]]f^l^n^diig hrgng Ky thudl cdng trinh Van lai vd Cdng nghe Bien DUY TRi TiNH TRANG KI THUAT TOT CHO QUY GIENG LAM VIEC DE HOAN THANH TOT NHIEM Vy CHIEN LUOC KHAI THAC D A U KHI VUOT KE HOACH H A N G NAM Le Nhat Tuan, Vu Qudc Tuyin, Pham Ba Hicn Lien doanh Vict Nga Vietsovpetro 105 Le Lgi phudng TP Vung Tdu linh Ba Rja - Vung Tdu Email: tuyenvq rd@vietsov.com.vn Tdm tat: Trdi qua 30 nam xdy dirng vd phdt Irien, Lien doanh Viesovpeiro dd Ira thdnh luc luang chii lire cita nganh ddu Viet Nam Vietsovpetro dd cd Irong lay quy giing khong Id gdn 400 giing phdn bd Iren cdc md dang khai ihdc, cdc cdu lao trien vgng mai lim Ihdy thugc cdc Id thim luc dia phia Nam Viet Nam cd sdu muc nude bien tir 50-I50m Vietsovpetro dd khai Ihdc an lodn gdn 200 Irieu Idn ddu Ihu gom vd dua ve bd hdng ty m^ khdi Cd duac thdnh luu ndy nhd VSP dp dung nhieu gidi phdp cd gidi phdp "Duy tri tinh trang ki thuat tot cho quy gieng tdm viec" ddng gdp mdt vai trd rdl quan Irgng Cdc gidi phdp ndy dugc the hien dudi ddy TO MAINTAIN GOOD TECHNICAL CONDITION OF OIL FIELDS IN ORDER TO FULFILL THE STRATEGIC TASK OF OIL EXPLOITATION Abstract: Passing 30'^ years of building and development, the J V Vietsovpetro has become main force of Vietnam petroleum Vietsovpetro has enormous oil f elds abgut 400 wells gver the exploiting area and the areas wilh promising oil resources with the depth from 50 to I SOm Vietsovpetro has safely exploited near 200 million crude old and billion cubic meters of gas In order lo have the achievements, Vietsovpetro has applied many solutions among Ihem "maintenance good technical conditions of oil fields " is the imporlanl one Here below, the authors present in detail Ihe solution I Thiit ke toi un thiet bi long giing Nhirng nam dau cua thdi ky khai thac md Bach Ho dng khai thac dugc thiit ke dgn gian gdm cgt dng ep hgi cd dudng kinh khac dugc kit ndi theo mat cat hinh thang dudng kinh dng tang ddn lit dudi Ien Kiiu dng nang ehi phu hgp vdi dieu kien khai thdc ap sudt via Idn - che dp khai thae ty phun Nhung gpi ddng san pham va sau thcri gian lam viee cdu true the hien cd nhiiu bdt Igi Hot nghi Khoa hoc vd Cong nghe Bien lodn cjudc Idn Ihd V Tren eg sd tinh tgdn eae dac tinh dja chdt ky thuat ciia ddi tugng khai thdc, luu lugng, ap sudt nhiet dd va cau true dng chdng khai thac cita gieng Phdng Khai thae Vien NIPl dii dua thiit ki Id hgp Ihiel bj Idng gieng nham ddm bao an lodn va nang cao hieu sudt lam viec cua gieng khai thae dau eung nhu giing bgm ep tri dp suat via Hinh md ta cau Iriic bd BCO chudn dang dugc sir dung d XNLD Vietsovpetro Vice sir dung thiit bj Idng giing loai trir dugc kha nang rd ri nen qua di NKT gay nguy hiim ddi vdi giing gaslift luu lugng thdp, lam che dng khai thac bj biin dang Khi ddn^ van an loan ndng cd thi tiin hanh sua chita khu vyc dau gieng Khi ddng van an loan sau cd thi tiin hanh sua chira, thay the eac phdn tit thiit bj long giing nhu ddng md van tuan hoan, thay van gaslift Su dung thiit bi Idng giing d cdc giing cd nhicl Hinhl dd cao cho phep diiu hda sire cang cua cgt dng khai thdc, nhd cd ong diiu hda nhiet Nhd cd nipel (cac mil chan) tha cac nut vao dd ta cd the thu dugc