Hoi nglij KHCN 2000 "Nganh Dau khi Viet Nam trifdc them theky 21'
Q,kQ, DANG DOI TLfONG CHCTA KHI HIEN CO VA P H A N B O TRUr LLTONG C O A CHUNG 6 VIET NAM
Le Van Truang, Vu STLy, Nguyen Tien Long Cong ty Giam sat cac licip dong chia san pham Dau khi
TOM TAT
Trong nhffng nam gin day ehung ta ed nhieu phat hien khi khdng chi trong cac tang ehffa hat vun ma cdn trong da cacbonat tuoi tff Mioxen den Plioxen. Cae md khi dugc tim thay chii yeu a cac be Sdng Hdng, Nam Cdn San va Ma Lai - Tho Chu. cdn cac mo diu chi dugc phat hien d be Cffu Long.
dbe Sdng Hong, cac doi tugng ehffa (play) khi gdm: trim tich delta tuoi Mioxen, cat ket tuoi Mioxen mudn, Plioxen cd trff lugng khoang vai tram ty m^ (BCM) vdi ham lugng CO2 cd vai ehuc phin tram. , .' : •,
dbe Nam Cdn San, hai doi tugng ehffa khi chinh la: cacbonat tuoi Mioxen trung - thugng va cat ket tuoi Mioxen ha - thugng. Doi tugng ehffa cacbonat thudng phat trien tren cac ddi nang. Cac ting ehffa hat vun ed dang Idp hoac than eat hinh thanh trong mdi trudng delta effa sdng hoac ven bien. Trff lugng khi trong eae doi tugng ehffa nay ca khoang vai tram ty m^ vdi ham lugng CO2 thap.
dbe Ma Lai - Tho Chu, khi dugc phat hien trong cac Idp cat ket Mioxen mdng cd trff Iffgng ed vai ehuc BCM.
Ben canh dd, lugng khi dong hanh cd the lay dugc tff cac md diu dang va se khai thae cung rat Idn.
Tit ca nhffng dieu dd se dua Viet Nam trd thanh mot quoc gia cd tiem nang Idn ve khi a khu vue trong vai nam tdi. Hien nay, Viet Nam da xac dmh dugc thi trudng khi hien tai phue vu ke hoach trudc mat dua so md khi vao khai thae Trong nhffng nam sau, thi trudng khi can dugc md rdng han phu hgp vdi mffe do tang trudng ciia eae hoat ddng tim kiem, tham dd, phat then md va san xuit khi a Viet Nam eung nhu trong khu vue.
Gidl THIEU CHUNG ' • - -^-^^ ' - ' Bai bao de cap den tiem nang khi cua ba be chu yeu chira khf chfnh la: Song Hong, Nam Con Son va Ma Lai - Thd Chu. Trong pham vi cac be nay da cd 170 gieng khoan tim kiem, tham dd vdi ket qua la ed 66 phat hien, trong ddcd mot sd trd thanh mo khi. ' -•': M i;^;...! ••.:.•
Oe lam rd tiem nang khi, can xae djnh md hinh ddi tuong chua va danh gia tru lugng cho tung cau tao then vong trong mdi be. Oe cd birc tranh tdng quat ve su phan bd tru lugng khf, trong dd cd dang ddi tugng chira nao va khu vue nao cua be cd trien vpng nhat, eung can dugc nghien ciiru.
Ben canh dd, hai van de quan trong cung dugc de cap den: thur nhat, dd la du an khi Nam Cdn Sdn;
thur hai, van de phat trien cac md khi d vuing bien Oa Na'ng, noi cd ham lugng CO2 va H2S tuong ddi cao.
Cac nghien curu ve tiem nang khi d cac be khac cung dang dugc tien hanh va vi vay chua dugc de cap den trong khudn khd bai bao nay.
OA CHU'A
Dua vao nhirng tai lieu hien cd, cd the xac djnh dugc ba loai da chura trong khu vue la: mdng phong hoa va nirt ne, tram tich hat vun va da cacbonat.
