Hpi nghj KHCN 2000 "Nganh Dau Viet Nam trifdc them theky 21' THIET KE VA sCr DUNG LONG OINH TAM CCTNG KET HOP TAO ROI TRONG DIEU KIEN KHE Hd THAN GIENG HEP XNLD VIETSOVPETRO KS Hoang Quoc Khanh XNLD Vietsovpetro PCS TS Cao Ngoc Lam, KS Cao Phi Long Tru&ng Dal hpc Md - D/a chat, Ha Npi TOM TAT DegOp phan nang cao chat lugng bam tram ximang gieng khoan, viec dinh tam ong chong la mdt nhirng dieu kien phai thuc hien truae tien Tuy nhien cau true cua phan idn cae gieng khoan a xi nghiep lien doanh Viet-Xd deu ed khe hd khdng gian vanh xuyen hep (11,1 (12,7mm) nen viee dinh tam dng chong gap khd khan dang ke Nham muc dich dinh tam dng chdng va tao rdi cue bd ddng chay, dae biet viing bd de nang cao hieu qua thay the dung dich khoan bang vCra tram, cac tae gia da de xuat phuang phap thiet ke va lua chgn cac kich thuge hgp ly cua long dinh tam cirng va Idng dinh tam cirng ket hgp tao rdi va thiet lap md hinh lap dinh tam tren cot ong chong Bai bao cung gidi thieu cac ket qua bude dau irng dung cdng cac loai dinh tam cirng thuc te xay dung gieng khoan dxi nghiep lien doanh Viet-Xd OAT VAN £ VSP, CO den 97% sd gieng khai thae la gieng khoan (GK) djnh hudng, dd khoang 10 GK cd gdc nghieng 70-85° nhu d GK 815-8, 428-BK2 v.v Oe nang cao chit lugng bam tram thi dinh tam dng chdng la dieu kien phai thyc hien trudc tien, bdi vi Idng djnh tam (LOT) la phuang tien nhat de giu cdt d'ng chdng nam giua Id khoan Thieu djnh tam, cot dng chdng se tya vao gieng, chit Idng khdng gian vanh xuyen (KGVX) cd xu huong ehi chay phan cd sire can thiiy lye thap, nai ed khe hd rdng Phan cdn lai ludn tdn tai la vung khdng chay, hay cdn ggi la "viing bd" [1] Chinh eae vung bd va cac viing thay the dang ludi se tao cac kenh d i n thuan Igi cho va luu chit xam nhap vao KGVX va di len be mat din den hien tugng xuat hien ap suit giQa cae cot d'ng chdng Nham triet tieu vung bd va tao dieu kien thay the dung dich khoan bang vC/a tram d KGVX thi ta phai thyc hien tdt viec djnh tam d'ng chdng Tuy nhien, dieu kien khe hd gii/a cac cot d'ng chdng rat hep (xem Bang 1, danh gia kha nang tha LOT d VSP) nen nhieu GK d VSP khdng dugc djnh tam hoae dinh tam kem Bang Danh gia kha nang tha Idng dinh tam d XNLD Vietsovpetro SoTT Cot ong mm D/kinh choong mm Khe hd KGVX mm (1)245 ^311.1 33.3 LOT tieu chuan (1)245 (1)295.3 25,4 LOT tieu chuan (1)194 (^215.9 11.1 Khdng the dung LOT tieu chuan (1)178 ^215.9 18,95 LDT tieu chuan (1)168 (1)215.9 23,95 LOT tieu chuan (1)140 (})165.1 12.7 Kha nang stJT dung LDT Khong the diing LOT tieu chuan Cac nghien ciru eiia Bulatov A.l [4] cung eho thay; "Neu ong chong khong dugc dinh tam thi du vat 314 Hpi nghi KHCN 2000 "Nganh Dau Viet Nam trifdc them theky 21' lieu tram co tot the nao di chang nira van khong the thay the het dung dich khoan a KGVX, vay chat lugng tram khong the bao dam" Ngoai ra, de nang cao hieu qua thay