan n li nhun kinh doanh. Chnh sch s a ra chin

HNG DN QUN L, KIM SOT N MN CHO CC CNG TRNH CH BIN DU KH

ThS. Nguyn Xun Trng, ThS. Phan Cng Thnh ThS. ng Th Tng, ThS. Nguyn Ngc Dip Vin Du kh Vit Nam

Tm tt

H thng qun l n mn ng vai tr quan trng trong vic gp phn nng cao tui th ca thit b, duy tr hot ng lin tc v gim thiu chi ph qun l, bo dng v sa cha thit b trong cng nghip ch bin du kh. H thng qun l n mn thit b, cng trnh gm 2 thnh phn ch yu: qun l n mn (CM) v k thut chng n mn (CE) [1]. Qua kho st mt s nh my ch bin du kh Vit Nam, nhm tc gi nhn thy cc nh my xy dng h thng qun l n mn, tuy nhin mi tp trung vo cc bin php bo v chng n mn m cha ch trng n vic qun l cc bin php bo v chng n mn v cc dng n mn. Bi bo gii thiu hng dn xy dng h thng qun l n mn cho cc nh my ch bin du kh trn 3 phng din: Hng dn qun l n mn chung cho nh my; Hng dn qun l cc bin php bo v chng n mn; Hng dn qun l cc dng, nguy c n mn c th xy ra trong nh my ch bin du kh.

T kha: H thng qun l n mn, k thut chng n mn.

AN TON MI TRNG DU KH

66 DU KH - S 3/2014

lc, cu trc t chc, tiu chun thc hin, quy trnh v cc trnh t qun l, trong nu r: mc tiu, i tng p dng chnh sch v cch thc thc hin phi c s ng thng qua ca lnh o. Chin lc s cung cp phng tin gip thc hin chnh sch.

C nhiu phng php khc nhau thit lp chnh sch qun l n mn. Mt s t chc thit lp, vn hnh h thng qun l n mn thng qua nhm chuyn vin ni b v nhm ny c nhim v lp v pht trin chnh sch, chin lc chng n mn. Mt s t chc khc li mi nh thu bn ngoi lp chnh sch v chin lc chng n mn, sau c t chc ph duyt. Cng vic c th c thc hin trn gi, hoc cng c th mi nhiu nh thu thc hin tng cng vic ring bit, bao gm: thit lp h thng v quy trnh; kim sot qu trnh vn hnh h thng; kim tra, kim sot vic thc hin.

2.2. C cu t chc v phn cng trch nhim trong qun l n mn

Cng tc qun l n mn c lin quan n rt nhiu b phn trong cu trc qun l. V vy, cn xc nh r

vai tr, trch nhim v nng lc ca tng c nhn xy dng mt cu trc qun l n mn ph hp.

- Vai tr, trch nhim trong t chc: Phn nh r vai tr, trch nhim v quyn hn k thut ca cc thnh vin trong vic ln k hoch v thc hin cc hot ng qun l n mn. Mi n v c c cu t chc khc nhau, tuy nhin mt s v tr ch cht cn phi c l: qun l vn hnh chung; trng nhm thit k v bo dng; trng nhm qun l thit b; k s ph trch thit b; k s kim tra thit b; trng nhm n mn v vt liu; k s n mn v vt liu; k s cng ngh ha hc; k s sn xut; ph trch qun l sn xut; k s vn hnh; ph trch theo di vn hnh thit b. Mi lin h gia cc v tr ny c th hin Hnh 2.

- Nng lc thc hin: Cn c chnh sch v chng trnh o to c th cho cc i tng chu trch nhim vn hnh m bo pht huy vai tr nng lc ca mnh v pht trin cc k nng x l. i vi nhng v tr quan trng nh ph trch k thut cn nm r iu kin vn hnh thit b, c kin thc v cc tiu chun, k thut n mn trong qun l n mn. Trng nhm qun l thit b phi c kin

thc v hiu v vai tr, trch nhim v cu trc qun l n mn trong t chc; c kinh nghim vn hnh thit b, nh gi ri ro n mn v cc k thut qun l n mn; c kin thc v cc phng php kim tra, p dng v phng php o to nh gi thch hp K s vt liu, n mn phi am hiu v tnh cht, c tnh v ng dng vt liu, la chn v ng dng cc k thut theo di, kim tra, chng n mn. Cc v tr khc u cn p ng c yu cu ca cng vic. Yu cu tng ng hoc tt hn tiu chun k thut c ngnh cng nghip hoc quc gia cng nhn.

