Pasinei nekuti mapaipi esimbi asingatsvi, mapaipi esimbi asingatsvi akaiswa munzvimbo dzegungwa anowanzobatwa nengura dzakasiyana-siyana panguva yaanotarisirwa kushanda. Ngura iyi inogona kukonzera kusvibiswa kwemhepo, kurasikirwa nezvigadzirwa uye njodzi dzinogona kuitika. Varidzi vemapuratifomu ekunze kwenyika nevanoshandisa mapuratifomu vanogona kuderedza njodzi yekuora nekusarudza zvinhu zvepombi zvakasimba kubva pakutanga kuti varambe vachidzivirira ngura zviri nani. Mushure meizvozvo, vanofanirwa kuramba vakangwarira pavanenge vachiongorora mitsetse yemakemikari, mitsetse ye hydraulic ne impulse, uye kugadzira zvishandiso nemidziyo kuti vave nechokwadi chekuti ngura haityisidzi kuvimbika kwepombi dzakaiswa kana kukanganisa kuchengetedzeka.
Kuora kwenzvimbo kunogona kuwanikwa pamapuratifomu akawanda, ngarava, ngarava uye mapaipi ari kunze kwenyika. Kuora uku kunogona kunge kuri muchimiro chekuora kwegomba kana kucheka, izvo zvinogona kukanganisa madziro epombi uye kukonzera kuti mvura ibude.
Njodzi yekuora inowedzera sezvo tembiricha yekushanda kwechinhu ichi ichikwira. Kupisa kunogona kukurumidzisa kuora kwefirimu rekudzivirira rekunze repassive oxide rechubhu, nokudaro zvichikonzera kudonha kwegomba.
Zvinosuwisa kuti ngura iri munzvimbo ine makomba uye ngura yakaoma kuona, zvichiita kuti zviome kuona, kufanotaura, uye kugadzira mhando idzi dzengura. Zvichienderana nenjodzi idzi, varidzi vepuratifomu, vashandisi nevakasarudzwa vanofanira kungwarira pakusarudza zvinhu zvepaipi zvakanakisa zvekushandisa. Kusarudzwa kwezvinhu ndiyo nzira yavo yekutanga yekudzivirira ngura, saka kuzviita nemazvo kwakakosha zvikuru. Nerombo rakanaka, vanogona kushandisa chiyero chiri nyore asi chinoshanda kwazvo chekudzivirira ngura munzvimbo ine makomba, Pitting Resistance Equivalent Number (PREN). Kana simbi yakakwira, PREN ndiyo inonyanya kuramba ngura munzvimbo ine makomba.
Chinyorwa chino chichatarisa maitirwo ekuona ngura iri mumakomba uye ngura dziri mumakomba uye maitirwo ekugadzirisa machubhu ekushandisa mafuta negasi zviri kunze kwegungwa zvichienderana nePREN yechinhu chacho.
Kuora kwenzvimbo kunoitika munzvimbo diki zvichienzaniswa nekuora kwakajairika, uko kwakafanana pamusoro pesimbi. Kuora kwegomba nepaburi zvinotanga kuumbwa pachubhu yesimbi isingatsvedzeri ye316 apo firimu rekunze resimbi rine chromium-rich passive oxide rinoputika nekusangana nemvura inoparadza, kusanganisira mvura yemunyu. Nzvimbo dzegungwa dzakapfuma mumachloride, pamwe nekupisa kwakanyanya uye kunyange kusvibiswa kwechubhu, zvinowedzera mukana wekuora kwefirimu iyi yepassivation.
Kupwanya gomba Kupwanya gomba kunoitika kana firimu repasi pachikamu chepombi richiputsika, zvichiita makomba madiki kana makomba pamusoro pepombi. Makomba akadaro anogona kukura sezvo mashandiro emagetsi achienderera mberi, zvichikonzera kuti simbi iri musimbi inyunguduke mumvura iri pasi pegomba. Simbi yakanyungudutswa inobva yapararira pamusoro pegomba yoita oxidize kuti igadzire iron oxide kana ngura. Sezvo gomba richidzika, mashandiro emagetsi anokurumidza, ngura inowedzera, izvo zvinogona kutungamira mukuboorwa kwemadziro epombi uye zvichikonzera kubuda kwemvura.