the dung djch khoan bang vua, rira vd biin, eae edng ty dau tren the gidi rit quan tam den viec sir dung bd tao rdi vdi eae cau true khae Oe giai quyet ddng bg ca hai vin de djnh tam va tao rdi dong chay, cac tae gia da nghien eiru, thiet ke cac loai LDT cirng (RICEN) va LOT cUng ket hgp tao rdi (TURBO) sir dung dieu kien than gieng hep nhu d VSP THIET KE CAU TRDC CUA TURBO VA RICEN Viec sif dung LDT cirng thyc te khdng he xa la vdi eae cdng ty diu tren the gidi Tuy nhien cac thiet ke LOT cho than gieng hep lai khdng duge phd bien rdng rai Cac Catalog ve LOT deu khdng dua cae loai sin pham tuang ty, bdi vi khe hd vanh xuyen 20 mm da coi la hep, cdn hep tdi 11,1 ^ 12,7 mm thi rat han che thyc te xay dyng GK Ta biet rang, lip LOT cirng vao edt d'ng chdng thi dudng kinh ngoai, cUng ciia he ket cau dng chdng - LOT va sire can thiiy lye tram deu tang Ngoai ra, dieu ta quan tam la hieu qua tao rdi ciia nd nhu the nao? De giai quyet cae van de tren thiet ke TURBO va RICEN, eae tac gia thyc hien theo eae bude sau: • Tdng hgp va phan tich tai lieu ve cac san pham tuang ty de dua mdt eau true tam thdi ciia TURBO va RICEN • Kiem tra cau true bang kha nang tha edng dieu kien GK • Tfnh toan eae thdng sd thiiy luc eiia ddng chay d KGVX bam tram cdt d'ng chdng ed lap TURBO va RICEN • Oanh gia hieu qua sir dung TURBO va RICEN dieu kien thyc te GK Do khudn khd ciia bai bao, cac tac gia khdng di sau trinh bay cae vin de ve ddng chay ma ehi' de cap de'n cae thdng sd eau true cua Idng dinh tam lien quan den kha nang tha cdng dieu kien than gieng hep nhu d VSP Cae kich thudc ca ban cua TURBO duge trinh bay Hinh : / Ixmg dinli uiin kci hc^i irio mi OD : Oudng kinh ngoai L: Chieu dai I- llian; (lan \ l.onc ilinli lam cinic Hinh Ciu true ciia TURBO va RICEN B: Be rdng gan n: cp: Gdc xoan h: Than: G;ui ciia LDT Sd gan xoan Chieu cao gan 315 Hpi nghi KHCN 2000 "Nganh Dau Viet Nam trifdc them theky 21' Lan lugt, eae tae gia trinh bay cac bude thyc hien cdng tac thiet ke Phan tich cac ket qua nghien cufu cua cac tac gia a Cac ket qua nghien eiru cua V I Misenko - [7,8, 9, 11] - Hieu qua tao rdi ciia TURBO tdt nhit sd gan n = ^ - Chieu eao h eiia gan va chieu dai L ciia TURBO cang Idn cang tdt - Khi gde xoan cp = 30-35° dat hieu qua tao rdi tdt nhit, tang cp len tdi 45-60° thi sire can thiiy lye tang len rat nhanh, vay cp > 35° khdng phai la giai phap tdi uu Nhu vay, ta thay ring mac du eae gia trj h va L ciia TURBO cang l(Jn cang tdt tU quan diem tao rdi, nhung thyc te chiing deu bi gidi han, bdi vi chung cdn lien quan de'n bai toan kha nang tha edng edt d'ng chdng ket hgp vdi TURBO Do vay ta can xac dinh duge eae gia tri hgp ly h va L eiia TURBO theo dieu kien sau: LLOT = 0.3 - 0.5 m va D,^,,„g • 00LDTciing ' - 10 mm Nhu vay, chieu dai eiia LOT cirng (LLBT) x i p xi chieu dai ciia dinh tam LQT bd khoan eu Chieu dai va dudng