- S trao i thng tin trong v ngoi t chc phi c x l kp thi, ng ngi, ng thi im. Nhm qun l n mn thc hin truyn ti thng tin vi cc bn, t chc; thc hin thng xuyn cc cuc hp thng bo tnh hnh thc hin, cc h hng xy ra v hnh ng khc phc. Cn c s trao i thng tin vi cc b phn gin tip

Tiu ch: - m bo an ton, sc khe v

tnh ton vn ca thit b - Gim thiu n mn

Xy dng chnh sch v mc tiu r rng trong qun l n mn

Xy dng c cu t chc v phn cng trch nhim

nh gi ri ro n mn v ln k hoch thc hin

Trin khai cc hot ng theo k hoch v phn tch kt qu

Theo di v nh gi vic thc hin da trn cc tiu ch xc nh

Kim tra li vic thc hin mt cch c h thng v u n

p ng cc tiu chun

Kim tra c lp i vi h thng qun l v theo di n mn

Bo co nhm ci tin, nng cp h thng qun l n mn

Hon thin h thng

Kim tra li a ra nhng hnh ng khc phc

C

Khng

Hnh 1. Lu m t trnh t cng vic trong mt h thng qun l n mn

PETROVIETNAM

67DU KH - S 3/2014

nh b phn thit k v vn hnh, ti chnh, nhn s v qun l h tr vic qun l n mn. Cn ch ti b phn lm vic trc tip. y l b phn nm r hot ng ca cng trnh nht. S tham gia ca h rt quan trng c bit khi ni n n mn bn ngoi. Cc phng thc trao i thng tin vi b phn ny c th l: cc cuc hp v an ton, poster c ng, bng tin, t ri, video, cc bui gii thiu o to v nhn thc n mn cho b phn trin khai trc tip cn phi tp trung vo vic nhn ra nhng vn do n mn gy ra v nhng hng dn vo nhng im quan trng. Cn c trao i thng tin gia cc t chc vi nhau, vi cc nh thu khc c thm kinh nghim, hiu bit v s h tr.

- S hp tc gia cc thnh vin: Nhm qun l n mn l mt b phn rt quan trng trong pht trin vic hp tc. Nhm qun l n mn ph trch quy trnh qun l n mn v thc y vic hp tc nhm gip h thng qun l n mn c hot ng c hiu qu.

2.3. nh gi ri ro n mn v ln k hoch

Bc cng vic ny gip xc nh cc nguy c n mn, nh gi v xp loi mc ri ro, t ln k hoch ph hp ngn nga v lm gim nguy c n mn mt cch hiu qu bng cch tp trung vo nhng v tr c mc ri ro cao, trnh vic tn km thi gian v nhn lc vo nhng ni c ri ro n mn thp. nh gi ri ro n mn c th thc hin ngay t khu thit k, trn c s nghin cu l thuyt v kinh nghim. Sau , trong qu trnh vn hnh thit b, cng tc nh gi ri ro n mn s c xem xt kim tra li v thay i theo iu kin thc t. Vic xy dng k hoch thc hin cn c tin hnh c 2 cp: cp chin lc (la chn phng php bo v chng n mn) v cp trin khai (xc nh v tr cn bo v v theo di hiu qu bo v.

- nh gi ri ro n mn gm: xc nh v ghi li hng mc, thit b c kh nng b n mn; xc nh cc nguy c n mn nh hng n cc b phn quan trng c kh nng dn n h hng thit b; xc nh v nh lng cc hu qu do h hng gy ra. Mc tiu ca nh gi ri ro n mn nhm phn loi cc thit b tnh theo ri ro n mn v cc bin php c th loi tr v lm gim hoc qun l ri ro . Trong qu trnh vn hnh thit b,

nh gi ri ro n mn l hng hot ng theo di v kim tra n mn vo cc h hng c bit trc v pht hin cc h hng mi. nh gi ri ro n mn c coi nh bc u tin ca h thng phn tch da trn c s phn tch ri ro RBI (risk based inspection). Ri ro n mn thng c biu din bng tch ca kh nng xy ra h hng do n mn v hu qu ca n. Trong , kh nng xy ra h hng c nh gi da trn dng h hng c th xy ra do n mn; hu qu do h hng gy ra c o c da trn tc ng ca h hng trn mt s lng tiu chun, bao gm t nht: nhng tc ng i vi an ton, mi trng, vn hnh, c th dn n mt mt vt cht.

- Xy dng chin lc v k hoch thc hin chi tit. V chin lc, cn xc nh cc v tr, hng mc, thit b cn bo v khi n mn; xc nh cc nguy c n mn c th xy ra; hu qu khi xy ra cc h hng; la chn phng php theo di, lm gim n mn v phng php nh gi hiu qu cc bin php ; xc nh tn sut theo di n mn; phn cng trch nhim theo di n mn; xc nh cc hnh ng khc phc khi khng t yu cu. Khi xy dng k hoch chi tit, cng c c s dng chnh l phng php phn tch trn c s phn tch ri ro RBI vic kim tra n mn c ln k hoch v thc hin nhng v tr thch hp. RBI s dng cc d liu thu thp c t cc nh gi v ri ro n mn, nh hng cho k hoch kim tra v quy trnh kim tra.