dp kin cua loan bd dng khai thae Vdi Id hgp thiit bi Idng giingnay dam bdo tdt dieu kien di tiin hanh eac cdng viec nghien cim va khdo sat giing va di ggi ddng cho gieng mdi khoan xong hoac chuyin gieng tir khai thac tu phun sang kliai thac bang gaslifl hoac cd he thing gaslift cd thi ditng nd thau rira viing can ddy cho cac gieng bom ep vdi muc dich 1dm saeh viing ddy trudc dua vag bgm ep Vjec sii dung td hgp thiet bi Idng giing d cac giing bom ep giup cho dng chdng khai thac beri viJng trudc dp lyc thuy tTnh va dp lye thuy ddng hgc Nhd cd paker nen khoang vanh xuyin giita dng chdng khai Ihac va edt dng nang dugc lap day chat Idng tro Ngan ngira nhu'ng anh huong tieu cue ctia cac phuo'ng phap gia tang san luong len tinh trang ky thuat giing Di tang ddng ddu d cac giing khai thdc, XNLD Vietsgvpetrg da ap dung nhieu giai phap dd hieu qua nhat va chi dao nhat la giiti phdp tac ddng viing ddy gieng (xit ly via) vdi phuong phap xir ly via bang axit va vg via bang thuy luc Xir Iy via bdng axit Xir ly via bang axit la bom ep mdt khdi lugng hdn hgp axit vag via sdn pham Dudi tac ddng ciia hon hgp axit, cae kenh, khe nirt, hang hoc cua via dugc md rgng Nhd vay, dp tham cua via dugc tang Ien rd ret, tao dieu kien tdt ehg ddng san pham tir via di vag day gieng Nhung phuong phap cd anh hudng khdng tdt den tinh trang ky thuat gieng axit tae ddng vdi thiet bj De giam thieu kha nang an mdn kim loai cita hdn hgp axit nggiti diing chat ire che an mdn kim loai chung ta da sir dung sg dd chuan cita eau true thiet bi Idng gieng (Hinh 1) Vien NIPl de xuat Nhd ed cau true trudc bgm ep axit vag gietig, thiit bi Idng gieng dupe ep thir dp kin Nhd viiy da kiem soat duge dp kin ciia toan bd dng nang,-ngan-ngira duge su that thoat axit tir NKT bom ep vdi ap suat eao Ngoai mdt khuyen nghi dugc dua ra: Trgng dieu kien cho phep, phuong an tdt nhat de dam bag thiet bi Idng gieng lam viec lau ben phdng Khai thac ddu Vien NIPl Tien bim Ncing luang Ky ihugl cong irinh Van tai va Cdng nghe Bien khuyen nghj nen sir dung ihiat bi 6ng mam (coiltubing) da xu ly axil viing can day gicng Cong nghc cho phep bao vc dugc cac phan ttr ciia thiat bi long giang (6ng khai thac, van sau, nipel, v.v ) tranh dugc su huy hoai bai'tTxit Ngoai he thflng 6ng mdm co tha tac dgng mgt each co lua chgn vao viing can tac dong voi chinh xac cao, dc dang tao bon axit, dac biet rat hicu qua doi voi khoang via dugc mo ion, nhanh chong dua giang \-ao khai thac Vd via bdng thuy luc Jrong giai doan tir nam 1994 dan nam 2010.0 mo Bach H6 da ti^n hanh xii' ly vung day giang bang nirt via thuy lucva xu iy via bing axil duoi ap suat cao vol s6 lugng la 133 Ian/97 gi^ng Trong 68 Ian/53 gi^ng dugc lian hanh boi hang Schlumberger lai hang Halliburton thuc hien He s6 cong cac giing tdng Oligocen la 64% ddi voi cac gieng tang mong he so cong la 67% Trong cac nam d5u thuong xay cac sir CO sau: - Ket packer (da xay o gi6ng); - Dong luan hoan chat long nut via xuat hien va di chuyan tir viing duoi len viing tren tian hanh nut via thuy luc (trong giing); - Ong chong khai thac bi bien dang mgt so gicng Ngoai ra, dai da so gieng dugc lien hanh niirt via Ihuy luc kel hgp voi