Hoi nghj KHCN 2000 "Nganh Dau khi Viet Nam trifdc them theky 21'''' MOT SO KET QUA NGHIEN COU TRONG VIEC HOAN THIEN, AP DUNG GIAI PHAP KHOAN GIENG CO THAN NGANG, A NGANG TAI XNLD VIETSOVPETRO Nguyen Van[.]
Hoi nghj KHCN 2000 "Nganh Dau Viet Nam trifdc them theky 21' MOT SO KET QUA NGHIEN COU TRONG VIEC H O A N THIEN, AP DUNG GIAI P H A P K H O A N GIENG CO THAN NGANG, A NGANG TAI XNLD VIETSOVPETRO Nguyen Van Ut, Truang Cong Tai Phung Hiru Thuac Vien NCKH&TK XNLD"Vietsovpetro" TOM TAT Mot nhdng giai phap tang cudng khai thac dugc ap dung rong rai cong nghiep khai thac dau la giai phap khoan gieng than ngang, a ngang Trong bai viet tnnh bay mot so ket qua ap dung cong nghe khoan tai XNLD Vietsovpetro va de xuat phuang phap tinh toan hugng khoan toi uu doi vOi da nui ne MdOAU Mpt nhtirng giai phap tang cudng khai thac dugc ap dung rdng rai cdng nghiep khai thac dau la giai phap khoan gieng than ngang, a ngang Giai phap dac biet quan trpng eho cac md khai thac ngoai bien, cung nhu cae via dau ed chieu day chura dau khdng Idn va vdi mdt sd lugng cdng trinh bien han che Ngay nay, cdng nghe dang tren da phat trien va hoan thien, trd mdt nhtrng giai phap quan trpng, giai quyet dugc nhu'ng van de chien luge phat trien md viec hinh he thdng mang ludi gieng khoan khai thac va bam ep nude, dam bao mat dp bao trum ciia gieng va tan khai thac tai nguyen mdt each hgp ly Mot nhurng giai phap tang eudng khai thae quan trpng da va dang ap dung rdng rai d XNLD Vietsovpetro la cdng nghe khoan gieng than ngang va a ngang Trong pham vi bai viet tac gia thdng tin ket qua thu dugc qua mdt vai nam ap dung edng nghe khoan gie'ng ngang, a ngang eho ddi tugng tang mdng md Bach Hd tai LDDK Vietsovpetro, ddng thdi trinh bay mdt sd ket qua nghien ciru viec hoan thien cdng nghe OAC OIEM Hin N^ CAC T H A N H T A O GRANITOID MONG M BACH HO Be mat mdng trudc Kainozoi ciia md Bach Ho theo cau true hinh thai dja mao dugc chia vdm: vdm Bae, vdm Trung tam va vdm Nam Cac tao mdng duge dac trung bdi dae diem thach hpc khdng ddng nhat bao gdm cac da xam nhap ed phan tU diorit, granodiorit tdi granit, granit alaskit Tren ea sd ddi sanh vdi cac phirc he maema xam nhap phan luc dja mien Nam Viet Nam vdi cac da mdng md Bach Hd theo cac dae diem thach hpc, thach dja hda, nguyen td vet, tudi ddng vi phdng xa da cho thay: Oa ed tudi trudc Kainozoi ciia md Bach Hd cd the chia phirc he maema xam nhap: phire he Hdn Khoai, phire he Ojnh Quan va phirc he Ca Na [1] Theo cae tai lieu dia vat ly nghien ciru khe nirt cae Id khoan va cac md ta khe nirt cac mau khoan phire he Ojnh Quan bj nirt ne kha manh me Mat dp khe nirt trung binh khoang 17-18 khe nirt /10m, eao nhat cd the dat den 60 khe nirt /10m (gie'ng 65) Trong cac mau khoan cd doan da bj ea nat rat manh me Qua phan tich cac bieu dd khe nirt Id khoan da ghi nhan tao phat trien manh nhat la nhdm khe nirt phuang Tay Bae - Odng Nam dac biet la theo phuang 145° Thir den la nhdm khe nirt phuang a kinh tuyen va