Vic thc hin phn tch ri ro nhm: m bo gim thiu ti a cc ri ro; ti u ha qu trnh kim tra; tp trung kim tra vo nhng v tr c nguy c cao nht; xc nh cc phng php kim tra thch hp nht.

Hnh 2. Mi lin h gia cc v tr trong t chc

Bo co

D liu

Trng nhm n mn & vt liu

K s vn hnh

Trng nhm qun l thit b

K s n mn & vt liu

Thng tin bo dng

Kt qu kim tra nh gi

K s ph trch thit b

K s sn xut

Theo di on-line

Thng tin sn phm

D liu gim st quy trnh sn xut

D liu vn hnh

D liu thit k

Chuyn vin x l ha hc


68 DU KH - S 3/2014

2.4. Thc hin v phn tch

thc hin thnh cng cc k hoch ra i hi vic s dng cc ngun lc v thit b v nhn lc mt cch hiu qu cng vi vic tun th trit hng dn thc hin (Hnh 3).

2.4.1. Thc hin

- Xy dng hng dn thc hin: Cc quy trnh dng vn bn v cc hng dn thc hin c xy dng thnh cc dng ti liu khc nhau, bao gm: h s k hoch bo tr, bo dng; hng dn vn hnh v cc o c trong h thng iu khin nh my. Trong , h s k hoch bo tr, bo dng c ln k hoch chi tit: danh mc cc thit b, b phn c bo dng; chu k bo dng, thi gian tin hnh bo dng cho tng thit b; hng dn thc hin bo dng; bo co v hot ng bo dng; lch s nhng bt thng xy ra; ti liu tham kho, v d nh cc kt qu o cc thi im khc nhau xc nh hng kho st; s ng i v lu gi ti liu bo dng. thun tin hn trong cng tc qun l, c th lp trnh phn mm qun l k hoch bo tr, bo dng.

- Hng dn vn hnh v cc o c trong h thng iu khin nh my. Cc hng dn phi c cung cp cho cc k thut vin vn hnh v a ra cc bc phi thc hin trong trng hp gii hn b vt qu do k thut o hay do h thng iu khin nh my bo ng. iu khin hot ng ca cc thit b, h thng iu khin phn tn (DCS) thng c s dng bng cch

kt ni qua mng li giao tip v gim st. Trong mt s trng hp, DCS c th c lp trnh phn ng i vi nhng tham s vt qu gii hn. Cc d liu do DCS thu thp c s a vo b c s d liu v lu trong mt khong thi gian nht nh.

- Cc bin php lm gim n mn v theo di n mn. Bin php ch ng c xc nh t trc cc yu cu theo di, kim tra cc bin php theo di v lm gim n mn, thc hin trc khi pht hin ra bt k h hng hay hin tng n mn no. Thng l trong trng hp khi vic nh gi ri ro n mn v k hoch cp chin lc xc nh cc tiu chun thc hin gip gim n mn mt cch c hiu qu hoc xc nh cc ph hy cho php. Cc bin php tc ng c thc hin trong trng hp pht hin c vn xy ra.

Lm gim n mn l hot ng ch ng, c trin khai sau khi c cc nh gi ri ro ban u khu thit k, gm cc bin php: s dng hp kim chu n mn, lm kh kh, dng ha phm, sn ph, bo v cathode... Trong mt s trng hp, lm gim n mn c th l hot ng c tnh cht tc ng, cc bin php mi thc hin khi cc bin php ch ng khng t kt qu hoc khi c c ch n mn mi xut hin. y thng l mt dng ca hnh ng khc phc.

2.4.2. Thu thp d liu, bo co, phn tch v hnh ng khc phc

- Thu thp v lu d liu: thu thp d liu c bn t cc ngun khc nhau (nh: t DCS, t ghi chp ca

ngi vn hnh, t cc bo co v h hng vt liu v n mn, t cc thit b theo di n mn). Khi thu thp d liu t bo co cn lu : khi cc gi tr o c vt qu gii hn cho php th phi ghi li v bo li cho b phn ph trch sm nht c th a ra cc hnh ng kp thi; i vi nhng d liu c mc khn cp th phi c hnh thc bo co c bit ngn chn h hng xy ra. Trong qu trnh ln k hoch v thc hin, cn lu n vn lu d liu (bn mm v bn cng), qun l v phn tch d liu. Cng tc lu tr d liu phi m bo: d

Thc hin

Trin khai cc bin php chng n mn v theo di n mn, cc t kim sot n mn theo k hoch

a ra cc hng dn thc hin cng vic

Thu thp d

liu

Cc bo co v bo tr bo dng Cc d liu v kim sot v theo di n mn Cc bo co v trng hp khn cp, v cc ph hy do n mn

Phn tch

Qun l cc ngun thng tin nh gi, nhn dng cc hnh ng khc phc a ra cc xu hng, suy on Tin hnh phn tch nguyn nhn ct li

Bo co

Bo co nh k hng tun/thng/qu/nm v tnh hnh vn hnh Bo co cho nhm qun l n mn v cho cp lnh o

Hnh ng khc phc

Tng lng ha phm x l

Tng cng h thng bo v cathode, bo dng lp ph

Thay th cc b phn hoc vt liu

nh gi li cc yu cu v theo di v kim sot n mn cng vi chu k ca chng

Hnh 3. Cc bc thc hin h thng qun l n mn

PETROVIETNAM

69DU KH - S 3/2014

dng kim sot v tm kim d liu; ngi vn hnh thit b c trch nhim trong vic lu d liu v lm ch d liu; thun tin truyn d liu t nh thu n ngi vn hnh v t nh thu n nh thu.