xir ly via bSng axit duoi ap suat cao tir truoc nam 1997 dau co su gia tang ap suat ngoai 6ng ch6ng va dong chat luu xuat hien vanh xuyan xi mang ngoai ong chong Nguyen nhan ciia cac hicn lugng Iren la mil via, ong chong khai thac va vanh xuyan xi mang ngoai 6ng ch6ng phai chiu mgt luc nen Ion dan den bian dang tham chi bj vo De tranh nhung su co nhu da phan tich tren can phai giam luc lam bien dang 6ng chong nut via thiiy lire co the xir dung cac giai phap sau: - Xac dinh sue ben thuy luc ciia khoang khong vanh xuyin voi dp ldn la bao nhieu Van de thuc te giai quyet rat kho Nhung co the tang cuong kha nang ciia ong chong khai thac chong lai ap luc tac dgng len no va vanh xuyen xi mang bang tang cuong luc doi ap khoang khong vanh xuyen den dp Ion cho phep bang each day chat long vao khoang khong vanh xuyen; - Xac dinh khoang dat packer ke tir de ong chong khai thac tro nen hay ke tCr vi tri phia tren cua khoang md via bang ban Phong Khai thac Vien NIPl da de xuat: Tinh loan moi lien he sir phu thupc giiia to hgp cac chi s6 dja vat Iy khoang khong vanh xuyen xi mang vdi chenh ap lam vo vanh xuyen xi mang dan den dong chat long tir via nude (co the d phia tren hoac d phia dudi via san pham dang xu ly) di vao khoang via dugc md bing bin Day la ket qua cua cac cong trinh nghian ciru, xir ly va minh giai tai lieu dia vat ly, thiiy dgng luc ciia hon 500 gieng d 32 mo ciia cong hoa Lian bang Nga Moi lien he sir phu thupc vilt dudi dang phuong trinh "sau: [P] = Ko*(168/D)*[(l,4+l,18*X, + 1,09*X2 + 0,71*X3 + Hcii light Khoa Inic vd Cdng nghe Bien lodn quoc ldn lliirj^ 0.014*X4-0,012*X;-0.5*X6)] (2.1) Trong dd: Ko:Khi (Xi + X2 + X3 ) = 3-5m bien ddng Irong khodng 0,6+0,93 Khi (XI + X2 + X3) = 5-1 Om biin dgng khoang 0,93+1,0 Khi (Xi + X2+ X3) ldn hon 10m bicn ddng khoang 1,0-1,1 Xi - khodng than gieng cd chat lugng xi mang tdt theg titi lieu carota sieu iim, m X: - khoang than gieng ed chat lugng xi mang kem, m X3 - khoang than giing cd xi mang xen ke khoang khdng ed xi mang, m Xj - Tdng chieu dai cdc khoang via khdng tham ke ca khoang da thd chdng dng trudc, m X5 - Gdc nghieng cua than gieng, dp Xc - Do lech tam cua dng chdng thay ddi lir den D - Dudng kinh dng chdng cd tram xi mang, mm [P] - Gradient nut via thuy lye di qua khoang dng chdng cd tram xi mang, MPa/m Ap sual (P) Idc dpng len khoang than gieng cd tram xi mang dudi de dng chdng cd the linh loan theo edng thirc sau: P = Pm+10-'*H*(pi.-pLx)-PT (2.2) Trong dd: Pm - Ap sudt mieng gieng vd thiiy lyc, MPa H - Do sau de dng chdng cd trdm xi mang Pl - Ty trgng chat Idng nirt via thuy lyc PLX - Ty trgng chdt Idng ed hda tan xi mang, bdng 1030kg/m^ PT - Tdn hao dp lye NKT nijt via thuy lyc, MPa Khoang each can thiet dat packer ke tir di dng chong khai thac hay tir khoang bdn hay tir giira cac khoang bdn dugc tinh theg cdng thiic sau: Lp=l,05*P/[P] (2.3) Theo ket qua nut via thuy lyc, ap sudt du tac ddng len dng chdng each packer mdt khoang duge tinh theo edng thuc: AP = [P]*LT-IO-=*HTP*P„ (2.4) Trong dd: LT - Khoang cdch thuc tir di dng chdng din vj tri dat packer HTP- Chieu sau thyc cua packer, m ^ ^r^ • ' "V- Tieu ban_mng lugng, Ky thudl cong trinh Van