350 M6 hinh hoa bg trhm tich Oe tam Phii Khanh, ngoai khoi mign Trung Vict Nam MO HINH HOA BE TRAM TICH DE TAM PHU KHANH, NGOAI KHOI MIEN TRUNG VIET NAM Anders Mathiesen, Lars Henrik Nielsen Cue Dia c[.]
350 M6 hinh hoa bg trhm tich Oe tam Phii Khanh, ngoai khoi mign Trung Vict Nam M O HINH H O A BE T R A M TICH DE T A M PHU K H A N H , N G O A I KHOI MIEN T R U N G VIET N A M Anders Mathiesen, Lars Henrik Nielsen Cue Dia chdt Dan Mach vd Greenland Pham Van Tiem, Nguyen Thi Dau Viin Ddu Khi TOM TAT Bi trdm tich De tam Phu Khdnh, ngodi khai miin Trung Viet Nam la mdt bi m&l dugc thdm dd tim kiem vd chua cd mdt giing khoan ndo De ddnh gid tiim ndng ddu khi, mdt sd tuyen dia chdn tieu biiu da dugc minh gidi vd chuyin doi sdu di md hinh hod hi thdng ddu dung phdn mim md hinh hod be tich hgp ID vd 2D Mdt kiiu ria luc dia tieu biiu bao gdm cdc l&p trdm tich ddng tdch gidn vd sau tdch gian v&i cdu true vd Trdi ddt gidn diu da duge gid dinh Dgng phdn xg dia chdn chi rdng set dam hd vd than da dugc bdo tdn cdc dia hdo vd bdn dia hdo hudmg Bde - Nam tudi Oligocen - Miocen du&i Mdt nhimg vdn di l&n md hinh hod he thdng ddu bi Phii Khdnh la thiiu cdc dir lieu gieng khoan, vd de xdy dung mdt khung dia tdng vd ehinh xdc hod cdc sd lieu ddu vdo diing thdng tin md hinh la phdi dung su tucmg tu v&i cdc bi bin cgnh Sd lieu trudmg thdnh tir mdt sd giing khoan chon loc & cdc be ldn can da dugc diing di tdi uu hod liin chim vd lich sir ddng nhiet cua bi Phu Khdnh Lich su ddng nhiet, tru&c tien dugc xdc dinh dua trin hiiu biit khu vuc chung dung md hinh bi ID di tdi uu hod lich sir ddng nhiet Md hinh ddng nhiet du dodn dd duge diing ldm sd lieu ddu vdo cho md hinh hod be 2D Cdc kjch bdn khdc da dugc md hinh hod nhdm ddnh gid nhgy vd tdm quan ciia cdc tham sd ddu vdo vd chung cho thdy rdng ddng nhiet vd cdc tham sd ddng hoc la nhirng tham sd ddu vdo nhgy cdm nhdt dnh huong din tinh todn cdc mirc trudng thdnh vd sinh thdnh ddu khi, dd dia chdt vd dirt gdy cd thi cd dnh hu&ng l&n tdi kit qud dir&ng di cu Kit qua md hinh hod bu&c ddu chi rdng, cdc lcrp da me tiim ndng tudi Oligocen, Miocen du&i vd Miocen giira hien tgi dang & truong thdnh vd nhiet cao nhdt ki tir trdm tich, vd cdc l&p da me ddng tdch gidn Oligocen - Miocen s&m hiin & nhirng vimg rdng ldn ben du&i thim luc dia hien dang dugc chdn vui & sdu dii di tru&ng thdnh vd sinh ddu Kit qud md hinh hod du dodn rdng, ddu sinh tir dd me Oligocen dugc tich tu nhiiu cdu tnic dia phuong vd ddu cd thi cdn dang dugc sinh & phdn ria ciia cdc dia hdo ddng tdch gidn Trong phdn sdu ciia diin tich md hinh hod, th&i diim bdt ddu di thodt ddu tir dd me tiim ndng Oligocen dd xdy Miocen giira vd cd thi vdn cdn tiip tuc Tuygn tap bao cao Hoi nghj KHCN "30 nam Dau Viet Nam: Co' hoi moi, thach thiic mdi" 361 MODAU Be Phu Khanh la mot b§ dai va hep trai dai tij vT 14° Bae den 11° BSc