lot so van de ve sU dung xi mang bcfm tram trong gia co va ket thuc cac gieng khoan dau khf PGS TS Tran Dinh Kien, TS Pham Quang Hieu TrUdng dgi hgc Mo DIa chdt TS Nguyen Hau Chinh, KS Nguyen Hai Som[.]
lot so van de ve sU dung xi mang bcfm tram gia co va ket thuc cac gieng khoan dau khf PGS.TS Tran Dinh Kien, TS Pham Quang Hieu TrUdng dgi hgc Mo-DIa chdt TS Nguyen Hau Chinh, KS Nguyen Hai Som Xi nghiep lien doanh Vietsovpetro Gici thieu TCfthi/c tiin hogt dpng ban 20 ndm, I.IVIddau Khoan gieng la tao sU lien thong cua via dau (boae khQ vdi mat ehung toi trinh bay mpt so van He ve sit dat Muon khai thac dupe dau can phai xay dung dudng dan ben dung xi mang gia co va ket thuc vufng noi via san pham v6i be mat va tbiet bj ebUa dupe dat each cac gieng khoan dau nhtt: dgc diem khong xa mieng gieng De thuan loi va an toan viec van chuyen cua vCta tram, phgm vi dp dung cua cdc dau va gieng khoan tii via len mat dat, cac via dat da phai tiiu chudn, cdc quy lugt tdc dpng den sU dupe each ly va gieng phai dupe gia eo vCfng ehae Chi do, hinh vanh dd xi mang Ngoai ra, gieng mdi eo du dieu kien de khai thae lau dai Chung toi neu nhCTng tUu, bai hpc kinh nghiem cua Xi nghiep Lien doanh Vietsovpetro linh vi/c va ban luan ve chdt litc/ng bam trdm gieng khoan Khi gia eo gieng khoan, sU dung eae ong thep, dupe noi vdi bang ren mpt ept ong dai va tha vao gieng da khoan tdi dp sau tbiet ke Cot ong thep dupe gpi la ept ong chong Than gieng khoan da chong ong se luon luon giUdUoc dang hinh tron suot qua trinh khoan tiep theo va qua trinh khai thae dau sau De CO djnh cot ong chong va each ly eae via, bcrm vOa xi mang vao ept ong ebong, day dung djch khoan ong khoang khong vanh xuyen, thay the ehung tai day, dang len den chieu sau can tbiet va sau dong ran da Qua trinh van ehuyen (bom) vUa xi mang vao khoang vanh xuyen dupe gpi la qua trinh tram xi mang gieng khoan 32 DAU KHi - s o 4/20 PETROVIETNAM Tram xi mang gieng khoan la m d t cdng doan phUe mat va b a m day chiing xudng gieng khoan N h u vay vUa tap va quan t r p n g xay d u n g gieng Neu cdng doan xi mang can d dang the Idng, dp linh ddng ciia vUa t r d khdng dupe thUe hien cdng cd the dan den mat t h d n g sd quan trpng hang dau phai kiem soat Neu trang eae ket qua khoan trUde dd, hoac mat toan bd t h d n g sd khdng t o t (dp linh ddng kem) thi may b a m gieng Cdn neu chat lUpng tram xi mang khdng dat yeu se bj tac va sU ed xay Dp linh ddng cdn duqc gpi cau cd the dan den xuat hien - ap suat giUa cac edt la kha nang b a m ciia vUa Anh hUdng nhieu den dp linh dng chdng, phun tran dau khi, chay nd va gay nhUng ddng la ty le nudc/xi mang (N/XM) Tuy vay, dp linh ddng hau qua khdn ludng Day cung cd the la nguyen nhan lam cung cd the dupc dieu chinh bang hoa chat Cac t h d n g sd sai lech cac ket qua tinh toan trU lUpng dau khi, dan den lien quan de'n dp linh ddng la dp nhdt, dp chay toa va dp sU ehuyen djch lUu chat giUa cac via vdi ehung quanh Nhieu chuyen gia t h u d n g diing khai niem dp cd chenh ap Cac thao tac sUa chUa cho viec tram xi mang quanh (hoac thdi gian quanh) de dac trUng cho kha nang hdng hoac kem chat lUpng deu rat t d n kem, cd the lam b a m va tinh chat linh ddng ciia vUa mac dii ehiing vSn cd mat di tinh nguyen trang cua via ma khdng the khdi phuc nhUng diem rieng biet dupc, cd the lam giam nang lupng, san lupng khai thac Do do, can phai dat dupe d p kin t h i i y lUc giUa ept ong 2.2 Trpng lUpng rieng chong vdi vanh xi mang va giUa vanh xi mang vdi Cot vUa xi mang d the Idng se tao len tac dpng ap gieng, ddng thdi ngan ngUa sU hinh