NGHieN CLTU TRfiO BOI PHAN VUNG CAU TRUC VA Sff BG VE TRIEN VGNG DAU KHl KHU VUI! BE TV CHlNH V O N G MAY ThS LE DUfC CONG PGS TS NGUVfeN TRQNG TIN Vi«n D^u khi ViSt Nam f STDUCTUDAL FEATUDEA AND PDEL[.]
NGHieN CLTU-TRfiO BOI PHAN VUNG CAU TRUC VA Sff BG VE TRIEN VGNG DAU KHl KHU VUI! BE TV CHlNH - V O N G MAY ThS LE DUfC CONG PGS.TS NGUVfeN TRQNG TIN Vi«n D^u ViSt Nam f STDUCTUDAL FEATUDEA AND PDELIMINADY ETDOIEUM DISTD15UT10N ADEA DEGIONAL OF TU CHINH-VUNG MAY BASIN Tu Chinh • Vung May hasin area is the deep waters offshore, an area of approximateiy 150,000 W Search activities in oii expioration In tlie area in recent years has been more interest and seismic surveys and geological studies and evaluation of mineral potential, especially oil and gas potential Characteristics of the geological structure of Tu Chinh - Vung May basin and surrounding is very complex, not yet shed light on the overall picture of the geology and mineral potential Also sea water depth in the area varies from several tens of meters at the beach several hundred meters underground and deeper from 1,000 • 2,800 m also affect survey worl( and research In this article the authors sum up and analyze geological structural features of the area Tu Chinh - Vung May is based on the results to the present time to address areas of potential oil prospects gas Result interpretation 20 seismic data for the entire area Tu Chinh • Vung May basin maps shown through the establishment of new structures include: a map Pre-Tetiary Basement, Oligocene, Miocene lower, middle Miocene and Miocene on The main fault systems Include: Systems North East - South West, A system of longitude, A system of latitude and systems North West - South East Based on research, meta-analysis of geological structures, the authors separated the areas of Tu Chinh - Vung May into main structural units: Zone of Nam Con Son basin northeast; Zone of Spreading bottom ol the East Sea; High zone of Tu Chlnh - Phuc Nguyen - Phuc Tan; Vung May basin; High zone of Da Lat - Da Tay and High zone uf Vung May - An Bang and regional oil and gas potential high northeast Nam Con Son basin and Vung May basin Oat van de B8' TU Chinh - Vung May la be tram tich nudc sau xa bd, dcio gan dat lien nh^t la d^o TrUdng Sa each vjnh Cam Ranh 450 km, dcio Phu Quy 400 km; khu vuc nghien cdu cd dien tich 150.000 km^ vdi vj trf dia ly: iii 6°15' den 10»10' vT dd Bac va 109°15' den 113»35' kinh da Bdng, bao g6m dien tich cac 16 130 den 136, 155 den 160 va 80-185 MUc nudc bien khu vUc nghien cdu thay doi tu vai chuc met tai cac bai ngam den hang tr§m met va sau hdn d§'n 3.000 m; dd, phan Idn dien tich cac 16 133, 134, phan Tay Bac 16 135, ph^n Tay Id 157 va gdc Tay Bic id 158 CO muc nudc bien ndng hdn (dudi 1.000 m) ton