ngoai khai ba bien mien Trung Viet Nam Chieu dai khoang 250km va rpng khoang 50km No co ranh giai a phia Tay vai them hep Da Nang, chia cat vai dia hao Quang Ngai a phia BSc bai dai trugt Da Ning, va vai be Cuu Long a phia Nam bai dai trugt Tuy Hoa (Hinh 1) Hinh 1: So vj tri be Phii Khanh, co- so- dir lieu va cac gigng khoan Tuyen dia chan 2D duoc chon de mo hinh hoa mSu do, vj tri digm 16 dku D5m Thi Nai mau xanh • • • 362 Mo hinh hoa bg trim tich De tam Phti Khanh, ngoai khoi mign Trung \igt Nam B I bao gom mot lap tram tich De tam day la muc tieu cua cac hoat dong tham khae tu nhimg nam 1970 Diem 16 dau a ba bien Dam Thi Nai va nhiing phan tich cho th4y d^u da dugc sinh tu set voi va bun set dam ho De tam (Nielsen va n.n.k., 2004; Bojesen_Koefoed va n.n.k., 2005) Mac du cho den chua co gieng khoan nao nhung cac dilm nong sinh dau ben ngoai cac cau tao la co the co Bai bao de cap den mo ta ngin gon khung canh dia chat, cac quan diem lua chon cac tham so dau vao \'a chien luge mo hinh hoa kem theo mot so vi du chi ket qua buac dau cua nghien cuu mo hinh bl thuc hien pha dau du an ENRECA (Nielsen va n.n.k., 2004) KHUNG CANH DIA CHAT VA LICH SU' PHAT TRIEN CUA BE Be Phu Khanh la mot be tach gian, dugc tao thod k>' Eocen (?) - Oligocen tach gian Bien Dong Nghien cuu dia chan cho thay mong bi phan cat bod nhimg dut gay, dia hao va ban dja hao dugc lap day bod cac tram tich dong tach gian phan each bod cac bat chinh hgp lan va dugc phu tren bod cac tap tram tich sau tach gian (Lee va Watkins, 1998; Huong, 2004; Huong va n.n.k., 2004; Huyin, 2004; Huyin va n.n.k., 2004; Thing va n.n.k., 2004; Boldreel va n.n.k., 2005) Tach gian va nang len hinh nhu da dien hoae tiep tuc mot so nod thod gian Oligocen muon va Miocen sam, va hien tram tich Oligocen va Miocen som cac be tach gian va tren cac doi nang giiJa cac be dugc phu bod 100 - 3000m trim tich Miocen giiia - De tu NTiu vay, cac tuyen dia chan da dugc minh giai va chuyen sang sau dugc cho la bieu hien cua ria luc dia tieu bieu bao gom cac tap tram tich dong tach gian va sau tach gian voi cau true vo Trai dat dong deu (Nielsen va n.n.k., 2004) Mo hinh luc so bo mod tien hanh lai cho thay rang, phan vo Trai dat a day phuc tap han nhilu voi nhung he qua can phai xem xet den xay dung mo hinh be tuang lai (Boldrell va n.n.k., 2005) Mang luoi tuyen dia chan thua, tu 10 din 20km, cung vai su phuc tap cua bl Phii Khanh chi cho phep ve dugc mot s6 it tap trim tich (Boldrell va n.n.k., 2005) Cac bit chinh hgp chinh da dugc ve va lien kit vai ca hai bl Song H6ng a phia Bic va Cuu Long a phia Nam, nhung khung canh va dilu kien dia chit khae da lam cho viec dinh tuoi tu>et doi ciia cac dia tang dung mo hinh rit kho khan Minh giai dia chan va ve tuang dia chin da dugc dung mo hinh hoa bl 2D, viec phan chia nho cac tap cac tuyen dia chin dugc chon dua tren cac nghien