phuang Odng Bae - Tay Nam Nhdm 61 Hoi nghj KHCN 2000 "Nganh Dau Viet Nam trifdc them theky 21' khe nirt phuang a vl tuyen phat trien yeu nhat Nhin chung cae khe nirt thuang ed gdc cam kha thoai va dao dpng khoang kha Idn 10-70° it thay cae khe nirt thang dirng Tuy nhien, cac m i u khoan thi cae khe nirt ed gdc cam tU 70-90° lai chiem ty trpng kha Idn Phan Idn (85%) cac khe nut d day thudc loai khe nirt md ttrng phan hoae khe nirt ddng kin Vi khe nirt md chiem ty trpng it han 10-15% Theo cac tai lieu dia vat ly nghien ciru khe nirt cac Id khoan va cac md ta khe nirt cac mau khoan thi cac tao eiia phirc he Ca Na bj nirt ne kha manh me Mat dp khe nut cac Id khoan khoang 15 khe ntrt /10m, eao nhat d nhung doan bj ca nat mat dp cd the dat 45 khe nirt /10m Qua thdng ke va phan tich eae bieu dd khe nirt Id khoan da ghi nhan dugc he thdng khe nirt nhu sau: -He khe nirt phuang 150° cam 60-70° ve phia Odng Bae, -He khe nirt phuang a vT tuyen cam 60° ve phia Nam 1270 \ -He khe nirt phuang a kinh tuyen cam 65-70° ve phia Odng 90 I -He khe nirt phuang 45° cam 50-60° ve phia Odng Nam / ,/ -He khe nirt phugng 60° cam 60° ve phia Odng Nam -He khe nut phuang 25° cam 70-80° ve phia Odng Nam -He khe nirt phuang 130° cam 50-60° ve phia Odng Bae Hinh Oae trung khe nirt tao Ca Na mdng md Bach Hd Cac tai lieu tren cho thay phat trien manh nhat la nhdm khe nirt phuang Odng Bae - Tay Nam ma chii yeu la phuang 45° thir den la he TB-ON (phuang 150°) va phuang a kinh tuyen (28%) He khe nirt phuang a kinh tuyen phat trien yeu han ca Phan Idn khe nirt deu ed gdc cam trung binh 60-70°, thudc loai ddng kin hoae md mdt phan (42%) va vi khe nirt md (38%) Cac vat chat lap day cac khe nirt phan Idn la cac mach zeolit va calcit mau trang, trang phdt xanh vdi kich thudc mach 3300 m^/ngay) • Theo ket qua minh giai, phan tich tai lieu dja chan 3D mdi nhat d XNLD Vietsovpetro thi cac gieng 467, 456,458,449 dugc khoan vao viing xa cac dirt gay kien tao Tai diem 01.01.1999, san lugng dau tU cac gie'ng than ngang, a ngang chie'm 25,42% tren tdng sd lugng dau khai thac ttr md Bach Hd, dd ty trpng quy gie'ng chi chie'm 13,67% TINH TOAN Ht/ONG KHOAN GIENG TOI lAJ CHO LlAJ Lt/ONG LON Kha nang khai thac dau tU cac via nirt ne tu nhien bang mdt he thdng gieng khoan la gidi han Vi vay, viec xac djnh hudng khoan de thu hdi dugc nhieu dau la- rat quan trpng Tac gia [4] diing phuang phap phan tich tuyen tren mat phang de tim kha nang khoan qua mdt each Idn nhat cac nirt ne, suy rdng de xac djnh ty le ddng chay nurt ne Idn nhat cua gie'ng Sau dd phan tich dugc tdng quat hon cho trudng hgp ba chieu thuc te Cac nirt ne dugc khao sat nhu mpt tap hgp nirt ne - mdt he thdng nirt ne, co ciing hudng phat trien, cd khoang each deu (S*) va mdt dp md dac trung (e) Hudng khoan tdi uu ciia gieng phu thudc vao nhieu yeu td nhu dp md, khoang each, su djnh hudng ciia mdi he thdng nirt ne Trong trudng hgp chi cd mpt he thdng nirt ne dan vudng gdc vdi the nam via (Hinh 2), cd