tai cac bai da ngam, bai can nhu Vung MSy Huyen Tran, Que DUdng Phuc Nguyen va TU Chinh Cac dao va bai ngam da s6' la 6iQ san hd phat then tren cac kh6'i nho cao hoac trdn cac kh6'i nui iCfa thoai hoa C6ng tac nghien cdu dja chat - dja vat IJ tai khu vi/c TU Chinh - Vung M&y da dUdc bat dau tU nhOng nam 70 cija the ky XX, hien cdng tac nghien cUu, t)m kiem tham dd d^u da dddc khSo sat vdi mang iudi khio sat dia chan 2D dUdc phu kha chi tiet vdi khodng 30.000 km tuyen Cac nghien cdu dac dilm dia chat cua khu vUc dUa tren cac tai lieu khao sat dja HewilOim Sathang8.2012jQ.jOA H O C NGHieNcQu-TRnoedi chat da dupc thi/c hi§n tif nam 1993 d§'n vd khu vuc nghi§n ctru da dapc md rdng, bao g6m mOt phan qu^n dSo Trudng Sa Pliiroiig phap nghien cira Di nghiSn cdu vd ddnh gi^ sd b$ li^m nang d^u cua khu vi/c ndy, cdc \dc giS da sCr dgng cdc phddng phdp nghidn cdu sau: - Phddng phdp dja chain d|a tSng, phUdng phap dia t^ng phan tap mmh giSi tai li$u dja cha'n - Phddng phap tdng hpp danh gia ti^m nang d^u Ket qua nghien cihi D$c diem cau true vd h$ thing ddt gay Trong nghiSn cdu dac di^m Ccfu true cua khu vi^c, cac bkn cliu true da dddc sii dgng, nhidn pham vi bai via't nay, cac tac g\k sCf dgng bdn ca'u true nde mong trudc Oe Tam Noc mong trudc De Tam la mdt ba't chlnh hdp khu vgc ldn, song phdn xa co bidn dd manh, liSn tge td't, ben dddi no la cac phdn xa tr^ng hoac hdn ddn; ddi cho la eac phan xa phan Idp cua cae t^o trudc De Tam dd theo doi trdn eae mat eat dia chan d cdc khu vgc trung sau hoae cdc dia hao, bdn dia hao (hinh 1) Kd't qud th^ hidn r5 c^u true nde mdng trudc Kainozoi vdi dO sSu thay ddi tCr khodng hdn 2.000 m cde khdi nhd nhU Td Chfnh, Vung Mdy, phfa Tdy va Ddng khu vgc nghidn cdu d^n khodng hdn 10.000 m cac trung sau thu0c phfa Tdy, Tdy B^c vd phdn trung tdm, phdn Ddng khu vUc nghidn cdu, Tuy nhidn, dO sau mgc nude biln thay ddi ti/ vai chgc mdt dd'n hdng nghin mdt Trdn bdn dd c^u true cua m§t mdng ndy chung ta th^y tdn tai h$ thdng ddt gay chfnh eua khu vgc nghien cdu Cdc h0 thdng diJt gay quan sdt qua cdc mat c^t dja ch^n thdy phat tridn td trddc Eoxen - Oligoxen ddn hdt Mioxen giQa quy md phat tridn khde cd v6 chidu ddi cung nhu bidn dd Khu vuc nghidn cdu tdn tgi hd thdng dift gay: - Hd thing din gay phddng Ddng Bic - Tdy Nam: ehiing phdt tridn rdng khdp khu vUc nghidn cdu, hogt ddng mgnh thdi gian Oligoxen va Mioxen dudi, sau dd tdi hogt ddng vdo Mioxen giOa rdi gidm ddn cudng dp vd ngC/ng vao cudi Mioxen mudn Ddy la hd thdng ddt gay chinh khdng ehd hinh thai edu true Chung cua todn khu vgc, hau hdt Id ddt gay thudn, ddpc hinh vd phdt trien trudng Ung sud't tdch dan theo hudng Tdy Bde - Ddng Nam (vudng goc vdi trge md rpng Bien Ddng) vdo thdi ky Eoxen (?) - Oligoxen Cgdng dp hogt ddng cCia hd thdng cdc ddt