cuu noi bo ciia Vien Diu Khi (Huang, 2004; Huang va n.n.k., 2004; Huyin, 2004; Huyin va n.n.k., 2004; Thing va n.n.k., 2004; Boldreel va n.n.k., 2005) Chuyin ddi sau dugc thuc hien dua vao phuang trinh riit tu cac du lieu gilng khoan a phin phia Nam ciia bl Song Hong va be Cuu Long (Nielsen va n.n.k., 2004) Can cu tren tai lieu minh giai dia chan lich su phat trien kiln tao ciia bl Phii Khanh dugc chia lam ba pha: • Pha tdch gidn ddnh tir Eocen (?) - Oligocen din Miocen du&i - Iiic ma keo gian vo qua dat va toe liin chim dat cijc dai vao thai ky Oligocen va cac yeu to cau triic chinh da dugc hinh Trim tich song \ a dim h6 lip diy cac dia hao va ban dia hao CO tong chilu day tu 500 din hon 2500m Doi cho, cac dia hao dugc lip diy chii yeu bai cac tram tich biin ria va tuang paralic (Nielsen va n.n.k 2004) • Pha thir hai bdt ddu tu Miocen gida - su liin chim khu vuc thu dong co toe trung binh chiem uu the va-din tai qua trinh biin tiln bao triim cac ciu tnic dong tach gian Tuygn tap b^o eao Hoi nghj KHCN "30 nam DIU Viet Nam: Co' hoi mdi, thach thiic mdi" 363 • Pha thu ba dugc dac trung bing su liin chim t6c cao thai ky tu Miocen muon din De tu vai cac diirt gay thuan doc theo suon them, tai hoat dong doc theo huang ctia cac dai dut gay cii Mot he thong suon doc them vai su phat trien nhieu chu ky ciia cac he thdng trim tich trieu thap, bien tien va trieu cuang da dugc phat trien tu Miocen mugn din Ngoai dao dong nghieng khu vuc ciia be, khong co chuyen dgng kiln tao nao dang ke thai ky sau tach gian Dua tren minh giai dia chan, lat cat tram tich dugc chia hang loat tap dia chan phan each bang cac bat chinh hgp dia chan (Nielsen va n.n.k., 2004; Boldreel va n.n.k., 2005) Mot so bat chinh hgp co lien quan den cac su kien kien tao va dugc lien ket voi cac bat chinh hgp khu vuc cac gieng khoan be Ciiu Long va be Song Hong (Andersen va n.n.k., 2005) Nhimg bat chinh hgp da dugc lien ket tren toan be Phii Khanh: • Mat phan xa mong (Top BSM) dugc nhan biet nhu mgt mat bat chinh hgp bao mon, danh dau bat dau ciia pha tach gian chinh va thai k}' tram tich be • Bat chinh hgp noc Oligocen (Top Oli) danh dau ket thiic giai doan trim tich chinh cac ban dia hao va bat dau tram tich bien • Bat chinh hgp noc Miocen duai (Top LM) la bat chinh hgp phan chia hai tap trim tich dong tach gian va sau tach gian Bat chinh hgp noc Miocen duai dugc tao bai su thay doi dieu kien kien tao tu che cac dirt gay khoi tang xoay va liin chim chiem uu the sang che liin chim khu vuc deu dan va tram tich bien chiem uu the • Bat chinh hgp nho Miocen giiia tuang iing vai pha tach gian thu hai No dugc xac dinh bai nghich dao tung phan cac cau tao vung suon them va ria cua be, toe liin chim trung binh vai moi trud'ng tram tich bien chiem uu the • Bat chinh hgp noc Miocen giira (Top MM) danh diu khoi diu ciia tram tich manh vun toe