644 Ba sinh va tilm nang Hydrocarbon d Id B thudc bllVlajaN^^TIio^Chu "% a DA SINH VA TIEM NANG HYDROCARBON O LO B THUOC BE MALAY THO CHU Pham Thi Toan Viin Ddu Khi TOM TAT Cdng tdc tim kiim thdm dd d[.]
644 Ba sinh va tilm nang Hydrocarbon d Id B thudc bllVlajaN^^TIio^Chu "% a DA SINH VA TIEM NANG HYDROCARBON O LO B THUOC BE MALAY - THO CHU Pham Thi Toan Viin Ddu Khi TOM TAT Cdng tdc tim kiim thdm dd ddu & thim luc dia Tdy Nam Viet Nam thudc bi Malay - Thd Chu nhiiu ndm qua dugc tiin hdnh b&i Cdng ty Unocal vd Fina Viec lay cdc logi mdu phdn tich la cdc nhd thdu dam trach Cdc bdo cdo dia hda Viin Ddu Khi thuc hiin la tdng hgp tdi lieu phdn tich mdu cho timg giing khoan riing bid theo yen cdu nhd thdu Trong bdi viet ndy, tdc gid sir dung tdi lieu phdn tich dia hoa cho cdc mdu da vd mdu ddu ldng dugc lay tir cdc giing khoan thudc Id B Unocal khoan nhiing ndm 1998 2004 Kit qud nghiin ciru dd xdc dinh dugc sir tdn tgi hai logi dd sinh dge tnmg mat cdt trdm tich Di tam Dd la da sinh ngudn gdc tam giac chdu thd bdi bdi tudi Mioeen giua tren vd da sinh ngudn gdc dam hd tudi Miocen du&i - Oligocen Sdn phdm hydrocarbon long phdt hiin & Id B la ddu nhe/condensat gidu paraffin - naphthene dugc xip la ddu logi D, E cd ngudn gdc tir hai logi da sinh niu tren DAT VAN DE Tir nam 1998 tdi nay, C6ng ty UNOCAL Vietnam (Unocal) da tien hanh khoan hang chuc gieng khoan tham dau d be Tay Nam Viet Nam Cimg thdi gian Vien Dau Khi (VPI) da thuc hien hang ngan chi tieu phan tich dja hda cho cac mau da, condensat (rieng cac mau la rat it kh6ng dai dien, mau nude via kh6ng dugc yeu cau phan tich) Unocal thu thap tir cac gieng khoan tai cac 16 B, 52/97, 48/95, v.v Nhung nghien cim dudi day tac gia trinh bay y kien danh gia ve tiem nang vat chat hiiii CO (VCHC) cua da sinh va m6i quan he nguon goc gitra cac san pham hydrocarbon 16ng vdi da sinh t6n tai mat cat tram tich De tam thuoc 16 B ciing nhu be Malay - T h i Chu Tai lieu dja chan - dja tang cua Unocal da xac djnh cac tram tich tu6i De tam d be Malay - Th6 Chu noi chung va 16 B ndi rieng nhu sau: tram tich Oligocen (tap K), va tram tich Miocen dudi (tap K, J, I, H) co chilu day hang tram tdi hang ngan met chira nhtrng tap set ket day xen ke vdi cat kit va hot kit Trim tich Miocen giira (tap H, F, E) va trim tich Miocen giiia la su xen ke lien tuc cua cac ldp than, set than va set ket vdi nhimg tap cat ket CO mat hau het cac gieng khoan Rieng gieng khoan KQ-IX da khoan tdi mdng trudc De tam d chieu sau dudi 1513m Kit qua nghien cim sinh dja ting cua Vien D I U Khi cho thay trim tich Oligocen c6 chira phirc he bao tir phin hoa thuge ddi Florschuentzln Pl Trilobata, Cicatricosisporites dorogensis, Magratriaties howardii, v.v la nhimg dang thudng dac trung cho m6i trudng 645 Tuyin tap bao cao Hdi nghj KHCN "30 nam DSu Viet Nam: Co hdi mdi, thach thuc mdi" trim tich dim h i tuli Oligocen Cac phirc he bao tir phin