kinh ngoai eiia djnh tam (OT) cd vai trd rit quan trgng viec tao quy dao va dudng kinh than gieng dn djnh de tha d'ng chdng Do vay can phai xem xet md'i quan he giu'a cirng eiia edt d'ng chdng cd lap TURBO (RTURBO) va eirng ciia bd khoan cu BKC (RBKC) diing de khoan doa trudc tha dng chdng Do hieu sd D,hoong • ODLDT - ^ 10mm, nen ap dung phuang phap "tdi da" va "tdi thieu" [2] trudng hgp khd khan nhat (bai toan eye tieu) va de dang nhit (bai toan eye dai) de tha edng edt d'ng chdng dieu kien khe hd than gieng hep nhu d VSP duge danh gia va trinh bay Bang Bang 2: Danh gia kha nang tha TURBO khe hd hep Bai toan Khe hd vanh xuyen Chieu dai TURBO Cue tieu (khd khan nhat) mm 0.5 m Cue dai (de dang nhat) 10 mm 0.3 m Nhu vay, trudng hgp "eye tieu" ta v i n ed kha nang tha edng dng chdng + TURBO vdi cac kich thudc L = 0,5 m, OD = (0/kinh chdong - mm) Trudng hgp "eye dai" khdng ed irng dung thyc te dudng kinh ngoai ciia TURBO xap xi dudng kinh d'ng chdng b Cac san pham cua Turbo Milam, Weatherford, Davis Lynch Hang MILAM cd san pham vdi L=114mm; OD=210mm, Weatherford khdng cd TURBO cho than gie'ng (1)215.9mm nhung cd TURBO eho than gieng 250,8mm tire la khe hd giua TURBO va chodng la 6.3mm Sd gan khae tir 5-6 e Cau triic cua dinh tam (DT-Stabillzer) bo khoan cij (BKC): Hien dang sur dung d XNLD Vietsovpetro Idng djnh tam cd kich thU(Je nhu sau: ODBT= D,f,oong - (3 ^4mm), L^T = 1,5m, dd chieu dai phin gan xoan = 0,5-0,7m Nhan xet Tdng hgp cac ket qua nghien cyu da trinh bay cho thay rang: 316 Hpi nghj KHCN 2000 "Nganh Dau Viet Nam trifdc them theky 21' Xet bai toan hieu qua tao rdi va sire can thiiy lye, ta chgn dugc cac thdng sd cau true tam thai ciia TURBO la (t)=35°; 00= D,^„„„g - 5mm; b = 30mm; LJURBO = 0.5m Sd gan xoan n thay ddi tiiy thuoc dugng kinh d'ng va chieu dai cua TURBO Khi xet them bai toan kha nang tha cdng cdt d'ng chdng cd lip TURBO thi ta phai thie't lap md hinh lip TURBO vao cdt d'ng va so sanh cung eiia he lien ket dd vdi cirng ciia BKC dugc diing de khoan doa trudc tha d'ng chdng THIET LAP MO HJNH LAP TURBO VA RICEN VAO C O T ONG CHONG Oieu kien Oieu kien tha cdng edt d'ng chdng, cho tdi g i n day [3] v i n dugc xac djnh theo dieu kien sau : dhd — dmax Trong dd: dt,d - dudng kinh hieu dung ciia GK d dang phire tap cd nhieu doan Idi Idm, d,^a, - dudng kinh eye dai ciia cdt d'ng cd trang bj cae phan cdng nghe df,d duge tinh theo bieu thirc sau : d,, = 0.5(D, + d J D„ d,„ tuang irng la dudng kinh ciia chodng va can nang Tuy nhien, BKC hien nay, ngoai can nang edn lap them 1-4 OT Oudng kfnh ciia DT ~ duang kinh chdong, khoang each lap eae OT tren BKC gin lam cu'ng tang dang ke, vay khai niem dudng kinh hieu dung khdng edn phii hgp Ve mat hinh hgc, mdt doan d'ng chi cd the di qua Id cd dudng kinh nao dd neu: "dudng kinh cue dai cua ong nho han dudng kinh nho nhat cua id ma no di qua" Oudng kinh