Hoi nghj KHCN 2000 "Nganh Dau khi VietNam tnfdc them theky 21'
1. Da mong phong hoa/nut ne
Trong mdt sd be tram tich, mong granit hay da vdi/ddldmit bi phong hoa/nurt ne la nhtj-ng da chira dau khf vao loai tdt.
2. Da chifa hat vun
Cd the coi cat ket, cd tudi tir Oligoxen den Plioxen, la dang da chira phd bien nhat. Cat ket Oligoxen va Mioxen ha dugc hinh thanh trong mdi trudng delta, fluvi va cd kha nang la dang da chira tdt nhat. Cat ket Mioxen trung- thugng, hinh thanh trong mdi trudng chuyen tiep sang nude sau hon, cung ddng vai trd la dang da chira quan trong. Them vao dd ngudi ta cung da tim thay khf trong cat ket Plioxen d be Sdng Hdng.
3. Da chijfa cacbonat
Trien vgng kha quan cua da chira cacbonat tudi Mioxen trung - thugng da dugc chirng minh nhd mot sd md khi mdi phat hien gan day d cac be Sdng Hdng va Nam Cdn Son. Nhin chung cac da cacbonat nay cd do rong tdt. Ngoai do rdng nguyen sinh giira cac hat, kha nang chira dugc tang len dang ke nhd do rdng thir sinh dang hang hoc do qua trinh cacto hoa va dolomit hoa.
CAC MO HlNH 001 TLfONG CHCfA
Cac tich tu dau khf dugc phat hien d cac be ndi tren cd the nhdm lai thanh cac dang ddi tugng chira khac nhau (Hinh 1). Yeu td co ban cua tat ca cac dang ddi tugng chira la phai cd cac tang set Oligoxen, Mioxen giau vat chat hiru co lam da me va di kem theo dd la he thdng rifting. Qua trinh rifting se hinh thanh cac cau tao (bay) va ngudi lanh sau rifting se tao nen su sut liin can thiet de sinh trudng hydrocacbon tir da me.
1. Dd'i tu'dng chufa da mdng nut ne/phong hoa (Ddi tu'dng 1)
Dang ddi tugng chira trudc Oe Tam nay gdm nhieu loai da chira cd tudi khac nhau. 6 be Sdng Hdng, nhu chiing ta da biet, da cacbonat tudi Pecmi - Devon cd chira chut ft dau khf. 6 be Nam Cdn Son, dd'i tugng chura da mdng cung dugc chirng minh qua thur via cua mdt gieng tren md Oai Hiing. Md Bach Ho vdi cac tang chira granit nurt ne cho den nay van la md dau quan trong nha't d Viet Nam.
2. Ddi tu'dng chifa delta chau thd tudi Oligoxen (Ddi tu'dng 2a)
Dang ddi tugng chira nay cd the phat trien d khu vue Odng Nam be Sdng Hdng. Mot sd bao cao da cd md ta su tdn tai cua cac doi cat cura sdng tudi Oligoxen. Md khf Yacheng ciia Trung Qudc cd the dai dien cho dang ddi tugng chira nay. 6 day da chira Oligoxen trong bay chura dang khdi bam dirt gay bi cat cut tai dinh bdi bat chinh hgp Mioxen trung va dugc nap hydrocacbon tir da me set than Oligoxen nam dudi.
3. Dd'i tu'dng chifa delta chau thd/dam hd tudi Oligoxen (Ddi tUOng 2b)
Dang ddi tugng chira nay dugc phat hien d khu vurc Odng Bac be Sdng Hdng va d Id 12 be Nam Cdn Son. Bay d day thudng cd dang vdm ke thira tren nhung khdi nang mdng va chiu mirc do nen ep khac nhau giu'a dinh va canh. Co che chan do set phan tan doc mat trugt dirt gay hay do Idp set bj djch chuyen thanh ddi dien vdi Idp cat tao nen. Oa me la cac Idp set bdt dam hd tudi Oligoxen.