gay rd't manh, tgo ndn cac dja hdo, bdn dia hao va cdc dja luy, bdn dja IQy xen ke - Hd thing diit gay d kinh tuyin: phdt trien phdn Tdy Nam vd phdn Ddng khu vgc nghien cdu Id ddt gdy thudn, hogt ddng theo cd ehd cdng dan, cd bidn dd ldn tdng mdng, Oligoxen va gidm ddn Idn cdc tdng trdn Chfnh cdc dCft gay ndy da lam chuydn djeh cdc dift gay dupc hinh td trUdc, ddng thdi Idm thay ddi hinh thdi edu true cQa bdn thU cdp Oligoxen d mdt sd npi (dac biet phan phfa Bdc) H§ thd'ng dCft gay ndy dupc hinh vao cudi giai dogn tgo rift sdm (Oligoxen), dau giai do?n tgo rift mudn (Mioxen dudi) va tidp tgc hogt ddng sudt Mioxen giiJa - mudn, mdt sd ddt gay k6o dd'n Plioxen Hinh 1: bin dd ciu true nde mdng Irudc Kalnozoi khu vUc nghiin ciiu «" KH^AHc5cS^^^^"9«-20i2 - Hd thing dtit gay d vi tuyin: phdn bd chO yen d phdn Dong Nam khu vue nghidn cdu thudc phfa Bdc ddi trung Tdy Vung May, phan giOa ddi ndng Vung May - TrUdng Sa Day Id cde dOft gay thudn, dupe hinh trudc giai dogn tgo rift vd phat tri^n kdo dai ddn het giai dogn tgo rift, quy md phdt triln cug hd thdng dLift gay ndy khdng ldn NGHI6NCLrU-TRROD6l - Hd thing diit gay Tay Bae - Ddng Nam: hd thdng ddt gay phat tnen chCi ydu ve phfa Ddng Nam khu vgc nghidn cCfu, chung hinh su phat tridn xoay cua he thdng dUt gay d kmh tuyen luc hut eua khdi sgt lun cua be Natuna, chung phan chia cdc cau true khu vgc ndy ed hudng Tdy Bac- Ddng Nam ; =i i : - Lich sLiphat triin dia ehit: qud trinh hinh thdnh, phat trien cua khu vuc gdn lien vdi lich si!f hinh thdnh va phdt tridn Bien Ddng Kd't hpp cdc ket qud nghien cUu cua ede khu vuc ian can va tdng hdp cac tdi lieu khu vgc nghien cdu chung tdi thay rang, khu vuc nghien cUu dUdc hinh thdnh vd phdt tridn gom cdc giai dogn: trUde tao rift (Pre-rift), ddng tao rift (Eoxen - Mioxen sdm) vd sau tao rift (Mioxen mudn -DdTU) Ss BS :::::£'=•='- IIII Dgc diem dja cha't va phan vung cd'u true Be TU Chfnh - Vung Mdy nam khu vgc cd cac ydu td ea'u - kid'n tgo hd't sUe phUc tgp, hinh tren mien cau true Igc dia sdt qua trinh dgi dudng hod Biln Ddng Do qud trinh vdn ddng kidn tao, sg tUdng tdc cCia cdc mdng trdn thdm Sunda da hinh thdnh mdt logt bd trdm tich kidu rift sau cung vdo cudi Mesozoi (?) ddu Kainozoi nhU cdc be vinh Thdi Lan, Malaysia, Ddng va Tay Natuna, Sarawak, Brunei, Sabah va eac be d Nam Viet Nam, CO bd TU Chinh - Vung May Cae bd trdm tfch ndy dupe hinh thdnh, phdt trien chu ydu trdn mien vd Ige dja hoac v6 Igc dia chuyen tiep i:Z7i l l l \ ( II \H}I -=^'— I ; ' ,,., ,.