kenh dan suat thuy tmh va thiiy ddng len va day gieng, d d vanh da xi mang tU kbi tram xi mang lan dau trpng lupng rieng eiia vUa cung phai dUpc kiem soat chat Han nufa, each ly t o t cac via ma gieng khoan qua cdn la ehe de tranh hien tUpng thUa hoac thieu ap suat tac dung bien phap bao ve mdi t r u d n g dUdi dat len cae via ma gieng khoan xuyen qua Neu ap suat Sir d u n g xi mang de tram cac gieng khoan dau va la edng nghe da cd tU lau, da cd nhieu edng trinh khoa hpc nghien eUu ve linh vUc nay, cung n h u da cd cac bd tieu chuan quoc gia va qude te ve xi mang tram gieng duqc thUa nhan va ap d u n g rdng rai Mae dii vay, viec sU dung xi mang van cdn nhUng van de can phai chii y quan tam, dae biet dUng tren quan diem t d n g the ve xay dung gieng khoan de khai thac phat trien m d lau dai mdt each an toan va bieu qua qua Idn se gay vd via, vUa xi mang ed the bj that thoat vao Idng dat qua trinh bam tram NgUpe lai, neu qua nhd thi ap suat via Idn han se day cac lUu chat (cac san pham) via vao gieng khoan, gay cac sU cd mat an toan n h u phun tran dau khi, chay no Khi tram xi mang gieng khoan, trpng lUpng rieng ciia vUa cdn la t h d n g sd nhat de kiem soat qua trinh trpn vUa va chat lupng vUa dupe pha che tai thUe dja, phu thude chii yeu vao ti le nUdc/xi mang Trpng lupng rieng ciing bj anh hUdng bdi cac phu gia, vat lieu va cae hoa chat Dac diem cua vufa dung de bdm tram gieng khoan 2.3 Tinh chdt ddng rdn eua viJta trdm Tram xi mang gieng khoan la qua trinh pha che vUa, chil ye'u tU xi mang, nUdc va eae hoa chat, roi b o m vUa dd qua ept dng chong ben ngoai dang len khdng gian vanh xuyen giUa ept dng chdng va gieng khoan Ke't qua ciia b a m tram gieng khoan la tao vanh da xi mang dae cUng va kin xung quang ept dng chdng Cung n h u vUa xay dUng, vUa tram gieng khoan sau b a m vao gieng khoan ket thue qua trinh tram can phai nhanh chdng ddng ran da xi mang Kha nang ddng ran ciia vUa tram giup cd djnh chae chan edt dng chdng de sUdung gieng khoan lau dai dpe theo than gieng Oe cd the thUe hien dUpc viee N h u vay, tinh chat dac trUng ciia hai trang thai Idng thi vUa tram phai cd dac diem gidng va khae so vdi vUa va ran ciia vUa xi mang dupe sU d u n g triet de va can phai diing xay d u n g chil ddng dieu khien 2.1 Dp linh dpng Pham vi ap dung tieu chuan ve xi mang gieng khoan Do gieng khoan nam sau Idng dat nen phai sU dung may b a m de hiit vUa tram duqc dieu che tren be Hien cd 02 bd tieu chuan dUpe phd bien rpng rai DAU K H i - S O 4/2011 33 THAM DO - KHAI THAC D A U KHI nhat la ciia Vien Dau Hoa Ky (API) va tieu chuan mua (khaeh hang) rang san pham thda man cae Qude gia Lien Xd trUde day, la CHLB Nga (fOCT) yeu cau tdi thieu can thie't Ngoai ra, nd cimg dan gian hda moi quan he giUa nha san xua't, nha phan ThUe te tram gieng khoan, xi mang phai thay the dung djch khoan khoang vanh xuyen giUa dng chdng va than gieng tran hoac giua cac edt dng phoi va ngUdi tieu thu Mac dii cae tinh chat tieu chuan la dae trUng cho xi mang vdi mue dich chdng Xi mang can nam doc theo gieng khoan tU be mat de'n dp sau day gieng (hang nghin met), cd nhiet dp tU rat thap dUdi O^C d cac viing ddng bang quanh bat bupc, xi mang gieng khoan can phai cd them nhUng tinh chat khae nUa de dam bao cac nhiem vu chUe nang dUdi gieng khoan ) nam de'n hang tram dp oc Nhiet dp phu thudc Cd the tha'y rang, cac tieu chuan ve xi mang vao gradient dja nhiet d tUng nai Ap suat dpe theo gieng khoan ehi diing de chuan hda thj trUdng than gieng cung thay ddi theo gradient ap suat via, cung cap - san xua't xi mang Viec sif dung (dieu