lai va Cong nghi Bien pvx - Ty trpng chdt Idng cd hong khoang khdng vanh xuyen, kg/m' Tren cg sd tai Ii$u vd via thiiy luc da dugc tien hanh d XNLDVietsovpetro vd bdng cac cdng thuc tren (2.1; 2.2;2.3;2.4) xdc djnh dugc chieu sau dat packer va dp lyc du tac ddng lam bien dang ong chdng d viing thye te dat paker Nhd vay ta cd thi dieu chinh cde thdng sd eua qua trinh nut via thuy luc vdi hudng cd lgi cho ben gieng Hoac, di giam dp luc du tac ddng lam biin dang dng chdng bang each tang cudng luc d khoang khdng vanh xuyen tren paker giSa dng khai thac va dng chdng khai didc bdng cdch dd ddy chdt long vao khoang khdng vanh xuyin dd Bdng mdt hai each se tranh dugc hu hdng dng chdng khai thae va thiet bj Idng gieng, bao dam dp ben vimg ciia vanh xuyin xi mang gdp phdn lam tuoi thg cita giing dugc keg dai Sir dung thiit bi ddu gieng phu hpp vdi dieu kien cu the cua mo Vi$c lua chgn va su dung thiet bi khai thac ddu giing phai dap ung duge diiu kien hau biin nhiet ddi khac nghiet nhu nhiet mdi hudng cao 20+40°C, dm ldn (100%) Trong nhung nam qua da sit dung loai thiet bi khai thac ddu giing ed xudt xu tir cdc nude SNG, Nhat, My, Mehico Hien tren md Bach Hd cd 20 giing dang stl dyng cd thiit bi phun mieng giing va dau dng chdng ed xuat xur tir cac nude SNG (kieu OKK va AFK) khdng dap ting dugc cac yeu cau dudi day: Sau mdt thdfi gian lam viee bg thiet hi khdng lam kin mieng giing gua trinh khai thdc, ep via, khao sat gieng; Khdng treo dugc paker mieng gieng nen cac gieng dd khdng the trang bi thiet bj Idng gieng (BCO) dd khdng cd cac Id thoat de ket ndi cac dudng dau thiiy lye diiu khien van ngat sau va dudng hda phSm btmi vao gieng can; Khdng the thay dudng kinh cdn khai thac nham dua gieng ve che dp khai thac tdi uu; Khdng cd kha nang ddng giing va dap giing kip thdi trudng hgp khdn cdp Theo khuyen cao cua nha may san xuat thi chi khai thac 20 nam nhung thye te da gdn 30 nam; Tinh trang thiin va cdc van tren cay thdng bi an mdn nhiiu, mdt sd van Hinh Khdo sdt cdy thong vd ddu giing kieu OKK va AFK da su dung gdn 30 nam khdng cdn giii kin dugc bgm ep thti Di bao dam an toan san xudt, loai trir nguy hiem tiim an thiet bi phun dau giing, dutJi sy chi dao eua Tdng giam dde va hyc tiip la chanh kT su vi$c thay thi thiit bi mi^ng giing kiiu OKK vd AFfTbSng thiit bi hien dai hem (JKS) khdng chi dugc tiin hanh theo mdt Id hinh khoa hgc va thyc hien nghiem ngat cac qui djnh de ma cdn dap ihig yeu cau san xuat Hdi nghi Khoa hgc vd Cdng nghe Biin lodn qudc ldn thir Trong kiam tra xac nhan tinh trang kT thuat diu giing da tiln hanh thuc hien cac budc sau: A- Quan sdt bdng mdt thuang Kiem tra tai lieu goc da dugc cap nhat vl tinh trang cua d4u giing va thiit bi phim mieng gieng (Hch su su dung co dugc d gian va phdng kT thuat san xu4t xi nghiep khai thac); Kiam tra ngoai hien trudng: Tinh trang cua cac vo lang dong md van; Tinh trang ciia cac vdng bit kin, kha nang lam viec va kin cua cac van bang each md va dong vao; Tinh trang cac khe hd cho cac sprisop thupc cac van va ca nhung khe hd cong nghe; Tinh trang ren ciia cac bulong, 6c (muc dp an mdn, set ri ); Tinh trang cua van d§n dpng; Sir phu hgp cua thdi han kilm