„™, „, ::-V-V-v: I**wa f^tf \ ;^ ;;;,!:•::.;::•;-::., I":::?;:::;"-'" Eir'":;;;:,••••"• \ r.f"- '^:::::"^T"" , , :~: ••,••'••^^'IM''™''"' [ng.,,, E3> llml} : ((if ,1 - Dde diem dia ting trim tieh: ede tao tram dia chat, chung ta cd the phan chia khu vUc nghien tfch khu vgc nghien cdu dupc tdng hpp tU ket qud cuu cac don vi cau true sau (hinh 3): cCia gidng khoan PV-94-2X kdt hdp vdi eac gidng khoan cOa be Nam Cdn Son cung vdi kd't qud minh gidi tai lieu dja chan khu vuc cho thay, tram tich khu vLfc nghidn cUu dUpc phii trdn da mdng, gdm tram tich Igc nguyen cd tudi tU Eoxen (?) - Oligoxen ddn hien tai Lat cat tram tfch tdng hdp gdm da mdng trudc kainozoi vd tram tfch Kainozoi (hinh 2) - Phin vung ca'u tnic: khu vUc nghien edu gdm cac ddi nang vd trung ndm xen ke, phdt tridn theo hudng Ddng Bdc - Tay Nam Ddi ndng cao dapg khdi - dja luy hogc khdi dirt gay cd Idp phCt tram tich Kainozoi ddy khoang 3.500 m Cac trung ed dang dia hdo, bdn dja hdo dUdc Id'p day bdi tram tich Kainozoi vdi bd day dgt td 6.000 den 8.000 m Dua trdn cdc dde diem ve cdu true, he thdng dpt gay, dgc didm vd tram tfch va qua trinh phat trien Hinh 3: cac ydu td cSu trUc chfnh cua khu vuc nghidn cUu Hoat dong So thang 8.2012 j g ^ Q ^ HQC NGHieNCQU-TRfiODfil -h Ddi Ddng Bdc bi Nam Cdn Sdn: ddi ed hudng cd'u true gdn nhU B^c Ddng Bdc - Tdy Tdy Nam bd ddy trdm tfch Kainozoi dgt tdi 7.000 m M$t dO ddt gay cCia ddi ndy tUdng ddi ddy, chdng t6 nd bj Anh hudng mgnh bdi kidn tgo tdch ddn Biln Ddng kdt thuc vdo trudc Mioxen giufa Ddi ndy dupe ehia thdnh hai phg ddi gdm: phij ddi ndng, chid'm phdn ldn didn tfch phfa Tdy cdc Id 129-131 (trong phg ddi ndy, cdc dUt gay phdt tridn chu ydu theo hudng Ddng Bdc - Tdy Nam); phij cdc ddi trung, phgm vi phfa Tdy cde Id 131 132 gdm cde dja hdo, bdn dja hdo nhd phat tridn theo hudng Tdy Bdc - Ddng Nam trung vdi phUdng cua ede dUt gay mdt sd nPi quan sdt thdy hogt ddng nui Itfa trdn mdt cdt dja chd'n -f Ddi ndng Dd Ldt - Dd Tiy: ndm d phfa Ddng khu vUc nghidn cifu, ed cdu true bj phdn dj manh Oligoxen, dde bi0t Oligoxen sdm, chidu ddy trdm tfch thay ddi ddng kd ta 2.000 ddn 5.000 m Dde didm cdu triic cCia ddi ndy chCi ydu theo hudng Ddng Bdc - Tdy Nam vd chju dnh hudng mgnh cCia qud trinh tdch dan Bidn Ddng, hogt ddng nui ICfa trd vdo thdi ky cudi Mioxen ddu Plioxen lam phd vS cdc edu true da dupc hinh thdnh trUdc dd, iam cho cdu true d khu vgc da phiirc tgp Igi cdng phife tgp hPn, + Ddi dan ddy Biin Ddng (cdn ggi Id trung siu Biin Ddng d Ithu vi/c TU Chfnh - Vung Mdy) la phdn keo ddi vd phfa Tdy Nam cCia vimg tdch dan ddy Bidn Odng Be ddy trdm tfch Kainozoi, dde bidt trdm tfch Neogen rdt mdng, khodng 800 ddn 1.000 m phu ke dp Idn tram tfch ed hdn ve phfa ranh gidi cua ddi Be mdt ddy bien tUPng ddi bdng phlng, khdng quan sdt thdy hogt ddng nui iCfa Cdc dift gay chu yeu cd hudng Ddng Bde - Tdy Nam, ridng dUt gay phia Nam cd hudng a v7 tuye'n vdi bidn dd djch ehuyen khd Idn, khodng 700-800 m + Ddi ning Vung Miy - An Bang: ndm d phfa Ddng Nam, Id mdt ddi ndng tUPng ddi dn djnh, dupc edu tif cac