che dja tang, cd gia trj tU va cd the dat den hang tram, vUa tU cac loai xi mang dii tieu chuan) de tram gieng can phai dUa vao dieu kien thUe te ve dja chat, ky hang nghin atmotphe (at) Tieu chuan API cung nhu tieu chuan fOCT khdng bao ham het cac tinh chat ciia xi mang khoang nhiet dp, ap suat rpng nhU vay Cac tieu chuan chi the hien phuang phap thUe dung phan thuat, edng nghe, tai chinh va thdi quen ciia moi cdng ty, qude gia Hau het cac loai vUa bam tram deu phai dUpe dieu chinh cae thdng sd rat khac va thudng khac xa so vdi tieu chuan (Bang va 2) loai xi mang pooclan de sUdung gieng khoan Tieu chuan API (API Specification lOA Twenty- bdi mdt sd tinh chat dupe yeu cau [3] Tieu chuan third Edition, April 2002 ANSI/API lOA/ISQ 10426-1- cung cap eho cac nha san xua't danh saeh cac tinh 2001) va tieu chuan TQCT 1581-96 ed quy djnh pha chat can cd cho san pham va cam vdi ke't ngudi che eae loai xi mang (Bang 1) Bang Quy dinh ve pha vda xi mdng theo tieu chudn API vd TOCT rocT API Thong so Class A, B, Class C, Class D, E, F,H, Class G PCG Ty le nUdc/xi mang 0,46 0,56 0,38 0,44 0,50 Ty vuTa tUOng lifng 1,88 1,78 1,98 1,90 1,83 Bang Thi du ve thdng so ty trgng thi/c te pha vQa tram gieng khoan Cong ty N9 gieng khoan H°-^ Sehlumberger (loai xi mang: G, dat tieu chuan API) W2 Ne3 NO BJ (loai xi mang: G, dat tieu chuan API) N9 N9 Vietsovpetro 34 DAU KHi - s o 4/2011 Ne7 So lUorng vQa xi mang, m^ Ty le, % Trong lUOng rieng vuTa, Theo tieu Khac tieu g/cm' chuan chuan 6,7 93,3 10,1 89,9 12,6 87,4 7,2 92,8 14,2 85,8 12,2 87,8 100 44,0 1,54 3,2 1,90 59,1 1,49 6,3 1,90 104,0 1,54 15,0 1,90 181,0 1,54 14 1,90 126,0 1,49 21,0 1,90 79,2 1,50 11,1 1,90 80,0 1,52 18,0 1,57 PETROVIETNAM So lieu Bang cho thay xi mang pha nhU tieu nhUng trudng hop cu the, ket luan t h d n g nhat dupe chuan (API) thUc te chi chiem khoang dUdi 15%, riit la: ap suat thuy tinh ciia cot vUa xi mang giam di phan nhieu la pha xi mang khdng n h u tieu chuan NhU dang ke qua trinh ehuyen pha Cac nha cdng nghe vay, cac yeu cau va tinh chat ciia vUa xi mang quy djnh rat can biet gia trj ap suat bi giam de kiem soat ap suat via tieu chuan khdng the la yeu cau cho vUa se b a m vao gieng khoan Nay sinh van de la xi mang phai dii tieu chuan, cdn vUa xi mang thUe te b a m tram gieng khoan lai khdng n h u tieu chuan hoac khdng quy chuan dupc, ma phu thude vao dieu kien thuc te ciia m d va gieng khoan ThUe te qua trinh thiiy hoa de chuyen pha Idng sang ran (vao giai doan trung gian ma vUa xi mang khdng hoan toan la pha Idng cimg chua dat tdi dp cUng de la pha ran), hien tUpng thay ddi ap suat va truyen ap suat thuy tinh ciia edt vUa xay rat phUe tap [6] Cac ket qua Cac yeu to anh hiTofng den sd hinh vanh da xi ap suat phdng thi nghiem ddi vdi vUa xi mang mang gieng khoan dieu kien m d phdng gieng khoan deu nhan thay ap suat giam rat manh va sau xi mang ddng ran, dat tdi ThUc te cho thay ed rat nhieu ye'u t d tac dpng den viee hinh vanh da xi mang ciia gieng khoan, bao gia trj chan khdng [4] gdm cac yeu t d ky thuat, dja chat, cdng nghe Trong do, Hien nay, quan diem dupc chap nhan rdng rai han cd ca cac yeu t d chii quan hay khaeh quan Trong bai bao ca la ap suat thuy t i n h ciia edt vUa xi mang giam de'n ap cac tac gia chi trinh bay m p t sd yeu t d tac ddng n h u suat thuy tinh eiia edt nudc d i i n g de pha xi mang Dieu nhUng quy luat thupc ve ban chat ciia vat lieu xi mang duqc giai t h i c h : vUa chuyen trang thai (xi mang can lam sang t d thuy hoa) se lam tang sU lien ket giUa cac hat xi mang, tang dp ben gel (gel strength) de tU d d t