hoa neu tren cung co mat Irong trim tich Miocen ciing vdi tao nannofossil nhu: Discoaster deflandres, Dis Kygleri, Hdicosphaera ampliaperta, Dis Hamatus, v.v Su t6n tai mgt phirc he c6 sinh vat dac trung nhu tren chirng t6 trim tich De tam dugc tao d dieu kien dam ho - tam giac chau CO anh hudng ciia m6i trudng bien ven bd Van de dugc quan tam la muc phong phu VCHC cua tram tich De tam cung nhu tiem nang sinh hydrocarbon cua chimg co mot m6i lien he nhu the nao vdi cac tich liiy dau nhe da dugc phat hien cac gieng khoan thuoc 16 B va ca d be tram tich Malay - Th6 Chu Noi dung nghien cim ciia bao cao cho phep giai thich van de vira neu dua tren co sd cac phan tich dja boa cho mgt lugng kha ldn cac mau da va dau nhe Unocal Ihu thap tir cac gieng khoan d 16 B nhu sau: Bang 1: »o lu'cm g mau prian ticn (lia hoa cua cac gieng kiioa n Ten GK Mau da Mau dau 0' lo D KL-IX KL-2X KL-3X KL-4X KQ-IX AQ-IX AQ-3X CV-IX TXT-3X 101 186 38 144 0 152 02 05 03 02 05 03 02 DO GIAU VAT CHAT HlTU CO VA TIEM NANG SINH HYDROCARBON Hon 600 mau da dugc lay tir cac gieng khoan dien tich 16 B tai cac cau tao Kim Long, Kim Quy, Ac Quy, Tra Xanh Tay, v.v da dugc phan tich cac th6ng s6 dja hoa tai phong thi nghiem ciia Vien Dau Khi vdi cac chi tieu TOC, S1, S2, Ro, TSE, GC, v.v Tram tich tuoi Pliocen va Miocen tren g6m cac tap than, set than va set ket carbonate CO be day 800 - 1200m hien dien d tat ca cac gieng khoan thuoc 16 B va ca cac gieng khoan khae ciia be Malay - Th6 Chu Day la tap tram tich c6 phan thach hoc rat dac trung cho cac be tram tich dang chau th6 - dam lay ven bien Cac mau phan tich thuge phan mat cit rit giau VCHC vdi ham lugng TOC tu 50 - 55% (KL-IX), 43 - 46% (KL-3X), 45 55% (KQ-IX) va TOC ~ 50% (TXT-3X) Gia trj S2 cung rit cao hiu hit cac miu, khoang 70 - 80kg/T (KL-IX, 3X), 60kg/T (AQ-IX), 85 - 95kg/T (KQ-IX) va 72,05kg/T (TXT-3X) Tuy nhien, chi s l HI tinh dugc thudng < 200mg/g la dac trung ciia da sinh chira vat chit htru ca giau kerogen loai III co tiem nang sinh la chinh Bang 2: Gia tri trung binh cae thong so dia hoa cua da sinh Miocen - Oligocen d 16 B be Malay - Thi Chu TOC (%) Sl (kg/T) S2 (kg/T) Ro(%) Tmax C ) Miocen tren - Ni 45,53 3,64 74,38 ^ "^ u -4) ^ ' JS ^.ts a >«s a 2; oi OLH : c u d iS c O 'bj o o H o u E 'G a 10%) la bieu hien m6i lien quan tai ngu6n vat lieu sinh tu su phan huy \6p bieu bi ciia cac loai thuc vat bae cao (dau loai D, E), hoae ciing c6 the la su t6ng hgp hydrocarbon tu tao phan huy moi truong nuac ngot (dau loai C) Trong thi dau loai A, B sinh tu vat lieu hiiu CO ngu6n g6c bien lai co ham lugng sap < 10% Bang 3: Gia tri trung binh cac tinh chat hoa ly cua dau nhe/condensat 16 B bg Malay - Th6 Chu Thdng sd Ty C'APl) Luu huynh (%) Sap (%) Asphalthene (%) Vanadium (ppm) Nickel (ppm) C15+ hydrocarbon no (%) Ty so Pr./Phy GK KL-IX 47,37 0,010 14,57 0,39 < 0,003 0,02 99,05 6,04 GK AQ-IX 46,73 0,025 12,10 GKCV-iX 