- Phn tch d liu: Cc d liu theo di v kim tra n mn c th c sai s (do s hn ch ca thit b, s bin thin ca cc thng s lin quan n con ngi v n mn), do cn phi lu n tin cy ca d liu khi nh gi xu hng n mn. Khi thu thp c s liu kim tra bt thng cn xt n cc kh nng do: s thay i trong iu kin vn hnh, sai st trong qu trnh s dng thit b kim tra n mn hoc nhp sai d liu.

- Hnh ng khc phc: Sau khi cc d liu kim tra, theo di v bo v chng n mn c thu thp v phn tch, cn phi xc nh v trin khai cc hnh ng khc phc cn thit. C 3 loi hnh ng khc phc: bo v tm thi, hnh ng khi phc, hnh ng ci tin. Vic la chn hnh ng ph hp da trn loi thit b v bn cht v mc ca h hng. Tc ng v mt kinh t v tnh thc t ca nhng s la chn trn ph thuc vo tui th ca thit b nh thit b mi xy dng, qua sa cha hoc qua s dng lu di. Mt s hnh ng khc phc c th c thc hin nhanh chng trong khi mt s khc, c bit l cc hnh ng mang tnh ci tin s

mt mt khong thi gian nht nh trin khai. Cc bi hc kinh nghim v cc thng tin c lin quan cn phi c phn hi v h s nh gi ri ro n mn.

- Kim tra h hng v phn tch nguyn nhn ct li

- Nu c h hng nghim trng xy ra hoc c nhng sai st trong thc hin m cha c sa cha th c th s dng phng php phn tch nguyn nhn ct li m bo hnh ng khc phc s gii quyt trit . Vic tm hiu nhng h hng do n mn v vt liu cn phi gii p c: c ch h hng l g; cc bin php phng chng h hng v ti sao cc bin php ny li khng c tc dng; cc bin php theo di hiu qu bo v ca cc bin php v ti sao vic theo di ny khng pht hin c h hng; tiu chun thc hin c ph hp khng; ai c trch nhim trong vic trin khai cc bin php chng n mn v bin php theo di n mn.

Vic s dng k thut phn tch nguyn nhn ct li s gip chuyn vin qun l n mn i ng hng, c ci nhn khch quan v c lp. Quy trnh phn tch nguyn nhn ct li (Hnh 4) phi c xy dng bi chuyn gia c nng lc v hiu bit v qun l n mn. Trnh t cc bc phn tch nguyn nhn ct li: thit lp c ch ph hy do n mn ca thit b; da vo hng dn v cc bc phn tch nguyn nhn (nh trong v d) thu

thp cc d liu v thit k, bo dng, kim tra v tm hiu nguyn nhn ca h hng; nh gi chi tit cc nguyn nhn tm ra nguyn nhn su xa hn; lp bo co tng hp nhng nguyn nhn trong bao gm c cc thiu st trong h thng qun l (nu c).

2.5. Theo di v o c hiu sut thc hin

y l bc cng vic cn thit v thc hin kim tra 2 vn : cc hnh ng cn Hnh 4. S phn tch nguyn nhn ct li

S dng sai k thut

S dng sai quy trnh

Yu t con ngi

- nh gi ri ro s si - Thiu thng tin v thit b - Yu t v t chc

- Thiu s trao i thng tin - Ngun thng tin khng y - B mt khng ph hp cho kim tra n mn