r p n g lUpng ciia 4.1 Sd chuyen pha vd hien ti/png gidm dp sudt thiiy tinh cua cot vCta Dae diem ca ban va cung la van de chii yeu ciia viee diing xi mang b a m tram la t i n h chat d d n g ran ciia vQa tram, the hien d viee vUa can d trang thai Idng t r o n g m p t khoang t h d i gian nhat djnh va phai chuyen t h a n h pha ran sau thUe hien xong cdng doan b a m tram Khi vUa xi mang d dang Idng eung n h u da xi mang d ehiing, nhUng giUa cac hat van cdn cac Id rdng t h d n g (mao dan) chUa day nUde, d d edt nUde eae 16 rdng se la ap suat ma cot thuy tinh ciia vUa xi mang dat tdi qua trinh chuyen pha Hien tupng giam ap suat thiiy tinh qua trinh ehuyen pha ciia vUa xi mang la doi tUpng dupe nghien eUu cdng nghe tram gieng khoan Tren Hinh la so bieu dien hien tUpng va hau qua eua nd dang ran, da cd nhieu p h u a n g phap t h i nghiem va da dupe nghien cUu tUOng ddi hoan chinh de xac djnh cac tinh chat dae trUng ciia chiing d dieu kien binh t h u d n g (nhiet dp va ap suat quyen), nhU cac cdng trinh xay dUng thudng tha'y, sU chuyen pha khdng gay nhUng van de nghiem trpng Do dd, eae tai lieu ve xi VOa xi mang a trana thai long Vi>a xi mang s< ngirng ket Ap suat thuy ttnh cua cot Mua truy§n den via mang xay dung cimg hiem de cap de'n dieu Tuy nhien, vUa xi mang dupe b a m xudng gieng khoan (nhu da trinh bay d phan tren) tao edt ap suat thuy tinh de can bang ap suat via thi sU chuyen pha lam thay ddi ept ap suat thuy tinh can phai dae biet ehii y Cae tai lieu ve edng nghe tram xi mang va cac cdng trinh nghien eUu cho tha'y, ve mat ly luan van ehua giai thich dupe day dii quy luat thay doi ap Thin gian Hinh Si/gidm dp suat va hien tugng ddng xdm nhap theo mUc chuyen trgng thdi cua vda xi mdng ti/ldng sang ran suat Tren cd sd thue nghiem va thUe tien DAU KHi - s o 4/2011 35 THAM DO - KHAI THAC DAU KHi Liic dau (trang thai A) toan b d ap suat ciia ept vUa xi m a n g t r u y e n de'n via tao phan ap ngan can d d n g di vao gieng khoan t r a n g thai B, vUa bat dau phat trien dp quanh thi ap suat t r u y e n len via giam d i Khi vUa bat dau ngUng ke't (trang thai C) thi ap suat giam rat nhanh de'n gia trj ap suat via va liic d d n g tU via di vao vanh xi m a n g (trang thai D) Sau ngUng ke't, xi m a n g da la dang chat ran (trang thai E), cd dp eUng Ve nguyen tac, d d n g k h d n g the di qua dupe va bj dUng lai d t h d i nhat la sUthay doi kich thUdc ciia vat (giam di) so vdi luc dau Vdi xi m a n g tram gieng thi liic vUa cdn la Idng, nd se cd dang va kich thUde ciia vat (khdng gian) chUa nd N h u vay de gia ed chae va kin vanh xuyen gieng khoan, thi yeu cau trUde tien la sau d d n g ran kich t h u d c xi mang k h d n g co ngdt, vl neu co ngdt se cd khe h d va khdng gian vanh xuyen se k h d n g kin Cac tai lieu va thuc te t r o n g p h d n g t h i n g h i e m ciia XNLD cho tha'y cac loai xi mang tieu chuan va t h o n g d u n g vdi dieu kien d d n g ran t r o n g mdi trUdng kin va each ly thi deu CO ngdt, gia trj co ngdt d o duac la 1,70 -1,88 % sau 48 d i e m gid N h u vay xi m a n g binh t h u d n g nhU tieu chuan la N h u vay, tram xi m a n g qua via k h i t h i sU ehuyen t r a n g thai eiia vUa xi m a n g keo t h e o hien t u p n g g i a m ap suat t h u y t i n h t r u y e n len via D d n g khdng phu h p p cho mue dich b a m tram gia co gieng khoan Trong [1 ] edn neu y tUdng thay xi mang bang cac loai khac p h i i h p p b a n di vao vanh xi m a n g va ehi dUng lai sau xi m a n g da ngUng ket Quang dUdng d d n g di dupe Co rut (contraction) khac vdi co ngdt la hien tuang t r o n g vanh xi m a n