* l « «0ir^ 1 1 " ^ • M , Phat hien va khai thac co hieu qua than dan trong da mong granite trade De Tam mo Bach Ho nhiing thanh tun khoa hoc cong nghe va kinh te xa hoi TSKH Phung Dinh Thyc, TS Tran[.]
*lô : ô0ir^- 11 "^-ãM, Phat hien va khai thac co hieu qua than dan da mong granite trade De Tam mo Bach Ho - nhiing tun khoa hoc cong nghe va kinh te xa hoi TSKH Phung Dinh T h y c , TS Tran Ngoc Canh, TS N g u y i n Van IVIinh Tap doan Dau Viet Nam TS Ngo Thu'O'ng San, TS Tran Le Dong, TS Nguyen Huy Quy Hdi Diu Viet Nam TS Hoang Van Quy Xi nghiep Lien doanh Dau Vietsovpetro M& dau Than d i u da mdng granite trudc De Tam n&t ne (da mdng granite nut ne) dugc phat hien l l n dau tien tai gilng BH-6 md Bach Ho nam 1987, dugc kiiang djnh va dua vao kiiai thac tai gilng BH-1 thang nam 1988 Than d i u da mdng md Bach Ho, mdt nhung md idn tren t h i gidi, cd dang khdi, chilu cao Idn, dp rdng nhd, c l u true khdng gian rdng piiuc tap, dac trung thIm ciiua b i t ddng nhIt rIt cao; tr& lugng d i u tai cho ban d i u khoang 600 trieu m3 20 O&U K H i - S O 9/2010 T u than d i u da mdng granite md Bach Ho dygc phat hien va dua vao khai thac, cdng tac tim kilm tham dd d i u khf d Viet Nam dugc day manti va thu dugc nh&ng k i t qua to idn O i n nay, sau ban 20 nam t i i n hanh tim kilm tham d i u khf, d Viet Nam da phat hien them 19 than d i u da mdng granite, vdi tr& lugng d i u tai chd ban d i u khoa'ng 1,2 ty m^ Viec phat hien va dua vao khai thac co hieu qua than d i u mdng granite md Bach Ho va cac md khac d Viet Nam da dat dugc nh&ng tyu to lan va dac biet x u l t sac v i khoa hpc cdng nghe va kinh t l xa hdi ^m -f^-^'Ti » KJ^i I m^'^y ãằ ^*t!3 %M -T ô ằ I 1% i Thanh tiru thij nhIt: Viec phat hien than ddu da mong granite ni>t ne mo Bach Ho & Viet Nam da lam thay doi quan diem tim kiem tham dau khi, dong gop to lan cho khoa hoc dja chat dau Viet Nam va the gi6>i Tren t h i gidi, than d i u da mdng da dugc phat hien va dua vao khai thac tu rIt sdm (md Placerita Caynion, Hoa Ky, nam 1899 - 1901), hien dien a mot sd nai nhung khdng nhiiu va tr& lugng khdng Idn (tr& lugng d i u da mdng udc tfnh khoang - 3% tong tr& lugng d i u t h i gidi) Trudc piiat iiien va dua vao khai thac than d i u da mdng granite md Bacii Ho (nam 1988), ngudi ta van cdn nghi ngd v l kha nang tdn tai d i u khf da mdng va cho rang sy tdn tai d i u da mdng ft cd y nghTa khoa hpc ngoai igi ich nhd v l kinh t l Theo quan diim truyin thong, mdt than d i u dugc hinh c I n cd: Ngudn sinh, t i n g ch&a (vdi dp rdng thudng idn han 8%, dp t h I m lan ban ImD) va t i n g chin Vdi d i i u kien nhu vay, da mdng khd cd t h i la mot than d i u , vi v i ban c h i t da mdng granite la da xam nhap chat xft, dp ring va dp thIm nguyen sinh h l u nhu khdng dang ke (neu tfnh ca dp ring th& sinh, thi dp ring tong cung khdng qua %), cdn dp thIm thay doi khoang rIt Idn (t& d i n 20 Darcy, dp t h I m gi&a bat h l u nhu bang 0); ngoai ra, t i n g chan tren cac than d i u mdng thudng khong ro rang, cho cd, chd khdng Trong thyc t l , khdi da mdng nam lot dudi be tram tich De Tam la cac da