Yu t con ngi

Thay i quan trng trong thng s vn hnh

Thay i quan trng trong thnh phn ca cht lng

Thay i quan trng trong nh my

Khng t c s duy tr

p sut, nhit , tc

CO2, H2S, mui, phn t, vi

Nhng thay i khng

- Phng chm ca t chc - Cam kt v nhn thc - Yu t ngun lc

Xut hin n mn

Sai st trong vn hnh

Sai st trong thit k

Sai st trong kim tra n mn

Sai st trong bin php chng n mn

Khng c kim tra

Thiu kim tra Sai st trong s dng

lp ph

Sai st trong vic bm ha phm

Lp ph c c tnh k thut thp

Lp ph khng c duy tr

p dng cha ng

S dng qu nhiu ha phm

- Ha phm khng dn n thit b chu n mn

- Khng theo di c vic bm ha phm hoc c khng bm ha phm

S dng sai ha phm

Thit k to iu kin cho n mn xut

hin

S dng sai vt liu

Kim sot cht lng yu km

C vn v nng lc v nhn thc

Cc sai st khc

Khng p ng QA/QC

p lc t lnh o

Sai c tnh k thut

Ngi thit k thiu nng lc

Vn ha doanh nghip thp


70 DU KH - S 3/2014

thit c vch ra trong chnh sch, chin lc v k hoch c c thc hin hay khng; kt qu c t c nh mong mun hay khng. Quy trnh kim tra gm 4 bc sau: thit lp cc bc o c hiu sut thc hin; xc nh trch nhim trong mi cng vic; xc nh tn sut o c; thit lp cc hnh ng khc phc.

- o c (kim tra) hiu sut: Ch s hiu sut i vi h thng qun l n mn cn phi c xc nh ngay t khu ln k hoch, da trn mc tiu nu ra trong chnh sch v chin lc. t c mc tiu th ch s hiu sut cn phi o c, c kh nng t c v c tnh thc t.

- Xc nh trch nhim: Hot ng ny c lin quan n vic xem xt kim tra li quy trnh qun l nn trch nhim xem xt li quy trnh o c hiu sut cn phi thuc v nhng c nhn khng chu bt k p lc no v sn xut v khng c trch nhim no trong vic thc hin quy trnh cn nh gi. Trch nhim thc hin c th c phn vng nh sau: trch nhim trong vic xy dng cc tiu chun thc hin khi trin khai bin php bo v chng n mn, d liu do nhn vin vn hnh cung cp, k s n mn kim tra li; trch nhim trong vic trin khai cng tc kim tra n mn theo k hoch, d liu do nhn vin kim tra cung cp, k s ph trch thit b kim tra li; s lng cc h hng, nh hng n mi trng, thu thp v bo co di s kim sot ca qun l an ton.

- Xc nh tn sut o c: nhng hnh ng khc phc c p dng kp thi, tn sut o c hiu qu ca cc bin php bo v chng n mn phi c xy dng t lc ln k hoch. Tn sut o c hiu sut trong qun l l khc nhau i vi mi cng ty, mi t chc v ph thuc vo mc tin cy v n nh ca d liu thu c. Tn sut cng ph thuc vo tng thit b v quy trnh.

- Hnh ng khc phc gm: sa cha bm, sa cha nhng r r, tng s phn b cc v tr bm ha phm, ngoi ra cn tip tc nng cao trnh ca nhm ph trch thc hin, trong c o to, nng cao nhn thc i vi mi ln kim tra li vic o c hiu sut thc hin, cn phi a ra nhng bo co cho nhm thc hin kim tra v theo di n mn, cho cc cp lnh o v nhng ngi qun l thit b. Trong bo co c th xp loi ch s hiu sut thc hin nhng ngi c trch nhim x l s tp trung vo nhng vn quan trng.

2.6. Kim tra hiu sut thc hin

Vic kim tra li cc bc thc hin s rt ra nhng bi hc, t gp phn ci tin, nng cao hiu qu thc hin

trong cc ln tip theo. Vic kim tra li ch kim tra trn l thuyt hiu sut trin khai h thng qun l n mn, khng kim tra chi tit v mt k thut i vi cc d liu theo di, kim tra v bo v chng n mn.

Vic kim tra li gm: kim tra li cc thng s o c ch ng v tc ng; kim tra li cc h hng ln ca h thng v nh hng ca chng; kim tra li tnh trng ca thit b; kim tra li hiu qu qun l cc hnh ng khc phc; kim tra nh hng ca cc thay i trong thit k v sn xut i vi thit b; kim tra li hiu qu ca h thng trong vic chia s bi hc kinh nghim v trao i thng tin vi cc nh vn hnh khc.

Tn sut kim tra li ph thuc vo bn cht ca thit b v quy trnh vn hnh cng nh hon cnh vn hnh. Thi gian thc hin kim tra ln tip theo phi c ln k hoch ngay t ln kim tra trc. Khong cch gia 2 ln kim tra ph thuc vo hiu qu v s n nh trong vn hnh ca h thng qun l n mn.

Hnh thc kim tra li thng xuyn nht l vic t chc cc cuc hp nhm qun l n mn vi tn sut khong t 1 - 3 thng/ln, ph thuc vo s n nh ca cc hot ng kim sot n mn. Trong cuc hp ny, nhm s xem xt qua vic thc hin cc hot ng vn hnh gip duy tr cc bin php chng n mn (nh c ch, kim sot vi khun, lm kh kh, bo v cathode), r sot cc quy trnh qun l chnh nh cc hot ng kim sot n mn v vic qun l hnh ng khc phc.