53,34 0,007 11,21 - - - - 98,16 6,17 97,27 6.94 Ghi ehii: (-) la kh6ng co s6 lie u Cae thong s6 dia hoa tu kk qua phan tich GC eho n-alkane tinh dugc ty so pristane (iC9) vai phytane (iC20) va ty s6 (Pr/Phy) duge dung de ehi miic oxy hoa ciia moi truang chon viii vat lieu sinh (theo Didyk et al., 1978) dieu kien giau oxy cac san pham 653 Tuygn tap bao cao Hoi nghj KHCN "30 nam Phu Viet Nam: Co' hoi mdi, thach thuc mdi" hydrocarbon co xu huang giau phan pristane va nguge lai phytane dugc tao tu su khu phytol a m6i truang ngheo oxy Theo quan diem chung eiia nhieu nha nghien eiiu (Didyk et al., 1978; Ten Haven et al., 1985, 1988; Brassell et al., 1983, v.v ) tu eae loai dau a nhilu hk trhm tieh tren th§ giai thi dau loai A, B, C co ty s6 Pr/Phy < 3; dau loai D E c6 ty s6 Pr/Phy > C) Bang t§t ca cae mau dau duge nghien ciiu a 16 B deu eo ty s6 Pr/Phy rat cao (6,04 - 6,94) va tren Hinh chiing hien dien khu vuc phan b6 eae dau loai D va E Tom lai, nhiJng ket qua nghien cuu tren day co the ghi nhan cac mau dau dugc nghien ciiu tu cac gieng khoan 16 B la loai dau nhe/condensat, dugc xep la dau loai D, E eo lien quan vai vat lieu sinh giau VCHC nguon g6c thuc vat bae cao cua da sinh ch6n viii a dieu kien giau oxy QUAN HE GIUA DA SINH VA DAU LO B Trong phan cae th6ng so biomarkers t6ng hgp tu tai lieu phan tieh GC, GCMS, v.v cho ca cac mau dau va mau da tu cae gieng khoan KL-IX, KQ-IX, AQ-IX duge sii' dung de tim hieu m6i quan he ngu6n g6c giira dau vai ngu6n vat lieu sinh Cac mau set ket tu6i Miocen duai a 3080 - 3440m (KL-IX) eo ham lugng C15+ hydrocarbon no a miic thap (34,62 - 46,43%) va ty s6 giua cae hgp phan hydrocarbon (no/thom) cung tuong d6i th§p (1,80 - 2,17) so vai hai miu dhu DST#2, DST#3 (KL-IX) CO cac gia tri tuang iing la 98,91 - 99,18% va 135,49 - 241,90 Dieu chiing to vat lieu sinh la loai giau faraffin-naphthene, nhien VCHC sinh cac dau nhe c6 truang nhiet cao hon nhieu so vai VCHC ciia da sinh dugc nghien eiiu bao cao (Bang 4) Bang 4: Gia trj trung binh cac thong s6 biomarkers cua dau va da sinh 16 B bi Malay - Th6 Chu Thdng sd GK CV-IX GK KL-IX GKAQ- IX Dd sinh N/' DST#2 vd TST#1; TST#3 355,59 501,50 854,96 616,37 3447,15 TST#5 173,87 Bl/8p(H)-Drimane/ - 915,14 B2/8P(H)-Homodrimane/ - 3285,50 H15/18a(H)-Oleanane/ - 52,53 53,11 10,24 14,11 H19/Bicardinane/hopanes - 120,02 153,11 8,97 C15+HCno(%) 40,53 99,05 98,82 97,50 94,35 Ty s6 HC no/thom 1,98 288,69 83,75 78,00 19.49 Ty so Pr/Phy 6,56 6,04 4,28 8,05 11,88 Ghi chii: (-) khdng cd sd lieu (HC) - hydrocarbon Cung tu tai lieu phan tich sic ky (GC) nhan thiy co su tucmg d6ng vk gia tri ciia ty so Pr/Phy » tat ca cac miu diu va cac miu da sinh (tu6i Miocen gilng 654 Da sinh va tigm nang Hydrocarbon d Id B thudc bl Malayj^Thd^jiu^ khoan KL-IX) Dilu phan nao phan anh mot mli lien quan giiia vat lieu sinh dau vai da sinh (co thi) dugc chon viii ciing m6i truong giau oxy va cung la