khoang each bieu kien ciia nirt ne (S) mat phang phan Idp Theo djnh ly Pytago: S = S* l + t a n g ' p ] " ' = S * [ l + t a n g ' ( e - k ) ] " (1) Trong dd: S*: khoang each gitta cac nurt ne (the closest fracture spacing) 9: gdc phuong vj CLia S* k: gdc phuang vj ciia S Bae Gocphirang vi o S^S^'^ va P Tap nut ne Tap nirt ne Tap nut ne Hinh 64 Hoi nghj KHCN 2000 "Nganh Dau Viet Nam trifdc them theky 21' Khi dd, k ed the duac xem nhu la gdc phuang vi diing khoan dinh hudng Tan suat ma than gieng khoan chan qua cac nirt ne dugc gpi la "ty le chan nirt ne " (P) va chinh la sd cac nirt ne (n) bi chan tren mpt dan vj chieu dai eiia gieng (L) Ty le chan nirt ne chinh la sd nghich dao cua chieu day bieu kien ciia nirt ne vdi hudng k Ty le chan nirt ne (P) duge xac djnh: L S S*[l + tang'(e-k) (2) ,1''2 Vdi muc dich tim hudng k de cd the chan dugc hau het cae nirt ne sudt chieu dai gieng va tim hudng de ty le chan cac nirt ne la cao nhat Oe dat dugc muc dich nay, P dugc hieu nhu la mdt ham theo k Lay vi phan phuang trinh tren theo k va cho bang ed: dP =0= -^smie-k) dk S* (3) Phuang trinh (2), (P), dat gia tri Idn nhat hay nhd nhat k = 0, k = Phuang trinh (3) bang khdng cd nirt ne via, tire la S* = co, hoae sin(6 - k) = 0, (9 - k) = 0, ±7t, ±2:1 , t m n , tat ca cac gia trj deu tdn tai cung phan tich Oao ham bae hai ciia P theo k la: d-p COS' (e-k) (4) s- 9P/3k = irng vdi gia tri Idn nhat ciia P (phuang trinh 2) = k, dao ham bae hai cua P < Nhu vay, ddi vdi mpt tap nirt ne dan, hudng k, ty le chan nut ne P dat gia trj Idn nhat dat song song vdi hudng (9) cua cac nirt ne Hudng khoan tdi uu la hudng vudng gde vdi mat phang ciia eae mat nirt ne Md rdng tinh toan xem xet den dd md ciia nirt ne dugc cho: FN- S;[l + tang-(e,-k,.)J - +- S;[l = tang'(e2-k,.) 1/2 (5) Tri/dng hdp tong quat: Viec tinh toan tren hinh hpc phang ed the dugc md rpng cho nhieu tap nirt ne thang durng ^rIs:[l+tanr(e,-k,.)]" ^e? k, =arctang sinG; (7) N p^ z (6) eosB, Trudng hgp tdng quat, cac tap nirt ne va than gieng cd the ed su djnh hudng khdng gian chieu: He thdng nirt ne dugc xac djnh bang gdc phuang vj (9,) va gdc cam (a^) Than gie'ng khoan cung duge xac djnh bdi gdc phuang vj (k) va gde khoan so vdi mat phang ngang (8) Khoang each giua cac nirt 65 Hoi nghj KHCN 2000 "Nganh Dad Viet Nam trifdc them theky 21' ne theo hudng eua than gieng, khoang each bieu kien cua nirt ne (S,) theo hudng than gieng, dugc xac dinh bdi: S,=S, l+tang^(e, -k)+tang'(a, -6)]"^ (8) Ty le chan nirt ne theo hudng cua than gieng P''" la ham nghjeh dao ciia chieu day nirt ne bieu kien theo hudng than gie'ng: pk.S _ \_ S, l+tang^(0, -k) + tang'(a, -5) 1/2 (9) Vdi tap nirt ne, P^'* dat gia tri Idn nhat hudng than gieng vudng gde vdi nhung mat phang tuang duang tap nirt ne dd hoae hudng than gie'ng trung vdi hudng S" eiia tap nirt ne Oieu kien xay k = 0iVakhi5 = a , Viec md rdng cung tudng tu nhu bai toan phang cho hai hay nhieu tap nurt ne Dang tdng quat, ty le chan ddng chay nirt