tra cac ap kl da dat Hinh dpi khao sat dang lam viec vdi thiet bi mipng gieng khai thac da sir dung gan 30 nam Dua vao ket qua kham xet dau ong chong va va thiet bi phun (cay thong) bang m3t thudng da lap ban danh muc cac khuyet tat vdi muc dich sira chua va thay the cac chi tilt hi hong khong dap ung yeu cau kT thuat B- Qui trinh kiem tra bdng thiet bi sieu dm Theo so da dinh, nhirng vi tri nhay cam va cac chi tilt can phai lam sach ri set B5ng may sieu am dd khuylt tat tiln hanh kiem tra cac diem va cac diem khdng dudi 20 diem Nhiing diem d6 dupe phan bo d lihiing vj tri c6 tiem an nguy hiem ldn nhat (vi tri noi, bj tac dpng bdi set ri va bi mon va dap co hpc) Tat ca cac m^t bich dugc kiem tra vdi muc dich khdng de sai sdt la bd quen cac nut le chung Tren CO sd bdo cao cua ngudi dung may v^ phan tich kit qua khuyet tat, Hinh Bau giing OKK AFK duac thay bdng JKS co nhiing kit l u ^ wk khuyin tin cay cao hem ngh| da dugc dua ra; Thyc te vi^c thay thi cac chi tilt dung theo "Qui dinh": nhiing chi tilt cua d4u giing, cay thong c6 muc mon thuc te vl dp day cung nhu dp mdn, dp rpng khe nut dugc phat hien sieu am Ion hon 25% dp day, dp rdng cho phep thi nhit dinh phii dugc thay thi Tnrdng hgp nhd hon 25% thi chi cin tiln hanh tinh toan kilm tra dd ben that ki cang them mgt Ian nua Doi vdi phan dng xi lanh, dp bin c4u tao cua chi tilt dugc tinh tdan trSn phan 6ng xi lanh-theo cdng thiic dudi dSy: ^ Pth« = (200 *Sn *R)/Dn < [Pth,i] [Pthur]- Ap suat cho phep thir nghifm, MPA; Sn - Dp day danh dinh cua chi tilt, mm; •P II lai vd C 'ling nghi Biin 15 K - Sue cang cho phcp MPA: Un - Ducmg kinh ngodi mm - Sau tinh todn kicm nghiem Ihiet bi cdn khd nang lam vice dugc dii lap bicn bdn "Gia han sir dung" dd ciing dua cdc linh loan ben ciia Ihicl bj C- lid sir cua qud Irinh khdo sdl thiel bl ddu dng chdng vd Ihiet bi phun mieng giing (cdy Ihdng) dd lap dugc logi sail- Bicn ban kicm nghiem thiit bj ddu dng chdng \a ihicl bj phun mieng gieng: Ban Ihiet ke dd khuyet lat: Kel luan vi kil qua dd khuyil lai; Sg dd thiet bj mieng gieng; So dd vi tri dd khuyil lat tren cdc ehi tiit thiit bj phun va ddu giing; Bang dien tu ghi qua trinh khao sdt thiit bj phun va ddu giing; Bicn bdn thir dp kin thiit bj phun lir van Irung lam trd len; Bicn ban gia ban sir dung thiit bj phun va ddu giing Nhd cd quy Irinh tren day Lien doanh Viclsovpclro dd thyc hicn lit vice chuyin he ddu gieng lir OKK AFK sang IKS mgl each tdt dcp Xem hinh Mac dii phai khdc phuc sy bat hpp ly bang each che lao adapter phan chuyen licp giii:a ddu dng chdng vdi lhii;t phun mieng gieng khdc chiing lcai(cay Ihdng JKS) ngoiii cdn phdi ddp irng nhicu yeu ciiu kT thuat nghiem ngat khac nira Kit luan Gicng khai thae dau hay gieng bgm ep nude tri dp suat via lit mgt he Ihdng cdc Ihiet bj cd lien quan chat ehc vdi nhau, bd sung hd trg lan la mdt thyc the thdng nhal Vice danh gid tinh trang kT Ihual cde Ihict bj gicng cdc Ihdng sd lam viec cita ehimg, dp suat mieng gicng ddi hdi su phan tich chi tiet khdng chi nham dam bao hdan Ihdnh kc hoach san xual ma cdn dap dng cdc yeu cau kT thual an loan cho ngudi va Ihiel bj bag vc mdi Irudng Nhd vay ma nhiing gieng cd dp