xam nhap macma khong phai la doi tugng dugc quan tam vl da mdng gdm cac loai da nhu da biln chat va da dugc tao bdi nham thach dugc hiiu la nh&ng loai da ma dd khdng tdn tai dp rdng va dp thIm ty nhien hoac cd ban chit cung gidn, khdng rdng, khong thIm va theo hpc thuylt h&u ca, d i u khdng t h i sinh va ch&a cac da macma cd ngudn gdc sau vd trai dit Tren t h i gidi, d i n cudi t h i ky XX phat hien d i u da mdng d i u dugc xem la khdng h&u fch va khdng dugc quan tam O Viet Nam, trudc Xi nghiep Lien doanh (XNLD) Vietsovpetro phat hien d i u da mdng cung vay Nam 1974, khoan gilng BH-1X d c l u tao Bach Ho, Cdng ty iVlobil chi tap trung tim d i u d t i n g t r i m tfch Miocen tudi De Tam Cung nhu Mobil, trudc 1975, cac cdng ty d i u nude ngoai khac chT tap trung vao cac doi tygng la t i n g ch&a Oligocen va Miocen cdn Idp vd phong hda tren mat mdng dygc xem la hinh d i i u kien luc dja nen khdng phai la muc tieu tim k i l m tham dd d i u khf Ngay viec thu dygc ddng d i u t& than d i u mdng granite md Bach Ho ban d i u cung gay tranh luan bdi nd la mot "hien tugng la", h i l m gap tham dd d i u tren t h i giai Gilng khoan BH-1 dugc coi la gilng khoan dau D£U KHi 9/2010 21 tien d Viet Nam cd nhiem vu khoan tham dd d i u da mdng Gilng khoan BH-1 dat tai vdm trung tam md Bach Ho, d y g c khoan 26/6/1985, gap ndc mdng tai chilu sau 3105m, k i t thuc khoan 21/1/1986 tai chiiu sau 3178m (md vao da mdng 73m) Trong qua trinh khoan md via lap phong hda da mdng granite bj m l t dung djch toan p h l n , dygc x y ly bang bam ep vd t r i u trdn vdi dung djch khoan Tuy nhien tb& via tang mdng khoang 3161 - 3103m khdng nhan dugc ddng Gilng khoan BH-6 dugc XNLD Vietsovpetro khoan 16/8/1986 va k i t thuc 05/5/1987 tai chiiu sau 3533m Gilng khoan gap mdng tai chilu sau 3510m, md vao mdng 23m Khi th& via d phln day gilng da nhan dugc ddng d i u luu lugng 477m3/ngd Mac du cdn cd nghi ngd nhyng gilng BH-6 dygc coi la gilng khoan dau tien phat hien than d i u da mdng trydc De Tam Ngay 6/9/1988, quay lai khoan va th& iai phln mdng cua gilng BH-1 da nhan dygc ddng d i u cdng nghiep tu phun vdi luu lugng tren 1000m3/ngd G i l n g dugc dua vao khai thac lien tuc cho d i n K i t qua da md mot thdi ky mdi cho XNLD Vietsovpetro cung nhu nganh D i u khf Viet Nam O Viet Nam, sau than dau mong Bach Ho, da cd them 19 phat hien diu da mdng granite nwt ne (Bang 1) V&i nhirng cdng dd, quan diim vi tim kiim tham dd diu da mdng da thay doi: Da mdng granite khdng nhirng cd thi la mdt than diu, ma cdn cd thi la mdt than diu l&n va twang doi phd biin 2 DAU K H i - 9/2010 Bang Cac phat hien diu da mong granite a Viet Nam STT re/7 p/ia( Wen ^ ^ ^ ^ ^^ Gieng phat hien Bach Ho Dong Bac Rong Dong Rong Rang Dong Hong Ngoc Phuang Dong Dong Nam Rong Su T u Den 10 11 Ca NgCf Vang Su T u Trang 12 13 Nam Rong Doi Moi 14 BH-6 R-3 R-11 RD-1X RB-2X PD-1X Nam phat 1987 1989 1993 1994 1995 1995 R-14 1995 SD-1X SV-1X 2000 2001 CNV-1X STT-1X 2002 2003 DIVl-IX SN-1X 2004 Su Ti> Nau Nam Trung Tam Rong Hai Su Den R-15 HSD-1X 2006 2007 HX-1X TL-2X 2008 DH-10X BH-19 2008 2009 Su T u