GK thyc te rat phire tap bdi eae doan tang-giam gdc, che khoan cac dieu kien dja chit khae nhau, nen bien dang thyc te se cd nhung doan Idi Idm va cac doan cong tang cudng BKC tao Mdi BKC ed eirng RBKC rieng biet, ehinh gia trj eirng quyet dinh gdc lech tang cudng eye dai Do vay cin phai tinh den RgKc (Je khoan doa trucJc tha d'ng Tuy nhien viee tfnh RBKC vdi cac yeu td cdng nghe ed dudng kinh, chieu dai va khoang each bd tri tren cae bd cin khae la edng viee phirc tap, ket qua khd chinh xac Thuan tien va dan gian han la sir dung phuang phap tinh cirng quy uac de ddng thdi tinh toan RBKC va cirng ciia edt d'ng chdng cd lip TURBO va RICEN d tren chung Nhu vay, dieu kien de tha cdng cdt d'ng chdng cd lap TURBO va RICEN than gieng da duge khoan doa la: °BKC ^ RQC+TURBO va DgKc > Doc+TURBO \') Tinh toan cuTng quy u'dc cua cot dng Do cirng R' phin dudi ciia BKC dugc tinh theo bieu thUe :R' = UJC, Trong dd: Mu - md men ud'n phin dudi eiia cdt cin cd chieu dai 40 m; i; : gdc xoay md men M„ tao d phan d i u miit eiia cdt can Nhu da biet, chieu dai ciia mdt phin nao dd eiia BKC cang \d\), dat cang g i n chdong thi 317 Hpi nghj KHCN 2000 "Nganh Dau Viet Nam trifdc them theky 21' cung BKC cang Idn Thdng thudng chieu dai ciia BKC la 60-100m Tuy nhien, chieu dai hieu qua de tao gdc lech tang cudng eye dai la 40m, vugt qua chieu dai thi gde xoay C vin hiu nhu khdng ddi [5] Og cirng C (dai lugng khdng thir nguyen) ciia BKC bat ky dugc tfnh nhu sau : C " m, h n (2) —Z day, L„ L^-chieu dai eiia phan thir iva thu k (k = i+1, i+2 n); m, = E.J (g,)^'^; EJ,, g, - tuang img la eirng ud'n va trgng lugng theo dem vj chieu dai ciia phin thir i; A, - hieu sd giua dudng kinh eiia GK va dudng kinh ngoai ciia phin duge xem xet; n - sd lugng cac phan BKC; Od eirng quy udc R dugc tinh theo edng thirc: R = 0.92 + 1.99.10-'C (3) Cac dai lugng m„ A„ L, ciia cac phin ciia BKC (can nang, djnh tam) va ciia cac loai d'ng chdng dang sir dung d VSP dugc dua Bang Bang Yeu td cong nghe mi OC 0245mm 26,1 Muphta0245mm 26.6 OCcD194mm 22,4 Muphta0194mm 22,8 OCcD178mm 20,9 Muphta0178mm 20,6 OC(D140mm 17,8 MuphtaO140mm 18,2 Li 196mm 190mm 184mm 171mm Dudng kinh ngoai 270mm 216mm 196mm 159mm Yeu td cong nghe mi Cin nang- (l)203mm 20,3 Ojnh tam - (D293mm 25,5 Cin nang - (I)165mm 17,8 Ojnh tam-(D214mm 21,0 Can nang-(t)120mm 14,5 Ojnh tam-0163*mm 17,72* TURBO-210 20,46 TURBO-160 17,54 Ghi ehu: Vdi cac phan ma gia tn m khong co bang tren thi m=8,21+58,33.Dk; a day Dk la dudng kinh ngoai cua dinh tam Bd tri TURBO tren cot dng tha dng chdng vao GK Vdi LOT mem, dudng ki'nh GK chuan thi ta ed the dat LDT/1 dng chdng neu nhu ciu thyc te ddi hdi Oan cir nhu d GK 435 BH, doan 1726-1927m vdi tdng chieu dai 201m, Hang Schlumberger da sir dung tai 32 LOT mem Tuy nhien, dieu kien than gieng hep khdng the lam nhu vay, mdt sd nguyen nhan sau : • Viec bd tri day dac