Tuygn tap bao cao Hoi nghj KHCN "30 nam Phu khi Viet Nam Cff hoi mdi, thach thuc mdi" 575 DA SINH VA HYDROCARBON LONG 6 BE NAM CON SON Vo Thi Hai Quan Viin Ddu Khi TOM TAT Bi Nam Cdn Son v&i dien tich[.]
Tuygn tap bao cao Hoi nghj KHCN "30 nam Phu Viet Nam: Cff hoi mdi, thach thuc mdi" 575 DA SINH VA HYDROCARBON LONG BE NAM CON SON Vo Thi Hai Quan Viin Ddu Khi TOM TAT Bi Nam Cdn Son v&i dien tich khodng 100.000km ndm ngodi khoi miin Nam Vid Nam, nhiiu ndm qua la mdt nhirng be da phdt hiin dugc ddu vd cd gid tri thuong mgi v&i nhiiu hogt ddng thdm dd vd khai thac Chinh vl vdy, viec nghien ciru vi cdc sdn phdm ddu vd bdn chdt ngudn vdt lieu sinh ban ddu phgm vi bi da ludn hdp ddn cdc nhd dia chdt ndi chung vd cdc nhd dia hda ndi riing Dd sinh & bi Nam Cdn Son chii yiu dugc tim thdy & phdn day cua Miocen giua, trdm tich Miocen du&i vd Oligocen Cdc da sinh rdt gidu vi lugng vdt chdt huTi co; cho thdy tiim ndng sinh ddu vd tdt (mgnh) Chiing tap trung chu yiu & phia Ddng vd khu vuc trung tdm cua bi tu d&i sinh ddu mgnh din d&i sinh cua cdc kerogen logi III vd logi II, chung chu yiu dugc hinh thdnh tu ngudn vdt lieu ban ddu la thuc vdt bgc cao, tdo vd vi khudn, duge luu giu vd phdn huy diiu kiin cd lugng oxy tir cao din trung binh ciia vung trdm tich chdu thd - bdi bdi cua sdng, ddm hd vd viing ven b& Vdt chdt hiru CO ciia cdc logi dd sinh ndy da dgt din pha chinh sinh ddu Hydrocarbon long & bi Nam Cdn San bao gdm: ddu thd, ddu nhe vd condensat, chii yen dugc sinh tu vdt lieu ban ddu la thuc vdt bgc cao vd tdo, dugc trdm tich mdi tru&ng tam giac chdu, bdi bdi cua sdng vd ddm hd Dua vdo cdc dge diem dia hda khdc vi ngudn vdt lieu ban ddu chiing dugc chia thdnh ba logi: • Ddu dam hd dugc sinh tir vgt chat huv co cua thuc vgt bgc cao, cd ty tir trung binh din cao, hdm lugng sdp cao, hdm lugng luu huynh thdp v&i su ddng gdp phd biin cua thdnh phdn nhua vd hdm lugng thdp cua sterane v&i su chiim ITnh cua C29 sterane • Ddu dugc sinh tir da me ddm hd cd ngudn gdc tir tdo nu&c ngot Ddu logi ndy ndi chung cd ty trung binh, hdm lugng sdp cao, hdm lugng luu huynh thdp vd thu&ng cd ndng cao eiia C30-4 methyl sterane • Ddu hdn hgp dugc sinh tir su trdn ldn cua hai logi vgt chdt him co tir da sinh luc dia vd dam hd MO DAU Bai viet tac gia tap trung nghien ciru vao cac trim tich tu6i Oligocen vdi chilu day khoang 100 - 500m, Miocen dudi vdi chilu day khoang 100 - 1000m va diu tai mgt s6 gieng khoan Da sinh d bl Nam C6n Son g6m cac tudng thach hoc nhu: 576 Da sinh va Hydrocarbon long ff bg Nam C o n ^ o j l than, set than va sel ket Theo ket qua long hop cac tai lieu dia hoa dau cung dugc chia cac loai khae dua vao ngu6n goc nhu: dau ngu6n g6c luc dia, dam ho nude ngot va hon hgp Vi vay muc tieu chfnh ciia bai viet la de: (1) Phan loai cac da sinh hydrocarbon d bl Nam C6n Son; (2) Phan loai dau va tim m6i quan he dau lh6 - da sinh LICH SLT PHAT TRIEN DIA CHAT Nam C6n San la be tram lich De tam ldn c6 tiem nang dau cao, dugc hinh vo luc dia va c6 cau triic dia chat phirc tap Qua trinh tao be lien quan din kit qua va cham ciia ba mang ldn: mang Au - A, mang An - Uc va mang Thai Binh Duong Trong mang Au - A dugc xem la binh 6n nhat, mang An - Uc chuyen dgng vl phia Tay BIC, mang Thai Binh Duong chuyen dgng ve phia Tay va chiic xu6ng dudi cac mang khae Lich sii' dia chat be Nam C6n Son dugc chia lam ba giai doan chfnh: Giai doan Paleogen La thdi ky tao rift, sut lim xay