ne dugc tinh bang: p , ' " = z - T ^ — - — ! — _ 11/2 l + tang^(e,-kf) + tang^' ( , - , ) ] ' " i=i Ttr phugng trinh 10, hudng khoan (k„ 5,) cho ty le chan nirt ne Idn nhat Pj' (10)' cd the dugc xac djnh nhd may tinh Mdt each dgn gian, Idi giai eua bai toan ed the duge tien hanh nhu sau: vi gde phuong vj 9; va k, thay ddi ttr den 360° va dp ddc a, va §, bj gidi han khoang ttr den 90° nen Pj'' la mdt ham theo k( va 6, va gia trj ciia nd cd the dugc xac djnh tren may tinh KET LUAN VA M O T SO VAN 0£ TON TAI TRONG VIEC NGHIEN CtX) AP DUNG CONG NGHE KHOAN GIENG CO THAN NGANG, A NGANG TRONG KHAI T H A C DAU Cdng nghe khoan gie'ng cd than ngang, a ngang da va dang ap dung rdng rai d XNLD Vietsovpetro Cdng nghe da khang djnh vai trd cua chiing viec tang cudng khai thac cac via dau ma dac • biet la via dau da mdng nirt ne md Bach Hd Hieu qua eiia giai phap khdng dirng d viec tang cudng khai thac ma cdn gdp phan hoan thien he thdng gieng khai thac va bdm ep Tao dieu kien tan dung khai thac tai nguyen Idng dat mdt each hgp ly Hien nay, ddi vdi tang mdng md Bach Hd nghien ciru cac dae trung nirt ne ciia da mdng gan lien vdi su nghien ciru sutdn tai cae mien dat da maema khae nhau, su nghien ciru cac dac trung ciia dirt gay kien tao cung nhu viec tao nhtrng vting dap nat, nirt ne da ehira tang mdng Cae tinh toan hudng khoan nhieu trudng hgp mang tinh udc lugng, thuc te cae sd lieu nghien ciru cac dac trung nirt ne da ehira tang mdng md Bach Hd rat han che Trong tuong lai can thie't tang cudng nghien ciru theo hudng TAI LIEU THAM KHAO PTS Pham Huy Long, PTS Trinh Long "Nguon goc tao, dac diem nirt ne, dirt gay da mong granitoid viing mo Bach Ho, Rong va viing kecan" Bao cao de tai NCKH , Ho Chi Minh 1996 Vien NC&TK Dau bien, XNLD Vietsovpetro "Sa cong nghe khai thac va xay dung mo Bach Ho" 66 Hoi nghj KHCN 2000 "Nganh Dad Viet Nam tri/dc them theky 21' Vung Tau 1995 Vien NC&TK Dau bien "Hoan thien chinh xac hoa sa 66 cong nghe khai thac va xay dung mo Bach Hd", Vung Tau 1998 Richard C Nolen-Hoeksema and J H How/ard Estimating Drilling Direction for Optimum Production in a Fractured Resen/oir, The American Association of Petroleum Geologists Bulletin V 71 No (August 1987), P 958-966 Nguyen Van Gia XCr ly va phat then thong tin ve tham phuc vu thet lap mo hinh khai thac dau da mong mo Bach Ho Bao cao de tai NCKH, Hd Chi Minh 1997 67 ... BLTdC OAU TRONG VIEC AP DUNG CONG NGHE KHOAN GIENG THAN NGANG, A NGANG Tir nam 1995, d Vietsovpetro da tien hanh khoan gie''ng than ngang, a ngang, den taj md cd gan 30 gie''ng khoan cd than ngang. .. AP DUNG CONG NGHE KHOAN GIENG CO THAN NGANG, A NGANG TRONG KHAI T H A C DAU Cdng nghe khoan gie''ng cd than ngang, a ngang da va dang ap dung rdng rai d XNLD Vietsovpetro Cdng nghe da khang djnh... ciia he thdng gieng khoan thing dirng, qua trinh thie''t ke gie''ng khoan cac nha thiet ke da manh dan de xuat giai phap khoan gie''ng cd than ngang, a ngang cd tinh toan kha nang khoan djnh hudng