nai ton tai mot phire he VCHC nguon glc luc dia chiem uu the hon Tai lieu phan tich sic ky khoi phi (GCMS) cho phep xac dinh su hien dien dau vet co sinh vat clu tnic phan tu hydrocarbon ciia dau a cac gieng khoan KL-IX, AQ-IX VA CV-IX Truae hit la ho cac clu tir Bicyclic Sequiterpanes rat de nhan bilt tren phan manh m/z 123 va chiing eo mat hiu hit cac loai dau tho Cac Bicyclic Sequiterpanes gom Tri- va Pentacyclie terpanoid co nguIn g6c tir thuc vat bae cao la chinh va it hon la tir hopanoid qua trinh diagenesis (Alexander va n.n.k., 1984) Ty s6 n6ng hai cau tir 8p(H)-Drimane va 8p(H)-Homodrimane so vai C30 Hopanes (Bl = 3/G va B2 = 7/G) rit cao tit ca cac miu diu vai Bl = 173,87 - 915,14 va B2 = 501,50 - 3447,15 (Bang 4) da chimg to cac dau chu ylu dugc sinh tir ngu6n da sinh giau cac vat lieu thuc vat bae cao Mot thong s6 biomarker quan khae can quan tam la nong cua 18a(H)Oleanane diu co ky hieu la pic 01 tren phan manh m/z 191 va dugc nhan biet tir quan he cua no vai C30 Hopanes (H15 = 01/G) Oleanane dugc xac dinh co nguon goc tir thuc vat bae cao cay co hoa hat kin (angiosperm) rat phong phii tram tich tu6i tir Creta muon tai hien (Goodwin N.S va Mann A.L., 1986) Trong Bang va Hinh 3, oleanane co ning cao tai H15 == 53,11 dau TST#1 (AQ-IX) va H15 = 52,53 diu DST#2, (KL-IX) Trong diu TST#5 (CV-IX) va diu TST#3 (AQ-IX) co gia tri HI5 la 14,11 va 10,24 Nhiing s6 lieu ghi nhan rang duong nhu cac dau dugc tao tir vat lieu sinh h6n hgp bat ngu6n tir hai loai da sinh khae (?) That vay, vai n6ng oleanane cao thi ba mau dau neu truac co bieu hien lien quan vai ngu6n VCHC giau kerogen loai III, la loai dugc sinh tir sir phan hiiy thuc vat bae cao Hai mau dau neu sau CO bieu hien dugc sinh tir nguon VCHC chiia dau vet thirc vat bae cao chi vai mot ty le nho vira phai Nong cao ciia bicardinane ciing la mot dau hieu nhan biet vat lieu sinh co nguon goc tir thuc vat bae cao vai su hien dien cac pic W, T, R tren phan manh m/z 191, 217, 231 Ty so giiia bicardinane vai C30 hopanes (HI9 = W -i- T + R/G) rit cao cac dau DST#2, (KL-IX) va TST#1 (AQ-IX) vai H19 - 120,02 - 153,11 cho thiy da sinh cac dau chiia phong phu VCHC nguon glc thuc vat bae eao Ben canh do, cac diu TST#3 (AQ-IX) va TST#5 (CV-IX) co gia tri H19 = - 8,97 chimg to ty le VCHC da sinh thap hon nhieu Tom lai, co the cho rang dau nhe/condensat a 16 B la san pham dugc sinh tir VCHC h6n hgp, dau vet vat lieu sinh nguIn glc thuc vat bae cao chiem uu the, de dang nhan thay cac diu DST cua KL-IX va TST#1 cua AQ-IX Cac miu diu khae la bilu hien su pha tron tuong doi giira cac loai vat lieu sinh khae KET LUAN • Trong mat cit trim tich De tam o 16 B bl Malay - Th6 Chu co tin tai hai loai da sinh dau Do la da sinh nguIn glc tam giac chau bai boi ven ba dac trung cho tram tich tuli Miocen giiia - duai eo bl day hang tram tai hang ngan met Thanh phan thach hoc da sinh loai la cac lcrp than, set