Trong trng hp c yu cu thay i trong sn xut kinh doanh t xut, nm ngoi k hoch th cn tin hnh kim tra li : xc nh xem thit b no s b nh hng; xc nh thay i no s c thc hin; phn hi thay i n cc c nhn c lin quan nh gi tc ng tim tng v xc nh nhng thay i cn thit cho quy trnh.

2.7. nh gi h thng

nh gi h thng a ra quan im v s ph hp ca h thng qun l n mn so vi yu cu. Kim sot thc hin i vi vic trin khai h thng qun l n mn v thng c bn th ba thc hin. Kim sot s kim tra li ton b quy trnh qun l ang c p dng m bo tnh lin tc ca h thng v tnh trng hot ng ca thit b. Kim sot s kim tra cc quy trnh dn n vic t c mc tiu v nh gi xem cc quy trnh c c thc hin thch hp hay khng, t , nhng hot ng khng ph hp s c xc nh.

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3. Hng dn qun l dng n mn tip xc (n mn galvanic)

n mn galvanic l dng n mn xut hin ti v tr tip xc gia cc kim loi khc nhau trong mi trng in ly. Kim loi tr hn (cathode) c bo v do kim loi m hn ng vai tr l anode hy sinh b n mn. n mn tip xc xy ra khi: mi trng dn in (dung dch in ly); hai kim loi khc nhau tip xc vi mi trng dn in (c th l cp hai kim loi khc nhau, kim loi - phi kim hay kim loi - hp cht, kim loi c th in cc chun nh hn l cc m); c dng in gia 2 kim loi. Cc yu t nh hng n tc n mn tip xc bao gm: s chnh lch in th gia hai kim loi, din tch tip xc gia 2 kim loi v t l anode/cathode. T l ny cng thp th tc n mn anode cng cao.

n mn tip xc l mt vn ng quan tm i vi h nc bin a kh, v vy cn trnh s dng nhiu loi hp kim khc nhau. Trong mi trng sn xut, dng n mn ny t xy ra hn do tnh dn in trong pha nc thp hn.

3.1. Chnh sch v chin lc

Cc chnh sch v an ton, mi trng v thng mi c nh hng n s la chn phng php theo di, kim sot v bo v chng n mn. Mt s chin lc bo v chng n mn nh sau:

- Phng php bo v u tin t khu la chn vt liu ph hp. T khu thit k ban u, cn nhn dng v loi b cc nguy c tim tng. Bt k s thay i hoc nng cp vt liu no cn phi tnh n kh nng xy ra n mn tip xc;

- Trnh s tip xc gia anode nh v cathode ln;

- C lp in ha khi c s tip xc gia 2 kim loi khc nhau;

- Lp t h thng bo v cathode bn trong;

- Lp t cc m gia cc kim loi khc nhau sao cho khong cch tip xc gia 2 kim loi t 10 - 20 pipe. m c th l vt liu khng dn in dng rn v d nh nha gia c thy tinh (GRP), hoc kim loi tr hn trong cp kim loi c ph bn trong bng vt liu khng dn in nh cao su;

- a ra 1 gii hn n mn cho php (ngay t khu thit k) i vi kim loi t tr hn;

- Phng php kim tra trc quan v siu m c th c s dng pht hin n mn tip xc.

3.2. T chc

Cc chuyn vin v n mn v vt liu, gip a ra yu cu k thut v vt liu v nhn dng cc ri ro tim tng lin quan n n mn tip xc. K s vn hnh thit b. Nh thu trin khai k thut kim tra khng ph hy v k s kim sot n mn gip kim tra, thu thp d liu. iu quan trng l cn phi c s trao i thng tin nhm nng cao hiu bit v cc yu t nh hng n n mn tip xc trnh nhng sai st nh s dng sai vt liu cho mt bch v inh c hoc s dng cc u ni ng ng bng cc kim loi khng ng nht

3.3. nh gi ri ro n mn v ln k hoch thc hin

Trong qu trnh xy dng chin lc v k hoch thc hin cn xc nh: cc bin php bo v chng n mn hin s dng; cc bin php theo di v chu k theo di; hnh ng khc phc kp thi trong trng hp c s khng ph hp; trch nhim ca t chc trong vic theo di, bo v v thc hin hnh ng khc phc.

Vic xy dng k hoch chi tit gm: p dng quy trnh qun l s thay i khi tin hnh thay i hoc nng cp vt liu; xc nh cc bc RBI; ln chng trnh bo tr c k hoch; dch v kim sot v theo di n mn, bao gm phn cng trch nhim, phi hp, quy trnh, phm vi cng vic.