khdi ndng ndm xen ke va phdt tridn theo hudng Ddng Bde - Tdy Nam, be day trdm tfch Kainozoi mdng Cdc dUt gay cd hudng Ddng Bdc - Tdy Nam, Odng - Tdy vd a kinh tuyen ehu ydu la cac diift gay trd, mdt sd dift gay cd tdi hogt ddng Igi sau ndy Trong ddi nay, tdn tgi mdtsd ndng dja phUPng nhu ndng VOng May, nang Trddng Sa bidu hien niii lira cd le hinh Plioxen - Dd Td + Ddi nang TU Chinh - Phuc Nguydn - Phuc Tin: gdm cac Id 132-134 vd mdt phan nhd cdc Id 155, 156 Trong cde tdi lidu nghidn cUu trudc ddy, todn bd didn tfch cua ddi ndy dupe gpi Id "ddi nang ria" Cau true ddi nang phUc tgp, cd dgng khd'i phdn cdt bdi nhidu ddt gdy chu ydu theo hudng Ddng Bdc Tay Nam va tdn tgi nhieu edu tgo dgng dja luy phdn ria Ddng cua ddi, mdt sd nPi ed mat hogt ddng nui ICfa eua cac giai dogn khae Trong pham vi ddi cd nhidu ddi ndng da ddpc ddt ten nhu ndng Tu Chfnh, ndng Phuc Nguydn, ndng Phiie Tan, ndng Huydn Trdn, trung Bdc TU Chfnh, trung Ddng Tu Chi'nh, trung Tdy Phue Nguyen Tidm ndng diu eua khu vijc: vdi khu vUc nghien ciifu mdi ehf cd mdt gid'ng khoan trdn ddi ndng, vdy cdc nghien eUu vd dd sinh, chda, chdn, bdy ddu dga vdo kdt qud tdng hpp eua gidng khoan va mdt sd gidng khoan phfa Dong Nam Cdn Son Dd sinh gdm cdc dd Oligoxen vd Mioxen sdm ed ngudn gde tU thUc vdt bdc eao (kerogen logi lli), l^ng dpng mdi trudng tam gidc chdu, bidn ven bd oxy hoa, khCf ydu vd cd ngudn gd'c dam hd (kerogen logi II), ldng dpng mdi trUdng ddm hd dudi didu kidn khCf va khQ ydu Dd chifa: tren cd sd tdng hpp tai lieu eho phdp dg bdo khu vgc nghidn cifu tdn tgi cac logi da chiifa: da chda mdng nCrt nd phong hod trude Kainozoi, dd chda cat kdt tudi Oligoxen, da chda cat kdt tudi Mioxen Dd chdn: khu vgc nghidn cii'u tdn tgi tdng dd eh^n: da ch^n dja phUdng (Id ede tap trdm tfch Oligoxen, Mioxen) vd da chan cd tinh khu vUc (la trdm tfch Plioxen sdm) tdp trung ehu ydu d phfa Nam khu vUc nghien cufu Bay chiifa: tdn tgi logi biy la bdy cau tgo va bay dja tdng + Trung Vung Mdy: ehid'm phan Idn d ede Id tii 157 ddn 160, bd ddy trdm tfch Kainozoi dgt tdi hdn 9.000 m He thdng diift gay cd hudng Ddng Bdc Tay Nam, d vT tuydn, mdt sd cd hudng Tay Bdc Ddng Nam phfa Nam cua trung Cdc cdu tgo phat tridn kd thCfa trdn cdc vi dia luy ddu cd didu kidn thudn Ipi ve trien vpng dau khf dde bidt cac cd'u tgo kd cdc dja hao hinh giai dogn ddng tram tfch Hogt dpng ddt gay pham vi cua ddi ddu kdt thuc vao trude Mioxen giOfa Phfa Tdy cua ddi 82 K H O A H O C ^° ^^^"9 ^-2012 Phan vOng trien vgng dau Vimg tridn vpng ddu khf ciJa khu vgc dUpo danh NGHI€N cufu-TRRO DOI gia tren sd sd cdc chT tieu sau: dde trUng ve cau - kien tgo; mdc dp trudng cua vat chdt hOu cd, didn tich va be ddy phdn bd dd sinh hydrocarbon, vimg eung ca'p va hudng djch chuyen dau khf; phgm vi phan bd, quy md