g phu t h u p c vao tdc d p di ehuyen giam t d n g the tich tuyet ddi ciia he vat chat cac (sU chenh lech ap suat, kieh t h u d e kenh d a n , loai qua trinh vat ly, boa hpc [2], [5] Thiiy hoa xi mang la khi) va k h o a n g t h d i gian ciia giai doan chuyen pha phan Ung ciia xi mang vdi nUde, co riit xay tong Neu khoang t h d i gian ehuyen trang thai dii Idn t h i the tich cac san pham cudi cung tao nhd han d d n g ed the dat tdi m i e n g gieng k h o a n tong the tieh cae chat ban dau t h a m gia phan Ung Sau Thuc te tren the gidi va d Xi nghiep Lien doanh Vietsapetro (XNLD) da cd nhUng trUdng hpp xua't hien phun sau qua trinh bam tram gieng khoan, chUng t d ed tac ddng ciia quy luat giam ap suat chuyen pha eiia vUa xi mang Tuy vay, can phai nhan thUe rang, phan Idn cac trudng hop khae khdng nhan thay hien tupng vi ddng di ehuyen vanh xuyen ehUa dat tdi be mat xi mang ngUng ke't chan lai ngUng ke't, hien tUpng eo riit xay khdng tac ddng nhieu de'n co ngdt kieh thUdc ben ngoai ciia mau da xi mang, co rut chi lam tang t o n g the tich (kich thUdc va sd lupng) cae 16 rdng ben ciia cau true da xi mang Theo tai lieu [2] va t h i nghiem xi mang ciia XNLD, sUco riit dupe trinh bay Bang Cd the tha'y rd rang, d o ap suat t h i i y tinh qua trinh chuyen pha ciia edt vUa xi mang 4.2 Hien tiipng co ngot vd eo rut qud trinh thiiy hod xi mdng p h d n g t h i nghiem thi chinh hien tUpng co riit va co ngdt da lam eho ket qua ap suat d o dupe giam nhanh va giam x u d n g dUdi ap suat mdi trUdng, tUc ehan Co ngdt (shrinkage) dupe hieu mdt each khai quat khdng n h u nhan xet t r o n g [4] Bang SiJgidm (%) the tich tuyet doi (co rijt) cija xi mang Sau Sau Sau 28 Sau 100 Ghi chil 2,8 4,8 6,0 6,9 Theo [2] Xi mang Pooclan thieu phu gia thach cao 2,7 8,0 8,6 8,7 Theo [2] Xi mang o w e 1,7 Xi mang Pooclan XimangOWCL DAUKHi - SO 4/2011 2,2 5,2 4,2 5,5 Phdng TN XNLD Phdng TN XNLD Phu luc Sd lieu co rut thiJy hda nhdng pha co ban cua clinker [5] Khoi li/ong rieng, kg/m^ So TT Phdn ijrng thuy hoa CaO+H,0=Ca(OH|, 3Ca,SiO,+3H,0= Ca(OH),+2CaO, SiO,x2H,0 2CaO, SiO,+2HjO=2CaO, Si0„ 2H,0 3CaO,AI,0,+ Ca(OH),+ l H,0=4CaOxAI,,0„ 19H,0 4CaO,AI,O,+Fe,O,+2Ca(OH),+ 10H,O= 3CaO,AI,0,x6H,0+3CaO,Fe,0, x6H,0 Dung dich rSn:C,A(F)H, 3CaO,AI,0,+6H,0=3 CaO,AI,0,, 6H,0 4Ca0,AI,,O,+Fe,O,+ 19H,,0=4CaO,Ai,0,xFe,0,, 19 H,,0 3Ca0,AI,O,+CaSO4,2H,0+16H,O=3Ca0,AI;O,,CaS0,„2 H,0,18H,0 4CaO,AI,0,,Fe,0,+2CaSO.,2H,0+2 Ca(OH),,+30H,O=3CaO,AI,O,,CaSO„18H,,O+3CaO,AI,O„ CaS0„18H,0 Dung dicin rSn: "AFm" [Hia) to 6Ca(OH),+6SiO,,(cat thacli anli)=6CaO,6SiO,, H,0 (xonotlite) + 5H,0 11 5[CaO,SiOJ+l 3SiO,(cat thach anhl+ 15H,,0=315CaO,6SiO,,5H,0) (Tobemoritel 12 5IP-2CaO,SiO,|+7SiO,(cat thach anh)+10H,O=2|5CaO,5SiO;,5HjO] (Tobemoritel 13 2[3CaO,SiO,l+4SiO,(cat thach anhH H,0=6CaO,6SiO,,H,,0 (xonotlite) 14 3IP-2CaO,SiO,)+3SiO,(cat thach anhl+ H,0= 6CaO,6SiO,.,H,0 (xonotlite) 15 16 3CaO,SiO,+2SiO,(diatomitel+3H.O=3[CaO,SiO,,H;01(hydros ilicateC-S-H(l)| 31y-2CaO,Si0 1+3SiO,,(cat thach anh)+H,0=6CaO,6SiO,,H,0 (xonotlite) Chat dau Chatdau Gia tri Cong thOc Gia tri Cong thtfc Gia tri CaO 3320 Ca(OH), 2230 CaO 3,01 H,0 1000 H,0 10 Ca(OH), Chat cuoi Chat dau Chat cuoi Cong thi:fc Co rut Khoi luong tuong umg The tich rieng, m^/kg.l 0^ Chat cuoi 4,48 Tuong doi Tren dv Congthitc Gia tri Cong thOc Gia tri CaO 56 Ca(OH), 74 4,85 3,02 H,0 18 6,00 3,30 mVkg,10' C)S 3200 Ca(OH)j 2230 C,S 3,13 Ca(OH), 4,48 c,s 228 C-S-H (II) 208 H,0 1000 C-S-H (II) 2460 H;0 10 C-S-H (II) 4,07 3H,0 54 Ca(OH)j 74 P-CjS 3280 C-S-H (II) 2460 p-c,s 3,05 C-S-H (II) 4,07 C-S-H (II) 208 2,36 1,19 