4. Ddi tu'dng chifa hat vun IVIioxen ha (Ddi tu'dng 3a)
Odi tugng chura hat vun Mioxen ha dugc tim thay d cac be Nam Cdn Son va Ma Lai - Thd Chu. Cac md quan trpng dugc phat hien cho den nay la Oai Hiing d be Nam Cdn Son va Bunga Kekwa, Bunga Orkid, Bunga Raia, Bunga Pakma d be Ma Lai - Thd Chu. Oa chira cat ket Mioxen ha dugc hinh thanh trong mdi trudng ven bd, them trong. Dang bay phd bien la khdi bam dirt gay. Oa me la tang set than Oligoxen nam dudi.
152
Hoi nghj KHCN 2000 "Nganh Dau khi Viet Nam trWdc them theky 21'
Hinh 1: Phan loai dd'i tugng chira khf them luc dja Viet Nam
Dang doi tUOng chuia Cacbonat Mioxen trung - thirong
Turbidit Mioxen thLfong Hat vun Mioxen thi/ong Hat vun Mioxen trung
Hat vun Mioxen ha Delta chau thd/dam h6 tudi Oligoxen
Delta chau thd tudi Oligoxen Da mong niirt ne/phong hoa
Ky hieu Be Song Hong Be Nam Con Son
Do! tiWng 4 P - ' • '~ ' -^ . < L i •
Be Ma Lai - Thd Chu
3d ^^mijjjji^giiiimiii
Doi tifcrng 3c
3b ^ ^ ^ ^ ^ ^ ^ H ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ l
Doi tifdng 3a
Doi ti/cmg 2b ,.-.Jft«ya»cr5.-.•>..
2a ^^^^m^^^^^mnin^^^^^^^i
Doi tifcmg 1
Hinh 2: Tdng trQ lugng khf khdng ddng hanh
SONG HONG BASIN NAM CON SON BASIN MALAY-THO CHU BASIN
Triirlu'cfng
Hinh 3: Tru lugng khf theo cac dang ddi tugng chura d be Sdng Hdng
6-"* 0.3«
aPlayl BPlay 2a DPlay 2b QPlay 3b BPlay 3d BPlay 4
Ddi tifcrng 1 Ddi tUtfng 2a Ddi tu'dng 2b Doi tUcrng 3b Odi tifOng 3d Ddi tUdng 4
Phat hien 138.000 151.159
Tiem nang 0.944 20.540 3.566 13.124 5.828 93.136
Du doan Tong
0.642 9.370 0.994 3.613 3.751
1.586 29.910 4.560 16.737 147.579
16.218 260^513
Hoi nghj KHCN 2000 "Nganh Dau khi Viet Nam tnfdc them theky 21'
Hinh 4: Tru lugng khf theo cac dang ddi tugng chira d be Nam Cdn Son
Tru' lU'cfng Phat hien Tiem nang
Dudoan Tong
Odi tu'dng 2a 22.5 13.1 • 17.4 53.0
Dd'i tu'dng 3a 14.9
3.5 3.9 22.3
Ddi tu'dng 3b 33.7 47.7 49.3 130.6
Dd'i tu'dng 3d 55.7 28.5 6.6 90.7
Ddi tu'dng 4 59.5 12.9 20.0 92.4 Hinh 5: Tru" lugng khf theo cac dang dd'i tugng chira d be Ma Lai - Thd Chu
fc|}f!iOu-i':,C IPlay 2a IPlay 3a iPlay 3b
15%
Trur lUdng Phat hien Tiem nang
Dudoan Tong
Dd'i tu'dng 2a 0.000 14.090 16.860 30.950
Ddi tUdng 3a 22.380 20.720 99.620 142.710
Ddi tu'dng 3b 8.830 5.330 14.290 29.080
154
Hoi nghj KHCN 2000 " Nganh Dau khi Viet Nam tnfdc them theky 21'
5. Odi tifong chifa hat vun Mioxen trung (Odi tu'dng 3b)
Dd'i tugng chira hat vun Mioxen trung cd mat d cac be Nam Cdn Son va Ma Lai - Thd Chu. Trong Mioxen trung van tiep tue xay ra qua trinh lang dong cac tram tfeh bien tien, vi vay da chira d day la than cat sudn them va day bien. Cac dang bay dien hinh la khdi bam durt gay va cau tao hinh hoa. Oa chan la bpt set bien tien xen ke. Oa me la set than va cacbonat.