cac TURBO lam tang sire can thiiy luc cue bd din tdi nguy ea pha va via qua trinh tram Sir dung nhieu TURBO cung tao nguy ea xdi vd biin, bde vd bun theo mang din den bit kenh chay tang ap suit pha va via • Do dac diem ket ciu eirng nen RICEN va TURBO ludn giu dn djnh dd lech tam ciia d'ng chdng ma 318 Hpi nghi KHCN 2000 "Nganh Dau Viet Nam tru'dc them theky 21' khdng phu thudc vao tai trgng eua cdt d'ng tac ddng len chiing • Cae nghien cuu cua Misenko V.i [11] cho thiy chieu dai tao rdi eye dai la 4-6m che chay d KGVX la rdi Oe tao vanh da ximang each ly cd hieu qua, can phai ed ft nhat 30m ximang lien ket tdt d doan chan de dng chdng Tu cac ea sd nay, cac tac gia de nghi lip TURBO doan 40 ^ 80m tfnh tu chan de d'ng chdng trd len va doan 200m d phin than trin tfnh tU chan de ciia cdt d'ng chdng da dugc tha trudc dd Nhu vay, de tha cdng edt d'ng theo phuang an tren, ta can phai tinh toan RQC+TURBO sau dd chgn BKC cd gia trj R va dudng kinh thda man cae dieu kien d bieu thuc hay nguge lai: xac djnh gia trj RBKC ciia BKC eho truac, sau dd lya chgn khoang each dat TURBO cho RBKC > RTURBO+OC4 Tinh toan R,OC+TURBO va RBKC dung de khoan doa tru'dc tha dng chdng Od cirng quy udc eiia edt d'ng ehdng+ TURBO cung duge tinh theo cdng thirc (2) va (3) Gia sir LjyRBo"0.5m, tren mdi d'ng chdng lip 01TURBO thi R,OC+TURBO 1,952 > RRKP ^BKC =1,934 (xem eae bang 4a,b d cudi: BKC 215,9mm thudng dugc VSP sir dung de khoan doa trudc tha dng chdng) Nhu vay, vdi LjyRBo=0,5m thi bieu thirc khdng thda man Trudng hgp nay, hoae phai giam LJURBO t^e thda man dieu kien ciia bieu thirc 1, hoae phai lip them DT nhim tang cirng cua BKC khoan doa Cac tac gia chgn giai phap giam LJURBO bdi vi viee tang sd OT lam RgKc tang len, tire la ddi hdi c i n khoan, thiet bj ddng lye khoan v.v , lam viee dieu kien khd khan han Dieu khd thyc hien d VSP cin khoan v.v , sir dung da lau nen mure an toan khdng cao Mdi quan he giua LJURBO va RQC+TURBO cua cac cdt d'ng (|)194 va (l)140mm vdi cac chieu dai khae CLia TURBO dugc trinh bay Bang d dudi TU eae sd lieu d Bang 5, ta xay dyng dd thi (Hinh 2) bieu dien mdi quan he giua LJURBO va RoctiuRBoNhu vay, giu nguyen cac thdng sd eiia BKC thi gia trj RBKC ludn khdng ddi Viee tang chieu dai ciia TURBO lam gia tri RQC+TURBO 'isn tue tang va R tang den mdt mirc nao dd se cat giao vdi dudng thing bieu didn R ciia BKC Ke tUdiem giao nay, bleu thire dieu kien khdng cdn thda man ^ i ^ 1.95 1.9 o 1.85 1.8 1.75 0.1 0.2 0.3 R2 Hinh Mdi quan he gii/a LTU RBO 0.4 R3 0.5 0.6 — ^R4 v a KoC+TURBO' Dieu dd cd nghla la chieu dai eua TURBO khong dugc vugt qua gia tri tai diem giao neu xet theo tinh toan ve eirng Tren ca sd ciia phuang phap nay, cac tae gia da thiet ke TURBO va RICEN vdi cae thdng sd duge trinh bay Bang 319 Hpi nghi KHCN 2000 "Nganh Dau Viet Nam tru'dc them theky 21' I o >> CO CD 3 o- o- CSI crj CSJ CD i o