sua! cao luu lugng ldn (hang nghin lan dem) diu dugc van hanh an tgan luyct ddi.Trong sudt ba muoi lam nam qua, sd lieu gieng ihay ddi Iheg nam linh trang giiing dugc cap nhat, phan lich va cdc bicn phdp de nang cag hicu qiia cita gieng dugc dua kjp thdi cho tirng truimg hgii cu the Thdi gian qua d cac md cita Vietsgvpetro da liin hanh hon 500 lan sira chira gicng Lie sd khai thac va he sd sudung cua cdc gieng khai thac ddu dat 0,97 vd 0.92 Ddi vdi gieng bom ep nude iri dp sudl via eg cac chi sd lugng ung la 0,92 vd 0.95 Day la nhiing chi sd eao Sd lugng giiing thupc quy giing quan Irdc, dy phdng, sira chira vd huy khdng ldn Tinh Ihdi diem hi?n tai eae md Lien doanh Vietsgvpetrg cd 22 giing quan trac vd 18 gicng dy phdng Dieu dd ehimg minh rdng viee tri quy giing lam viec d cac md Lien doanh Vietsovpetro la rat tdt, gdp phdn quyit djnh vdo viec hoan nhiem vu ehien lugc-hoan thdnh kc hoach khai thac Lo'i cam o'n Tdc gia va ddng tac gia xin cam gn Vien Khga hgc va Cdng nghe Viet Nam, Tap doan ddu qudc gia Viet Nam va Lien doanh ddu Viet Nga Vietsovpelro da thuc hien chu dao Cdng van 3409A'PCP-KGVX 21/5/2010 cua Chinh phu, qua dd da tag eg hdi eho chung tdi nhftngngudi lam ddu tren biin Viet Nam dugc tham gia vdo dien dan xin edm cm Ban td chirc Hdi nghj Khoa hpc Cdng nghe bien loan qudc lan Ihu V, Ban To chuc Tieu ban Nang lugng, kT thuat edng trinh, van tai va edng nghe Bien, Ban lanh dao Lien doanh Viet Nga Vietsovpetro da giup dd chiing tdi hoan tdt Bao cao Khoa lldi ngln Khoa hgc vd Cdng nghi Biin loctn iiiicic hin ihirV hgc iiii> Kinh chiic lai cd cac qui vi ddi ddo sire khoc Ihyc hicn Idl cac Chi Ihi Nghi qu\cl clia Dang \ii Nha mrdc "\o chien luge Bii-n Vicl Nam din nam 2020" gdp phiin bdo ve \ttng chdc chu quyen Bicn Dao Viel Nam TAI LIEU THAM KIIAO Phdng Khai Ihac ddu Vien NCKlIcSiTK ddu bien, Vietsovpetro- Bdo cdo NCKH nam 1994; 1995:1996; 1998; 2001:2002:2003; 2004; 2005; 2006, 2007; 2008; 2009.2010 Clcrenlixl D V "Thuy lyc", Mokva 1984; Ngu>cn Trudng Sgn I'lDC-Telio Viet nam Ilien tugng dp suat gia lang viinh xu>in vd bicn phap phdng ngira Tuyen liip cac cdng Irinh khoa hgc lap 34 Ha Ndi 6/2001 Phung Dinh Thuc Dueng Danh Lam Vietsovpetro Improvement of wellbore zone treaiment icchnolggy Tor the bascmcnl of Bach ho Field, Conference on "The oil and gas induslry on Ihe eve of 2L' eenlury" Tai lieu hudng ddn RD No-52-97VSP Vien dau Tap doan dau qudc gia Viet Nam-Bdg cdg "Cdng nghe lang cudng he sd Ihu hdi dau lir than dau tram lich luc nguyen bang cde td hgp cdc phugng phap hgd ly vi sinh" Vunu tau 10/2010 ... tang cuong kha nang ciia ong chong khai thac chong lai ap luc tac dgng len no va vanh xuyen xi mang bang tang cuong luc doi ap khoang khong vanh xuyen den dp Ion cho phep bang each day chat long... Hinhl dd cao cho phep diiu hda sire cang cua cgt dng khai thdc, nhd cd ong diiu hda nhiet Nhd cd nipel (cac mil chan) tha cac nut vao dd ta cd the thu dugc dp kin cua loan bd dng khai thae Vdi... giing va di ggi ddng cho gieng mdi khoan xong hoac chuyin gieng tir khai thac tu phun sang kliai thac bang gaslifl hoac cd he thing gaslift cd thi ditng nd thau rira viing can ddy cho cac gieng bom