Machubhu anonyanya kukanganiswa nekudonha kwemvura kana pamusoro pawo pakasvibiswa (Mufananidzo 1). Semuenzaniso, tsvina inobva mukukwesha nekukuya inogona kukuvadza pasivation oxide layer yepombi, nokudaro ichigadzira nekukurumidzisa kudonha kwemvura. Izvi zvinoshandawo pakungogadzirisa kusvibiswa kunobva mumapaipi. Pamusoro pezvo, sezvo madonhwe emunyu achipera, makristaro emunyu akanyorova anoumbwa pamapaipi anodzivirira oxide layer uye anogona kutungamira kudonha kwemvura. Kuti udzivise kusvibiswa kwemhando idzi, chengetedza mapaipi ako akachena nekuageza nemvura yakachena nguva dzose.
Mufananidzo 1. Pombi yesimbi isina ngura ye316/316L yakasvibiswa neacid, saline, nezvimwe zvinhu zvinogona kukanganiswa negomba.
ngura yemupako. Kazhinji, ngura yemupako inogona kuonekwa zviri nyore nemushandisi. Zvisinei, ngura yemupako haisi nyore kuona uye inokonzera njodzi huru kune vanoishandisa nevashandi. Izvi zvinowanzoitika pamapaipi ane mipata midiki pakati pezvinhu zvakakomberedza, zvakaita semapaipi akabatwa panzvimbo nema clamps kana mapaipi akabatanidzwa zvakasimba padyo. Kana brine ikapinda mupako, nekufamba kwenguva, solution ye ferric chloride (FeCl3) inoumbwa munzvimbo iyi, izvo zvinokonzera ngura yemupako nekukurumidza (Mufananidzo 2). Sezvo ngura yemupako nenzira yayo ichiwedzera njodzi yengura, ngura yemupako inogona kuitika patembiricha yakaderera kupfuura gomba.
Mufananidzo 2 - Kuora kwemupata kunogona kuitika pakati pepombi nerutsigiro rwepombi (kumusoro) uye kana pombi yakaiswa pedyo nedzimwe nzvimbo (pasi) nekuda kwekuumbwa kwe ferric chloride ine acid yakawanda mumukaha.
Kuora kwemupata kunowanzo tevedzera kudonha kwemupata kutanga pakati pechikamu chepombi nekora yekutsigira pombi. Zvisinei, nekuda kwekuwedzera kwehuwandu hweFe++ mumvura iri mukati mekutyoka, funnel yekutanga inokura kusvika yafukidza kutyoka kwese. Pakupedzisira, kukuvara kwemupata kunogona kutungamira pakuboorwa kwepombi.
Mitswe yakakora ndiyo njodzi huru yekuora. Nokudaro, maclamp emapaipi anokomberedza chikamu chikuru chedenderedzwa repaipi anowanzova nengozi kupfuura maclamp akavhurika, izvo zvinoderedza kusangana kwepombi nechibatiso. Mainjiniya ebasa anogona kubatsira kuderedza mukana wekukuvadzwa kana kukuvara kwengura nekuvhura nguva dzose mafixtures uye kuongorora nzvimbo dzepaipi kuti dzikaora here.
Kuora kwegomba uye kukuvara kwegomba kunogona kudzivirirwa nekusarudza alloy yesimbi yakakodzera kushandiswa kwayo. Vagadziri vezvinhu vanofanirwa kungwarira pakusarudza zvinhu zvepombi zvakakodzera kuderedza njodzi yekuora, zvichienderana nenzvimbo yekushanda, mamiriro ekushanda, nezvimwe zvinhu.
Kuti vabatsire vanosarudza zvinhu kuti vagone kusarudza zvinhu zvakanaka, vanogona kuenzanisa PREN values ​​​​dzesimbi kuti vaone kuti dzinoramba sei ngura munzvimbo iyoyo. PREN inogona kuverengerwa kubva pamakemikari e alloy, kusanganisira chromium (Cr), molybdenum (Mo), uye nitrogen (N), seizvi:
PREN inowedzera kana paine zvinhu zvinodzivirira ngura zve chromium, molybdenum uye nitrogen mu alloy. Chiyero chePREN chakavakirwa pakupisa kwe critical pitting (CPT) - tembiricha yakaderera apo pitting inoitika - kune akasiyana masimbi asina ngura zvichienderana nekuumbwa kwemakemikari. Chaizvoizvo, PREN inoenderana neCPT. Naizvozvo, PREN values ​​​​yakakwira inoratidza kuramba kwakakwira kwe pitting. Kuwedzera kudiki kwePREN kwakaenzana nekuwedzera kudiki kweCPT zvichienzaniswa ne alloy, nepo kuwedzera kukuru kwePREN kuchiratidza kuvandudzika kukuru mukushanda kupfuura CPT yakakwira zvakanyanya.