3.4. Thc hin v phn tch

Vic thc hin cn tun theo k hoch xy dng trc. Vic kim tra n mn bn trong bng phng php trc quan l rt cn thit xc nh n mn tip xc. Vic thu thp d liu v n mn tip xc c thc hin bng nhiu cch nh: cc d liu kim sot c cc chuyn vin ghi chp li y di dng bo co v c nhp vo c s d liu song song vi vic ti d liu t cc thit b o NDT; so snh ban u vi cc c tnh k thut ca vt liu v ng ng xc nh s cn thit ca hnh ng khc phc; kim tra li nhng thay i, b sung so vi c tnh k thut ban u ca ng ng; phn tch tt c cc d liu, thng l do cc k s n mn thc hin, m bo rng cc mc tiu trong k hoch v chin lc c p ng v vic nh gi ri ro n mn v ln k hoch thc hin c ci tin nng cp cho ph hp.

3.5. Theo di v o c hiu sut thc hin

Ch s o c ch ng s nh gi mc hon thin ca cc hot ng kim tra n mn so vi k hoch. Ch s o c tc ng s theo di tn sut xy ra r r do n mn tip xc gy ra.


72 DU KH - S 3/2014

3.6. Kim tra hiu sut thc hin

Hng nm, xem xt kt qu theo di, kim tra n mn v cc bin php chng n mn; s dng hnh ng khc phc nu cn thit. Xem xt cc bin php thc hin, c bit l vic nh gi cc ch s tc ng v xu hng tng th trong cc ch s ch ng. Xem xt sa i, ci tin trong chin lc, t chc v k hoch nu cn thit. Phn tch nguyn nhn ct li ca cc h hng do n mn tip xc, s dng cc hnh ng khc phc thch hp. T , a ra nhng thay i, ci tin cho ph hp.

4. Hng dn qun l bin php s dng lp ph chng n mn

S dng lp ph l gii php c bn bo v chng n mn, thng c s dng bo v chng n mn trong mi trng nc bin v ti cc nh my ch bin du kh. Hu ht cc lp ph c s dng di dng lp mng bng vt liu nha hu c c cha cc nn mu v c v dung mi hu c. Thng thng lp ph gm 3 lp: lp nn c ch n mn, lp th 2 tng chiu dy v lp trn cng to cm quan. Mt s lp ph khng cha dung mi, dng di dng phun sng hoc trowel c s dng rt nhiu bo v n mn bn trong. Chiu dy lp ph s ln hn v thng ch c t 1 - 2 lp. Dng lp ph ny c p dng trong mi trng c nhit cao. Nu nh trc y cc ng ng s dng sn ph c cha than v bitumen cha x, th hin nay s dng sn nhiu lp c epoxy v cc lp nha do.

Mt s nguyn nhn khin lp ph b ph hy nh: s xm nhp ca nc qua mng sn (bng phng php thm thu), gy ra g v v lp sn; cc tia UV trong nh sng mt tri lm hng lp nha hu c; cc dung mi v ha phm lm hng lp sn. V vy khi s dng sn ph cn chun b b mt tt trc khi sn s gip loi b c cc tp cht v gip cho cht lng bm ca sn tt hn; khi thit k trnh nhng cnh sc hoc b mt rp v cc v tr kh tip cn.

Ngoi ra lp sn ngoi cng to cm quan cng ng vai tr quan trng trong vic bo v b mt kim loi. Sn ph cng c th c s dng cng vi phng php bo v cathode. Trong trng hp ny c th chp nhn nhng bong trc nh nhng i hi phi s dng sn c kh nng chu c pH cao hn ti v tr cathode. Mt s lp ph c dy ln c s dng chng chy.

- Chnh sch v chin lc

Chi ph bo dng cc lp ph bn ngoi tng i

cao, do cn c bin php ti u gia cht lng ca lp ph ban u v chi ph bo dng lp ph sau ny. Phng php bo dng lp ph: bo dng theo cc bo co v kim tra lp ph v kho st tnh trng lp ph; xy dng k hoch bo dng da trn vic kho st v d on v kh nng bong trc lp ph; theo di tnh trng ca b mt kim loi, sau ch bo dng lp ph khi gi tr mt khi lng c xu hng tin dn n gii hn cho php; sa cha, thay th thit b khi gi tr mt khi lng vt qu gii hn v khng cn phi bo dng lp ph na.

Vic thc hin cc bin php bo dng lp ph cn phi tnh n nhng yu cu kht khe trong vic chun b b mt v sn ph khi la chn phng php, vt liu; h hng v nhim bn cho mi trng nh my; cc kh khn khi lm vic trong mi trng c nhit cao, nguy c chy n. Thng thng nhng v tr bn trong kh tip cn hay ngm di nc th ngi ta thng s dng lp ph c tui th cao v t khi phi thay th. Vic chun b b mt v sn ph phi c kim sot cht lng cht ch: sch b mt kim loi; chiu dy mng sn; iu kin v nhit v m.

- T chc

Cc i tng lin quan n cng vic: chuyn vin v n mn v vt liu; nh cung cp vt liu sn ph; nh thu ln k hoch bo dng lp ph; nhm bo dng thit b; k s kim sot n mn; k thut vin kim sot lp sn ph. Cn phi c trao i thng tin nhm nng cao nhn thc v cc yu t nh hng n s ph hy ca lp ph v tm quan trng ca vic trin khai cc bin php bo dng lp ph.