H,0 1000 H,0 10 C,A 3040 CAH, 668 17,17 22,28 Ca{OH), 2230 C,AHi 1810 C,A 3,29 Ca(OH), 4,48 C,AH, 5,52 C:S 172 2H,0 36 CA 270 Ca(OH), 74 HO 1000 H.O 10 18H,0 324 C,AF 3770 C,AH, 2520 C,AF 2,65 CjAH 3,97 CAF 486 C,AH 378 Ca(OHI, 2230 C,FH„ 2800 Ca(OH), 4,48 C,FH„ 3,57 2Ca{0H), 148 CFH, 436 18,53 10,97 H,0 1000 H.O 10 10H,O 480 C,A 3040 CAH 378 23,68 17,34 H,0 1000 C.AF 3770 C,,AFH, 828 20,28 20,15 H,0 1000 C,ACsH|, 730 10,38 12,86 14,008 12,8 -5,79 -2,41 2,50 1,2 0,39 018 -5,32 -1,92 -9,6 -3,16 5,6 2,28 -5.0 -1,5 C,A 3040 Cs,H, H,0 2310 1000 C,,AF 3770 Cs,H, Ca(OHl, CAH CAFH,, 2220 CA 3,29 H.O 10 CAF 2,65 H.O 10 C,AH, C,AFH„ 3,97 4,50 C.A 270 6H,0 108 CAF 486 19H,0 342 C,A 3,29 Cs,H, H.O 10 4,33 CAF 2,65 2310 2230 Cs,H, Ca(OH), 4,33 4,48 H.O 1000 H.O 10 30H,O 540 Ca(OHl, 2230 C.S„H 2700 Ca(OH), 4,48 C„S„H 3,70 6Ca(0H), 444 C.S„H 714 SiO, 2650 H,0 1000 SiO, 3,77 H,0 10 6Si0, 360 2H,0 90 CsSsH, 2440 CsS.H, 5,0 CS.H, 2190 2C,S„H5 1460 C,A 3200 SiO, H.O 2650 1000 |3-C,S 3280 SiO, H.O 2650 C,S 3200 SiO, H.O 2650 1000 P-c,s 3280 SiO, H.O 2650 1000 c,s 3200 SiO HO T - C,.S 2970 SiO, HO 2550 1000 C,ACsH„ 2520 "AFm" (H„) CS.Hs 1850 2020 2440 1000 CS.H 2700 CjA 3,13 SiO, H,0 3,77 p-c,s 3,05 SiO H.O 3,77 c,s 3,13 SiO, H,0 3,77 10 3,05 3,77 c.s 3,13 2400 SiO, 3,77 1000 H,0 10 y- C.S 3,37 SiO, H,0 3,77 10 C-S-H (1) CS,H 2430 2700 4,95 C,S.H, 5,0 10 SlO: HO 2700 •AFm" (H„) 5,41 10 P-cs C.S.H C,ACsH„ CjS.H C,S.H 3,70 3,70 10 C-S-H (11 C.SjH 4,12 3,70 CA 270 Cs,H, 16H,0 172 288 CAF 486 2Cs,H, 2Ca(0H), 344 148 SC,A 1140 13SiO, 15H,0 780 5C,S 860 7510, 10H,O 420 180 2CS 456 4SiO, H,0 240 18 2"AFm" (H„) 1528 270 3CS 516 3510, H,0 180 CS.H C.S.H 714 714 18 C,S 228 2Si0, 3H,0 120 54 3C,S 516 3Si0, H,0 180 18 3C-S-H(I) C.S.H 402 714 THAM DO - KHAI THAC DAU KHI Ve chat lUcrng borm tram gieng khoan Cd cac phuang phap sau day de danh gia chat luang tram xi mang gieng khoan: - Do vj tri dang len eiia xi mang gieng khoan nhd tinh chat toa nhiet - Do mat dp xi mang ben ngoai dng chdng - Do sU gan ke't ciia xi mang vdi ept dng chdng (bang sdng am thanh) (da khai thac het dau), dd dieu khien va kiem soat cac ye'u td quyet djnh ke't qua phi vat chat trdthanh nhiem vu rat phUctap va khd nhan thUc - Ep thU dp kin ciia vanh xi mang ben ngoai edt dng chdng Cd the tha'y rang phuang phap dau chi xac nhan ve mat vat chat ed sU hien dien ciia xi mang Phuang phap ep thU ed ve dac trUng cha viec danh gia mue dich cua tram xi mang, vay thUe hien phuang phap lai rat khd dieu kien gieng khoan Phuang phap su gan ke't thudng chi thUe hien tai mdt thdi diem ma vanh xi mang lai phai lam viec lau dai Hau het, cae ehuyen gia deu chUa thda man vdi cac phuang phap tren day Chiing van chUa dac trUng dupe vai trd nhiem vu ciia vanh xi mang ddi vdi viec khai thac dau Bai hoc va kinh nghiem cua XNLD 6.1 Thdnh ti/u Cdng tac gia eo gieng khoan (chdng ong va bam tram xi mang) chie'm khoang 15 - 20% gia gieng khoan, ed y nghTa quan trpng quyet djnh chat lUpng gieng khoan nhU mpt cdng trinh xay dung ngam Idng dat Do do, tram xi mang gia cd gieng khoan d XNLD ludn dupe coi (nhan thUc) la mpt nhUng cdng doan phUe tap chu trinh xay dUng gieng khoan va dupe quan tam dae biet De'n nay, XNLD da khoan dupe han 300 gieng de phue vu cho cdng tac Nhu da trinh bay tren day, lam kin khdng gian tham dd va khai thae dau tai cae mo tren them vanh xuyen gieng khoan (each ly cac via vdi luc dja Viet Nam DUa vao dac diem dia tang gieng va vdi be mat) trUde mat cung nhU lau dai la mue khoan di qua va kinh nghiem tich luy duqc, xi tieu quan trpng nhat eiia bam tram xi