va so lupng eac cdu tgo trien vpng; mdc dp rui ro ve he thdng ddu khf (sinh, ehUa, chan, bdy, thdi gian) Qua vdo eac tidu chf phdn logi ndu tren, nhdm tdc gid da xdc djnh dupc cdc khu vgc (hinh 3): Vung c6 triin vgng diu cao: Id don vj ed'u true trung Vung May, vung cd mdt ddy dO cac tap hpp tridn vpng ddu khf vd hdu hdt cdc cd'u tgo tridn vpng deu phdt tridn kdthUa khd dn djnh tif mdng trudc Kainozoi ddn hdt Mioxen giOfa; ddng thdi, ede cd'u tgo ddu ed kha ndng ngp ddu khf thuan Ipi So sanh eae didu kien dja chat dau khf cua Malaysia, Brunei eho thay, cae eau tao phfa Nam cua khu vgc nghien edu ed tridn vpng tfch tg dau khf cao Vting triin vong diu tot: tgp trung d ddi Ddng Ble bd Nam Cdn Sdn va ddi nang Da Lat - Da Tay Hau het cdc cd'u tgo deu nam gan vdi da me dang d thdi ky tao dau, vi vdy kha ndng ngp bdy thudn Ipi Rdi ro Idn nhd't la mdt so khd'i xdy dm tieu san hd tudi Mioxen giufa - mupn, thidu ving tdng chan Vung triin vgng diu trung binh vd vung triin vgng diu thip: chung bao gdm cae ddn vj cdu true edn Igi khu vUc nghien ei^u Ket luan Tren cd sd tdng hpp vd cap nhat kdt qud nghidn cdu, phan tfch vd ddnh gid tdng hpp cac tdi lidu dja chat, dja vat ly cua khu vgc nghien cifu va ian can, nhdm tdc gid dua mdt vai kdt luan: Ljch sii phdt trien dja chdt cua khu vuc nghidn cUu ddu trdi qua giai dogn ehu ydu: trUde tgo rift, ddng tgo rift, sau tao rift Bd day trdm tfch cCia khu vUe dgt tdi 9.000 m cdc trung, dja hao, ban dia hao va tudi tgo eua chung tif Eoxen (?) den Oe TU Cac trung phan bd d khu vgc phfa Tdy, Ddng Nam va mdt phdn trung tdm Khu vUc nghidn cdu tdn tgi hd thd'ng dUt gay chfnh: Ddng Bdc - Tay Nam, a vt tuydn, a kinh tuydn vd Tay Bdc - Odng Nam; ehu dgo vd chi phdi cdc hogt ddng kidn tao cung nhu cdu true la hudng Tdy Bac - Ddng Nam va mdt phdn a vTtuye'n, d kinh tuydn Trong khu vUe TU Chfnh - Vung May, da mp Id set tuoi Oligoxen tgo mdi trddng dam hd vd mdt phan tram tieh hgt mjn tuoi Mioxen sdm thdnh tao moi trddng bien Vdt chd't hOu CP cd Keorogen loai II, III, phdn Idn dang d pha tgo dau Bd chUa gdm eac tap eat ke't xen ke tudi Oligoxen, Mioxen va am tidu san hd Da chan Id cac tap set xen ke tUdng Ung tudi Oligoxen, Mioxen; d mdt so trung cd the tdn tai tang set khu vuc tudi Plioxen Bay chUa chfnh la dgng vdm, ban vdm cat kdt, khd'i xdy am tidu san hd vd cd the ca khdi mdng niift ne Qua viec phan tfch, ddnh gia, chiing ta da xdc djnh, phdn ehia dupe eac ddn v| eau true ehfnh cOa khu vUc be TU Chfnh Vung Mdy gdm: ddi Ddng Bac be Nam Cdn Sdn; ddi dan day Bien Ddng; ddi ndng Tu Chinh - Phuc Nguyen - Phuc Tan; trung Vung May; ddi nang Da Ldt - Dd Tdy; ddi ndng Vung May - An Bang vd da phdn chia dupe cdc khu vuc ed tridn vpng ddu khf • Tai lieu tham khao PVEP-EXP/TC06-005: B^o c&o "Minh giSi \i,\ W&u