Tafura 1 inoenzanisa kukosha kwePREN kwemhando dzakasiyana dzesimbi dzinowanzoshandiswa muindasitiri yemafuta negesi iri kunze kwenyika. Inoratidza kuti zvirevo zvinogona sei kuvandudza zvikuru kusimba kwengura nekusarudza pombi yemhando yepamusoro. PREN inowedzera zvishoma kubva pa316 SS kusvika pa317 SS. Super Austenitic 6 Mo SS kana Super Duplex 2507 SS dzakanakira kubudirira kukuru kwekushanda.
Kuwanda kwe nickel (Ni) musimbi isingatsvedzeri kunowedzerawo kuramba ngura. Zvisinei, huwandu hwe nickel musimbi isingatsvedzeri hausi chikamu chePREN equation. Chero zvazvingava, zvinowanzo batsira kusarudza simbi dzisingatsvedzeri dzine huwandu hwakawanda hwe nickel, sezvo chinhu ichi chinobatsira kudzoreredza nzvimbo dzinoratidza zviratidzo zvekuora munzvimbo. Nickel inosimbisa austenite uye inodzivirira kuumbwa kwe martensite pakukombama kana kutonhora ichidhonza 1/8 rigid pipe. Martensite ichikamu chisingadiwi che crystalline musimbi chinoderedza kuramba kwesimbi isingatsvedzeri kurwisa ngura munzvimbo pamwe nekupwanyika kwe chloride-induced stress. Hunhu hwakawanda hwe nickel hweinenge 12% musimbi ye316/316L hunodiwawo pakushandiswa kwe hydrogen gas ine pressure yakakwira. Hunhu hushoma hwe nickel hunodiwa paASTM 316/316L stainless steel i10%.
Kuora kwenzvimbo kunogona kuitika chero kupi zvako mupaipi inoshandiswa munzvimbo dzegungwa. Zvisinei, kudonha kwenzvimbo kunowanzoitika munzvimbo dzakatosvibiswa, nepo ngura yemumapako ichiwanzoitika munzvimbo dzine mipata midiki pakati pepombi nemidziyo yekuisa. Uchishandisa PREN sehwaro, mugadziri anogona kusarudza mhando yepamusoro yepombi kuderedza njodzi yekuora kwenzvimbo.
Zvisinei, yeuka kuti kune zvimwe zvinhu zvinogona kukanganisa njodzi yekuora. Semuenzaniso, tembiricha inokanganisa kuramba kwesimbi isingatsvedzeri kusvika pakudonha. Kune mamiriro ekunze anopisa egungwa, mapaipi esimbi asingatsvedzeri e super austenitic 6 molybdenum kana super duplex 2507 anofanirwa kufungwa zvakanyanya nekuti zvinhu izvi zvinodzivirira zvakanyanya ngura yenzvimbo uye chloride cracking. Kune mamiriro ekunze anotonhorera, paipi ye316/316L inogona kukwana, kunyanya kana paine nhoroondo yekushandiswa kwakabudirira.
Varidzi vemapuratifomu ekunze kwenyika nevanoshandisa mapuratifomu vanogonawo kutora matanho ekuderedza njodzi yekuora mushure mekunge machubhu aiswa. Vanofanira kuchengetedza mapaipi akachena uye achishambidzwa nemvura yakachena nguva dzose kuderedza njodzi yekudonha kwegomba. Vanofanirawo kuva nemainjiniya ekugadzirisa vanovhura maclamp panguva yekuongorora nguva dzose kuti vaone kana paine ngura yakatsemuka.
Nekutevera matanho ari pamusoro apa, varidzi vemapuratifomu nevanoshandisa vanogona kuderedza njodzi yekuora kwemapombi uye kudonha kwakabatana nawo munzvimbo dzegungwa, kuvandudza kuchengetedzeka uye kushanda zvakanaka, uye kuderedza mukana wekurasikirwa kwechigadzirwa kana kuburitswa kwemhepo inobuda.
Brad Bollinger is the Oil and Gas Marketing Manager for Swagelok. He can be contacted at bradley.bollinger@swagelok.com.
Magazini yeThe Journal of Petroleum Technology, iyo inonyanya kukosha yeSociety of Petroleum Engineers, inopa ruzivo rwakasimba nezvekufambira mberi mune tekinoroji yepamusoro, nyaya dzeindasitiri yemafuta negasi, uye nhau nezveSPE nenhengo dzayo.