mang Vanh nghiep da thUe hien va tUng bUde hoan thien da xi mang la "ke't qua vat chat" eiia bam tram xi edng tac bam tram gia cd gieng khoan, dap Ung mang Chat lupng ciia cdng viec bam tram xi dupe yeu cau dat mang ehi la dam bao hoan cac thao tac theo ke hoaeh de pha trpn va dUa dupc vUa xi mang tdi cac vj tri da du tinh d gieng khoan khdng xay sU cd (tao dUpe vanh da xi mang) Cdn chat lupng va mue tieu eiia bam tram gieng khoan (gia cd gieng khoan) lai la ky vpng ma vanh da xi mang tao se mang lai Cd the ndi day la "ket qua phi vat chat" phu thudc vao rat nhieu cac cdng doan va yeu td khac (dja chat, ky thuat, thiet ke vUa, vat lieu, cdng nghe tram ) va chiing dupe coi la ddi tupng nghien cUu ciia cdng nghe bam tram xi mang gieng khoan [2] Odi tupng chinh ciia cac gieng khoan la khai thac dau tang Miocen ha, Oligocen va mdng phang hda Do dd cau triie gieng khoan ciing ed nhUng dac diem tuang Ung Cau triic dien hinh trinh bay d Phu luc Can cU vao bieu ap suat via va vd via tha'y rd rang vUa xi mang pha theo tieu chuan API tU loai "G" hoac theo tieu chuan GOST tU laai "PCG" la khdng phii hpp V~i nhU vay se xay hien tUpng vd via Dua vao dac diem dja chat ky thuat dac trUng nhu vay, XNLD da xay dung tieu chuan xi nghiep ve xi mang de sd dung Cac loai xi mang duqc dimg deu la xi mang bie'n Trong thUe te, ket qua phi vat chat ndi tren chi tinh o w e , OWC-S, OWCL, OWCL-S dupe san xua't ed the danh gia dupc trpn ven sudt qua trinh nudc Thdng sd chii yeu dupe trinh bay khai thac va sau gieng da hoan nhiem vu Phu lue 38 DAU KHi - SO 4/2011 PETROVIETNAM Phu luc Dgc diem dia tdng, dp sudt via va cdu trdc gieng khoan cua XNLD Tuoi iJat da 06 sau Bia tSng Gradient ap suat 08 1,0 12 1,4 1,6 1,1 SH J Ddi vdi quy luat giam ap suat Ti dung dich Cau true gieng khoan L t h i i y t i n h , XNLD chii t r p n g ap dung cac bien phap ngan ngUa bang cac giai phap cdng nghe 720mm NB Pvv=1,3Ptt khae nhU: lap dan pha vUa vdi cac thdi gian quanh va ngUng 700 SHI ke't khac nhau, ap dung loai vUa 508mm cd tinh each ly cao d cac doan quan trpng ciia gieng, dieu khien Pv=Ptt 1,10±0,02 P w =1 1,5 Ptt giam chieu dai doan tram, tao phan ap, nghien cUu he xi mang SH2 1400 khoang t h d i gian chuyen tiep, 339,7 mm ngam Cd the ndi rang, cdng tac b o m tram eiia Xi nghiep da 1,12 ±0,02 chil ddng kiem soat dupe quy luat giam ap suat thiiy tinh (tren Hinh 2200 1, trang thai F minh hpa cho viec SH3 ap dung cd ket qua cac bien phap ngan ngUa sU xam nhap Pv = 1,06 Ptt 1,16±0,02 giai doan chuyen pha) Cd hai trudng hop xay sU cd phun SH5 sau qua trinh bam tram d SH7 3100 XNLD deu cac cdng ty djch vtj 244,5 mm va cac nha thau ben ngoai ve b o m Pv=1,59-1,61 Ptt tram thuc hien P w = H ,89 Ptt 3800 SH11 4000 AF 68 ±0 02 6.2 Van dexdm nhap Tuy khdng xay cac sU cd 193,7 ni,m nghiem trpng ve phun qua Pv=0,8-0,9 Ptt Pv'^=1,5-1,60Ptt 139 t7 mm 1,06 ±0,02 d XNLD van edn chUa thUe sU Than tran 0165,1 Ghi chu: Pv-gradient dp suat via; Pvv - gradient dp sudt va via, Ptt - gradient ap sudt thuy vanh xi mang, van de xam nhap kiem soat dupe Cd nguyen tac tinh xam nhap vao vanh xuyen xi Phu luc Cdc thdng sd cua vi/a xi mdng trdm gieng khoan cua XNLD mang la: Khi ndi len xi mang edn la dang Idng; Giam ap suat Cacthong so C6t 6ngch6ng Loai viira xi mang Thetich, m' Ty trong, g/cm' Thcri gian quanh, phut Thdi gian chdxi mang, gid dng cich nt/dc 30" (720 mm) VUa xi mang (OWC) 30 1,72 120 24 Conductor 20" (508 VCta xi mang OWCL 117 1,52 250 36 Ong trung gian 13 3/8" (340 mm) 36 VOa xi mang OWCL 209 1,52 390 Ong khai thac 5/8" (245 mm) vera xi mang OWCL 