than rit day xen ke vai set ket mau xam gap a tit ca Tuygn tap bao cao Hgi nghj KHCN "30 nam Phu Viet Nam: Co' hdi mdi, thach thuc mdi" 655 cac gilng da khoan ciia 16 B Day la da sinh rit giau vat chit him ca, co tiem nang rit manh sinh hydrocarbon dang la chinh Tuy nhien, da sinh loai a 16 B hien chua dat tai dai truong nhiet • Da sinh nguon glc dim h i dai dien cho tram tich tu6i Miocen duai va Oligocen phan b6 hau khIp 16 B (ngoai trir khu vuc gieng khoan KQ-IX a phia Tay Nam 16 B) Da sinh g6m cac \dp 'day set ket xam va xam xanh co tiem nang vat chat hiru ca tir ngheo den trung binh va da dat tai nguong truong nhiet a khoang chieu sau 2650m • San pham hydrocarbon long tim thay a 16 B la loai dau nhe/condensat rat sach giau paraffin-naphthene dugc xep la dau loai D, E va dugc sinh tir ngu6n vat chat htm ca h6n hgp Trong do, a khu vuc phia D6ng Bae (cau tao Kim Long va Ac Quy) dau co bieu hien lien quan tai ngu6n kerogen cua vat lieu sinh giau phan thue vat bae cao cay hat kin rat ph6 bien da sinh Miocen giiia - duai da neu tren Cac dau phat hien a khu vuc gieng khoan CV-IX va TST#3 cua AQ-IX thi hien sir pha tron tuong d6i cua nhieu ngu6n vat lieu sinh vai su hien dien tuong d6i it vat chat hiru ca loai III • Dau nhe/condensat a 16 B co truang nhiet rat cao, da sinh dugc nghien ciiu hien a mirc truong thap Vi the, rat co the mat cat da sinh dai truong cao phan b6 a chieu sau duai TD ciia cac gieng khoan 16 B noi rieng va ca be Malay - Th6 Chu noi chung mai chinh la ngu6n cung cap vat lieu sinh cac dau da dugc nghien ciiu bai viet TAI LIEU THAM KHAO Pham Thi Toan, 1998 - 2005 Cdc bdo cdo dia hda cdc giing khoan bi Tdy Nam Vid Nam Luu trii Vien Dau Khi Pham Thi Toan va n.n.k., 2003 Mdt sd kit qud nghiin ciru dd sinh vd ddu thd & bi Ciru Long Pham Thj Toan, 2000 - 2003 Cdc bdo cdo dia hda cdc giing khoan mo Dgi Hung Luu tru Vien Dau Khi Do Bat va n.n.k., 2003 Dinh danh vd lien kit dia tdng trdm tich Di tam them luc dia Tdy Nam VietNam Jennifer A Miles, 1989 Illustrated glossarry of petroleum geochemistry BP Research, 1990 Geochemistry for exploration and production - Notes I and U Barwise A J.G., \9Z4 Composition of oil: An innitial investigation Douglas W Waples, Tsutomu Machihara Biomarkers methods in exploration Series No for geologists AAPG ... nhe/condensates cf Id B be Ma lal-Tho chu a, b: Bieu hien giau dau vet thu''c vat vat lieu smh c: It dau vet thu''c vat bae cao ,^^ Da sinh va tiem nang Hydrocarbon d Id B thudc b g l V I a j a y j... tich cacbonat) X B Bien (tram tich vun silixic) Bien Bae + C Dam ho Trung Quoc - D E A D,E Vung chau tho, ven bien, dam lay Vung chau tho, ven bien dam lay Vinh Suez, Abu Dhabi Indonesia Be Gippland,... chdn) 646 Da sinh va tilm nang Hydrocarbon d lo B thudc bl Malay - Thd Chu Trim tich Miocen giua (tap E, F, H) chua ham lugng than it hon ban phan mat cat Miocen thugng Mau phan tich dja boa dugc