nhanh va manh, tram tfeh lap day at Giai doan loan bo them luc dia Sunda co be Nam C6n Son bude qua thdi ky san bang kien tao tii' giua Olfgocen den cu6f Oligocen Do anh hudng ciia pha gian day bien D6ng, toan bo be chiu su chi ph6i ciia trudng ung suat tach gian tao rift Hoat dong kien tao tach gian Iheo cac he dul gay phat sinh tii' mong la dgng luc lao nen cac dia hao ban dau ciia be keo dai theo hirdng D6ng - Tay, dugc lap day cac tao tram tich vun tudng dam h6 luc dia chuyen dan sang cac tudng chau tho, viing vinh, be day dat tdi hang nghin met Tuy nhien, d6ng thdi vdi van dong cang sut tao dia hao cue bo, cac kh6i mong trudc Kainozoi ke can dugc nang len kieu nhung dia liiy nho ma tren ve sau phat trien cac cau tao ke thii'a tram Ifch Ire han CO y nghia dau khf quan trong, tieu bieu la ddi nang Mang Cau Nhu vay, thdf ky Paleogen la giai doan bat dau hinh be, tao nen nhtrng dia hao va ban dia hao dugc ngan bdi nhung kh6i nh6 cua mong bi kh6ng che va gidi han bdi cac diit gay sau Vi vay, cac lao Paleogen (Oligocen) rat mong ve phfa Tay va day tdi hang nghin met o' phfa D6ng Giai doan Miocen a Giai doan Miocen s&m Sang dau Miocen loan vimg bi thap dan, bien lien tren loan be lir D6ng sang Tay, cac tao luc nguyen tudng bien ven bd va bien n6ng dugc b6i dap, cac ihanh lao dugc xip vao he ting Dira Day la giai doan oan vong mo rong be va pham vi be dau xuat hien mot pha tach gian nhe theo hudng Tay Tay Bae Dong Dong Nam, nhung nhin chung pha kfen sinh kh6ng manh, khong keo dai va on dinh vao diu Miocen giua Su sut lim oIn vong da mo rgng cac viing lich tu bao iriim len cac 16 04, 10, 11,21, v.v Tuygn tap bao cao Hoi nghj KHCN "30 nam Phu Viet Nam: Cff hoi mdi, thach thuc mdi" 577 b Giai dogn Miocen giua - mudn Giai doan pham vi be xuat hien dau cac bieu hien ciia chuyen dong nang - nghich dao NhOng bilu hien c6 le c6 tir giua Miocen giiJa dieu co the thiy bdi gian doan trim tich d phan ria be va hinh mgt s6 cau tao dia phuang Do cac chuyin dong nghich dao, dac biet la d phfa Bae be ma kh6i nang Mang Cau va C6n Son keo dai ve phia D6ng, D6ng Bae (khu vuc 16 04) ngan each ban triing Bae vdi trting trung tam Mot s6 cau tao d 16 11 ciing dugc hinh giai doan Van dong cang manh (vao cu6i Miocen gitra) tao nen mat bat chinh hgp goc giua Miocen giiia vdi Miocen sdm, tren dinh mgt s6 cau tao xay boc mon xam thuc manh Dau Miocen mugn bien lai tien vao tir hudng D6ng da hinh cac tap tram tich bien tien ke g6i tren mat bao mon cu6i Miocen giiia Sat cu6i Miocen muon, mgt lan nu'a loan the bi nang len, bien liii ve phfa Dong, ket thiic giai doan oan vong md rgng be Cac chuyen dgng kien tao cu6i Miocen mang tinh rong ldn kh6ng chi be Nam C6n Son ma mang tinh khu vuc tren nhieu viing khae cua them luc dia Viet Nam va loan D6ng Nam A c Giai dogn Pliocen - Di tuDay la giai doan bien md - phat trien them luc dia kh6ng chi d be Nam C6n San ma c6n d nhieu be khae loan viing Bien tien at phii ngap cac ddi nang C6n Son, Korat-Natuna, binh d6 cau true be kh6ng mang tinh ke thira ciia giai doan trudc, chiing co khuynh hudng nghieng dan ve phia bien D6ng, cac tao tudng bien dugc lang dgng va dugc xep vao he tang bien D6ng Cung thdi gian cac tap cat xen set dang nem lan m6i trudng bien n6ng - bien sau, c6 chira dau da dugc lang dgng tren mgt so cau tao be (Hinh 1) Hl^itraanglT DIA T£r e S &£ o Ji s e io ' o \ n: ^ I s ; 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