90 1,52 260 36 ViJa xi mang OW/CL- 29 1,57 150 36 0nglLrng7 5/8"{194mm) Vaa xi mang aWC-S 18 1,72 OngliJngS 1/2'(140 mm) VCta xi mang OVi/CL- 10 1,52 150 36 thiiy tinh, co riit va co ngdt xi mang chuyen trang thai, va Hinh eae khe nUt, vi khe nUt tren mat tiep xuc ciia xi mang vdi dng chdng, xi mang vdi dat da gieng khoan va khdi xi mang sau da eUng hoat ddng ciia gieng gay NhUng han ehe t r o n g cdng tac ngan ngUa su xam nhap giai DAU KHi - s o 4/2011 39 THAM DO - KHAI THAC D A U KHI doan xay dung gieng khoan ciia XNLD la : - Khdng ap dung (hoac ap dung khdng triet de) cac chil dao ciia tram xi mang gieng khoan Phdng chdng xam nhap tU tram xi mang lan bien phap cdng nghe de tang eUdng he so thay the dung dau van la van de cap bach hien eiia Nganh Dau djch khoan bang vUa xi mang qua trinh bam tram va XNLD - Khdng kiem soat hien tUpng co riit va eo ngdt eiia Tai lieu tham khao vUa tram chuyen trang thai va sau ddng ran Les Skiner, 2007 Drilling - ChUa de cap den kha nang bien dang ciia da xi advance World Oil, | September2007, p 21 mang dieu kien gieng khoan dang khai thac dau hoac bam ep via E.B.Nelson & D.Guillot, 2007 Well Cementing, Second edition, 773p, p.37 6.3 Quan diem ve nghien cdu vdt lieu trdm gieng Tinh chat each ly ciia vanh da xi mang la ddi hdi quan trpng nhat ddi vdi bat ky vat lieu va phuang phap sU dung Do dd nghien cUu vat lieu tram can nham tdi mue dich Cac nhiem vu can giai quyet la: - Nghien cUu dieu kien, cac che dp lam viec ciia gieng khoan d cac giai doan khac - Nghien cUu va de xuat cac tieu chuan (eae thdng sd mdi, can thie't) dac trung tinh each ly ciia vat lieu tram ndi Worldwide cementing praeriees, first edition, API, 1991,465 p, p 14 (DaiiBMeB fl.T., Arafl>KaHOB O.M., AcawioB X.3., 1987 Pe3ynbmambi uccnedoeanua CHUMeHua 2udpocmamuHeCKoeo daeneHUfi cmon6a marvinoHa?KHoeo pacmeopa Bypenne He(t)TflHbix M rasoBbix eKBa>KMH B ocTio>KHeHHbix yc;ioBHflx VBdeKucTaHa Tpyflbi urMPHI/irM, TaiuKeHT, CTp 59-63 Bbin 63 Nguyen HUu Chinh va nnk, 1996 Hieu iing co rut ehung va ciia vat lieu tram dieu kien gieng khoan qud trinh thtjy hda xi mdng Bao cao Hpi nghj Khoa Tach rieng va tich hop khai niem ve tinh chat (yeu cau) hpc lan thU 12 trudng DH Md - Dja chat 10/1996, Quyen 6: trudc mat vdi tinh chat lau dai cho vat lieu tram - vUa Daukhitr.229-235 tram - Phuong phap xac djnh cac thdng sd da de xuat - Nghien cUu tinh chat each ly ciia cac vat lieu tram dang sUdung - Nghien cUu che tao cac loai vat lieu mdi theo mue dich dat Ket luan Xi mang gieng khoan phai thda man cae tieu chuan, nhUng phan Idn dieu che vUa de sU dung tram gieng can phai xuat phat tU dieu kien thuc te khac tieu chuan Giai doan ehuyen trang thai ciia xi mang tram gieng la giai doan nguy hiem hien tUpng giam ap suat thiiy tinh Hien tupng co ngdt va co riit ciia xi mang gay hai cho mue dich 40 DAU KHi - SO 4/2011 Nguyen HUu Chinh, 1997 Hien tuqng giam dp sudt qud trinh thuy hda xi mang Jap chi Dau khi, 1/1997 tr.39-46 ... borm tram gieng khoan Cd cac phuang phap sau day de danh gia chat luang tram xi mang gieng khoan: - Do vj tri dang len eiia xi mang gieng khoan nhd tinh chat toa nhiet - Do mat dp xi mang ben ngoai... XNLD 6.1 Thdnh ti/u Cdng tac gia eo gieng khoan (chdng ong va bam tram xi mang) chie''m khoang 15 - 20% gia gieng khoan, ed y nghTa quan trpng quyet djnh chat lUpng gieng khoan nhU mpt cdng trinh... la dang Idng; Giam ap suat Cacthong so C6t 6ngch6ng Loai viira xi mang Thetich, m'' Ty trong, g/cm'' Thcri gian quanh, phut Thdi gian chdxi mang, gid dng cich nt/dc 30" (720 mm) VUa xi mang (OWC)