cao, do sau nuac bien tang nhanh, bat dau ciia pha tach gian thu ba Nhirng nem nghieng tien ve phia Dong va phu thuan len mat bat chinh hgp co day tram tich ven bien va them Ion dan ve phia Dong Qua trinh tien lan ro rang cua viing ven bien va them co lien quan den su tang nguon cung cap tram tich gay nen boi qua trinh nang len va bao mon rong khap cua mien Trung va Nam Viet Nam tir Miocen giira den (theo Carter va n.n.k., 2000) MO HINH HOA B £ Qua trinh sinh dau tir da me tiem nang khu vuc nghien cuu da dugc tien hanh tir viec lap ban cau tao va phan tich tuong dia chan va dugc chinh sira theo so lieu gieng khoan va dugc danh gia bang \'iec sir dung phan mem tich hgp mo hinh hoa be ID, 2D: lES PetroMod Phan mem mo hinh hoa be dinh lugng va mo ta tat ca cac qua trinh quan nhat cua be nhu la mot ham ciia thai gian, va nhu vay sir phat trien ciia be dugc xac dinh duai dang cac dan vi thdi dia ting, goi la "ldp md hinh" hoae "sir kien" Sd lieu ve trudng tir mot sd gilng khoan a cac bl lan can da dugc diing dl tdi uu hoa qua trinh lun chim va lich sir dia nhiet bl Phii Khanh Lich sir ddng nhiet dugc xac dinh tren co sd hieu bilt chung khu vuc va sd lieu gilng khoan qua viec sir dung md hinh ID de tdi uu hoa lich sir ddng nhiet khu vuc Sd lieu tir hai gilng khoan M6 hinh hda bg tram tich De tam Phii Khanh ngoai khoi mign Trung Viet Nam 364 114-KT-lX d Nam bl Sdng Hdng va 03-lX d phin Bic be Nam Cdn Son da duoc diing dl tdi uu hoa hai lich sir ddng nhiet vdi gia thiet rang hai gieng khoan cung cap dai biin ddi hgp ly vl trudng va tham sd dau vao cho be Phu Khanh (Nielsen va n.n.k 2004) Cac md hinh ddng nhiet da tdi uu hoa dugc diing cho md hinh 2D ciing vdi nhimg hieu bilt dia chit thu dugc tir md hinh ID Cd tuyen dia chan phan bd tren cac khu vuc cd triln vong nhit ciia bl Phu Khanh da dugc lira chgn de md hinh hoa (Hinh 1) Xac djnh sy kien ciia mo hinh Viec xac dinh sir kien va thdi dia tang da dugc tdng hgp tir cac tai lieu dia vat ly dia chit cua bl Phii Khanh va cac be lan can nhu Nam be Sdng Hdng, Nam Cdn Son va be Ciru Long Su phat triln ciia be De tam dugc chia mdt sd pha kien tao nhat dinh phan each bing cac bit chinh hgp phat trien rdng khap be Nghien cuu ciia Vien Dau Khi vl thdi dia ting d cac gilng khoan da dugc sir dung cho md hinh ID Tuy nhien, thdi dja tang cho md hinh hoa be 2D bao gdm tdi 12 su kien da dugc chgn tren co sd minh giai cac mat phan xa dia chan chinh va tham khao thdi dia tang d cac gieng khoan d cac be lan can (Bang va Boldreel va n.n.k., 2005) Bang 1: Xac dinh su kien cho mo hinh 2D 6' be Phti Khanh o Su kien Mat phdn xg • Tap dia chdn • • Tdng dia chdn Khodng (don vi) Tudi (Ma) Daybiln-SB8-U 1,5-0 Bdomdn Khdr^ trdmtid% (Ma) Day bien e m SB8 85 SB8-SB7-U , - 1,5 SB7-UM-U 4-2,5 UM-SB5-U 8,5-6 SB7 ^ SH5 s A Noc UM = (Bat chinh hop) S4 a 4-Jun t 23.25 Y 151 45 Valua: 027 |%Rol Hinh 3: So- chon viii 6' GK 114-KT-lX vol phan viing tru-o-ng theo phan xa vitrinit (xem ky hieu d Hinh 5) Chi co da me du-ffc to mau Qua trinh md phdng sinh dau nghien cim dugc gia thilt coi ehudi phan irng chuyen hoa vat chat hiru ca dau cd dang kerogen -^ diu —>• Dilu tuong ung vdi mdt "md hinh ty le don" (cd nghia la mdt pha ldng thuin bao gdm mdt phan "dau" don le va mdt pha chi gdm mdt phin "khi" dan le) Qua trinh sinh dau dugc xac dinh tir md hinh ddng hgc theo Tissot va n.n.k (1988) hoae Tissot va Espitalie (1975) dd gia dinh phin diu sinh chi cd "diu den" va "khi khd" va da me tilm nang chira ca kerogen loai I, II lin kerogen loai III Md hinh ddng hgc cua Tissot va n.n.k (1988) khdng md phdng kerogen loai I thuan Ca hai md hinh ddng hgc diu gia dinh phan img gian don chuyin ddi tir diu chir khdng true tilp tir kerogen Dilu din tdi ca hai md hinh se chi sinh d che nhiet cao Hinh cho thay ket qua md hinh ID sir dung phan viing diu vdi md hinh ddng hgc Tissot va n.n.k (1988) tai gilng khoan 03-IX gia dinh da me chira kerogen loai II Chu y la d khu vuc cua b l Nam Cdn San phin dudi ciia tap da me day 2000m "Oli SR-Unit" khdng phan chia da vao cira sd tao diu chinh khoang 25 trieu nam trudc (viing ldng) tai phin dudi va 12 trieu nam d phin tren Phin dudi vao viing sinh (viing khi) d khoang 17 trieu nam trudc Cdn phin tren vao vimg sinh khoang trieu nam trudc va hien toan bd ting da me dang d ddi qua trudng (Hinh 4) 371 Tuygn tap bao cao Hoi nghj KHCN "30 nam Phu Viet Nam: Co- hoi moi, thach thtic mdi' XLJi oodiimtmimiitaMmmimiiiaaMEiiMiu Fie Efli View Panel Toote Help k A^'€fDEF lWNDEF~tlUlilOEI=T^ Hinh 7: Mo hinh 2D tuyen dia chan huong Bae - Nam VOR-93-301 vo-i phan viing truong theo phan xa vitrtinit ff thoi diem hien tai Phan xa vitrinit duoc chia va to mau theo phan viing truong va theo gia trj bien quy djnh chung (xem Hinh ve ky hieu) Chii y chi co nhirng khoang da me duoc to mau » V O R - - - - ( B l l _ l - PetroView2D - i r : \ A n M _ \ R e f _ M o d « l s _ \ P K B 9 D t e H i IFHe Overlay Penel View Settings Tools Models Help | v » « i « r T n j AFlair MIAiisằ2ằ)lolôô4S ãã i ã : SweeneySBumham( 1990LEASY%Ro /14 00 t^ta - Even!_6 200000 257500 Distance [meter] S»«eney!.Bumliam(1990)_EASY%Ro [%Rol IM B L O EO B M G 3BM0 ^ PosWfflure R&a(J/ 115 16ia7n 717174 Tfi 3132 ?.3M 36 as 19 40 4743 45 47 435? I C e l l « W D E F X: 161^6737 V -566 19VaJije(sl.*JNDeF(WoI Hinh 8: Mo hinh 2D tuyen dia chan VOR-93-301: mo hinh di cu va tich tu dau thoi Miocen som Mui ten (xanh: dau, do: khi^ chi huong va Ion dong chay dau diing mo hinh dong hoc Tissot va n.n.k (1998) 374 M6 hinh hoa bg tram tich De tam Phii Khanh ngoai khoi mien Trung Viet Nam * V O R - - - - l o a l ) - PetroView20 - fin;\Vietnam.Mart5a4\Ref_Mocl(?h_2\PKB_09090J_Mai>pm2dl Fdt ^ M y Pirtl ^ w Settirg* Tool* Models Help _ Jelj