6. Odi ti/cfng chuTa dang turbidit Mioxen tha'dng va Plioxen (Odi tifdng 3d)
Dd'i tugng chura dang turbidit dugc tim thay d Trung tam be Sdng Hdng va Nam Cdn Son. Cac md khf va mdt sd cau tao trien vpng dugc phat hien qua tai lieu dja chan d viing tranh chap giua Viet Nam va Trung Qudc ed the minh chirng ro rang cho su tdn tai cua dang ddi tugng chira turbidit d be Sdng Hdng. Md khf Hai Thaeh va Mdc Tinh d Id 05 - 2 va 05 - 3 la dang ddi tugng chura turbidit dien hinh d be Nam Cdn Son. Da chira cd the du bao la cd dang tam Idp vdi dp lien thdng ngang tdt va dugc nap khf tir da me set Mioxen va Oligoxen.
7. Odi tifdng chifa cacbonat Mioxen (Odi tu'dng 4)
Dang ddi tugng chira nay cd mat d cac be Sdng Hdng va Nam Cdn Son. Nhirng cau tao Idn da dugc chirng minh la cd chura khf lan nhieu COj d viing bien Da Nang va cac md khf Lan Tay, Lan 06 cd the coi la nhifng vi du dien hinh cho ddi tugng chira cacbonat Mioxen. Cac da cacbonat nay dugc hinh thanh trong dieu kien bien ndng. Kha nang chifa cua chung du bao la cue ky tdt.
O A N H GlA VA P H A N BO T R Q Ll/ONG
Phirong phap the tfeh dugc diing de danh gia trO' lugng khf cua tat ea eae eau tao trien vpng, da khoan va chua khoan, cho tUng dang ddi tugng chiira va tirng be. Tdng trur lugng khf eho tat ea eae dang dd'i tugng chira trong pham vi tirng be dugc xac dinh va tdng hgp thanh ket qua trinh bay d cac Hinh 1, 2, 3.
Cung can nhan manh la Dd'i tugng 4 eua be Sdng Hdng, cac Odi tugng 3b, 3d, 4 cua be Nam Cdn Son va Odi tugng 3a eua be Ma Lai - Thd Chu la cac dd'i tugng chira cd then vgng nha't cho tim kiem khf d Viet Nam.
K^T LUAN
Tdng hgp cae sd lieu da trinh bay, tru lugng khf cuia be Sdng Hdng va Nam Cdn Sdn se dat khoang 500BCM va nhu vay, mdi be deu ed the ddng vai trd quan trpng trong viec cung cap khf cho Viet Nam. Thi trudng tieu thu khf tiem nang da dugc Chfnh phu Viet Nam dieu tra, danh gia va du bao la vao nam 2010 se dat ed 15 - 20BCM/nam. Oieu dd cd nghTa la tru lugng khf da va se dugc phat hien hoan toan cd the du cho nhu cau Idn trong vdng hai thap k^ tdi.
Hien tai, Tdng cdng ty Dau khf Viet Nam da xae djnh dude thj trudng khf danh cho mot sd md se dua vao khai thae (4 - 6BCM/nam). Dieu dd cho phep thuc day du an khf Nam Cdn Son de cd the cd dugc ddng khf dau tien vao nam 2000. Su phat then mdt sd md khi bj nhidm ban d vung bien Da N§ng dang dat ra mdt sd thaeh thurc ve edng nghe, bao ve mdi trudng va phat then thi trudng. Neu giai quyet dugc cae van de lien quan den viec tach va xur ly khf CO2 thi cdng nghiep khf d mien Tmng Viet Nam se cd co hdi de phat trien tdt hdn.
TAI LIEU THAM KHAO
1. Lien minh BP/Statoil, 1997, Du an khi Nam Cdn San. - '••
2. Hhom D[i an Pe\roV\e\r\an], 1997, VIJRA. Danh gia tong tru-lugng dau khi d Viet Nam.
3. Pe{roV\e^^\ar(],^99^, Khi tu nhien d Viet Nam: Hien trang va tuang lai.