- nh gi ri ro n mn v ln k hoch thc hin

K hoch qun l cc bin php bo v chng n mn bng lp ph c xy dng trn c s: mc tiu thc hin, thng thng trn phng din kh nng bong trc ca lp ph; theo di bng vic kho st cm quan v chu k kho st; cc hnh ng khc phc trong trng hp c s khng ph hp; trch nhim ca t chc trong vic theo di, kim sot v bo v chng n mn.

Khi xy dng k hoch thc hin chi tit, cn phi hon thin: chng trnh bo dng lp ph, da trn nh gi ri ro; chng trnh bo tr c k hoch trong vic bo tr lp ph; dch v kim sot v theo di n mn, bao gm phn cng trch nhim, phi hp, quy trnh, phm vi cng vic.

- Thc hin v phn tch

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Vic trin khai bo dng v kho st lp ph cn phi c thc hin theo k hoch. Cc d liu thu thp c gm thi gian v phm vi ca lp ph kt hp cc d liu kho st tnh trng lp ph nhm nh gi mc bong trc ca lp ph. Vic phn tch d liu thc hin thnh hai bc: (1) phn tch tnh trng lp ph so vi mc tiu xc nh s cn thit phi ln k hoch bo dng lp ph trnh n mn xy ra; (2) phn tch tt c cc d liu, thng l do cc k s n mn thc hin, m bo cc mc tiu trong k hoch v chin lc c p ng v vic nh gi ri ro n mn v ln k hoch thc hin c ci tin nng cp cho ph hp.

- Theo di v kim tra vic thc hin

Cc ch s ch ng gm: s hon thin ca vic bo dng lp ph so vi k hoch; s lng cc h hng vt qu gii hn ph hy; s hon thin ca vic kho st lp ph so vi k hoch. Cc ch s tc ng gm s ph hy ca lp ph sm hn so vi tui th d kin.

- Kim tra hiu sut thc hin

Xem xt thng xuyn kt qu theo di, kim tra n mn v cc bin php chng n mn, s dng hnh ng khc phc nu cn thit. R sot cc bin php thc hin, c bit l vic nh gi cc ch s tc ng v xu hng tng th trong cc ch s ch ng. Tin hnh phn tch nguyn nhn ct li ca cc h hng i vi lp ph, s dng cc hnh ng khc phc thch hp. a ra nhng thay i, ci tin cho ph hp.

5. Kt lun

H thng qun l n mn c xy dng ph hp vi

tnh cht cng vic ca nh my ch bin du kh, c th c vn hnh mt cch a dng cc cp qun l v k thut trong mt t chc. Mc a dng v phc tp ca h thng ph thuc vo quy m ca nh my, s lng nhn vin, vai tr v trch nhim ca ngi qun l, k s, k thut vin v cc nh thu.

Kinh nghim thc t chng minh rng vic pht trin mt h thng qun l n mn hiu qu, cng vi cam kt thc hin ca ngi lnh o cng nh cc nh thu, gip nng cao ng k mc an ton trong qu trnh vn hnh ca nh my v gim thiu ri ro cho thit b v con ngi, c bit khi h thng ny c theo di v cp nht thng xuyn.

Ti liu tham kho

1. Ali Morshed. Corrosion management for oil and gas assets. Chemical Treatment. 2008: p.54 - 59.

2. Chinedu I.Ossai. Advances in asset management techniques: An overview of corrosion mechanisms and mitigation strategies for oil and gas pipelines. Review Article, ISRN Corrosion. 2012.

3. ASM International. Corrosion in the petrochemical industry. 1994.

4. Energy Institute, London. Guidance for corrosion management in oil and gas production and processing. May 2008.

5. NACE International. Techniques for monitoring corrosion and related parameters in fi eld applications. 2008.

Summary

The corrosion management system has long been considered to be a useful tool in enhancing asset life, increasing plant availability and reducing costs for unplanned maintenance and repair. A corrosion management system con-sists of two major components: corrosion management and corrosion engineering. Many petroleum plants in the world have set up their corrosion management system at diff erent scales, including the application of up-to-date technologies for corrosion mitigation. A survey at some petroleum plants in Vietnam has shown that the plants have established for themselves a corrosion management system, however they only focus on the installation of corrosion mitigation barriers while the management of corrosion mitigation methods and corrosion threats has not been suf-fi ciently considered. This article presents a guidance for corrosion management in oil and gas processing plants in three aspects: guidance for corrosion management, guidance for corrosion mitigation methods management and guidance for corrosion threats management.

Key words: Corrosion management system, corrosion engineering.

Guidance for corrosion management in oil and gas processing plantsNguyen Xuan Truong, Phan Cong Thanh, Dang The Tung, Nguyen Ngoc Diep Vietnam Petroleum Institute

Documents

Chong an Mon Oil and Gas