Vang 15 16 17 Ho Xam Nam Thang Long 18 19 Dai Hung Dong B i c Bach Ho Ddng thdi vdi viec thay doi quan d i l m v l ddi tugng, muc tieu tim kilm tham dd d i u khf, cac quan d i l m mdi v i qua trinh di chuyen, tfch tu va hinh than d i u da mdng cung dugc nghien cuu va phat trien Thyc t l tham dd, khai thac d i u khf da mdng granite cho thIy, khai niem "than d i u da mdng granite n&t ne" la mot khai niem cd qua trinh phat trien Ban d i u , dugc phat hien d gilng BH-1, than dau mdng dugc gpi la than d i u cd dang "vd phong hda" Sau dd, d i u dugc tim thIy nam sau khdi da mdng, than d i u dygc gpi la "than d i u mdng granite tuai" Hien chung dygc gpi la than d i u mdng granite n&t ne Thdi gian g i n day, Viet Nam da to ch&c cdng nhiiu hdi nghj qudc t l chuyen nganh v l tham dd khai thac d i u khf da mong vdi hang tram chuyen gia qudc t l tham gia Nhiiu nydc da hii^^ 2005 2008 mdi chuyen gia Viet Nam ty van ve than d i u da mdng Cd nydc da lap Oy ban qudc gia nghien c&u t i l m nang d i u da mdng Tdm lai, viec phat hien va dya vao khai thac cd hieu qua cac than d i u da mdng granite n&t ne d Viet Nam da khang djnh da mdng la mdt loai than d i u mdi (than d i u phi truyin thdng hoac khdng binh thudng) cd t i l m nang Ddng thdi vdi viec thay doi quan d i l m v i ddi tugng va muc tieu tim k i l m tham dd d i u khf, cac quan d i l m v i ca c h i hinh than d i u (sinh, ch&a, chin) da mong cung dugc phat triln Thanh tyu thu- 2: Khai thac CO hieu qua cac than dau da mong granite niFt ne mo Bach Ho va cac mo khac & Viet Nam da sang tao, hinh va khang djnh to ho-p cac giai phap cong nghe mo-i de khai thac mot loai than dau rn&\ phi truyin thong PETRat;'iK?t)^5 Thdng thudng, than d i u truyin thong cd mdt so dac trung thuy ddng Iyc chu y l u sau: it w ^ • ^ + Than d i u dang via vdi dp ring: > 8%, dp thIm: > ImD; d: + C h i dp thuy ddng iyc: Dang nhiet; + Ddng chay: Ddng hudng tam theo phuang ngang Trong do, than dau mong co nhCi'ng dac tru'ng thuy dong ILFC nhu' + Than d i u dang khoi, chiiu cao t& vai tram met tai g i n 2000m; + Dp rdng: 1-4%; dp thIm: - 20D; + Dac trung cua d i u via thay doi theo chilu sau; + C h i dp thuy ddng Iyc: B i t dang nhiet; + Md hinh ddng chay: Ddng hudng tam theo binh cau va/hoac thing d&ng Trong qua trinh khai thac than d i u dac biet (khdng binh thudng) nhu vay, cac giai phap cdng nghe mdi d i n d i n dugc sang tao, phat triln va khang djnh Thf du, than d i u mdng md Bach Ho: Ban d i u , theo S a khai thac thu' cong nghiep than dau mong granite mo Bach Ho nam 1990, phuang an dugc d i x u l t la phuang an khai thac d c h i dp giam ap vdi he thing gilng diem, he so thu hdi d i u cuoi cung dat khoang 17% vdi tong san lugng d i u khai thac dy bao khoang 26 trieu m3 S a cong nghe khai thac va xay dirng mo (Sa cong nghe) chinh thirc dau tien du'ac hoan va phe duyet nam 1993 Theo Sa dd nay, than d i u mdng dygc thiit k l bam ep nyac vao p h l n day va phat trien mu khf d p h l n dinh va se k i t thuc khai thac ranh gidi d i u - khf va ranh gidi nydc - d i u nhan tao gap d chilu sau -3450m, he so thu hoi dau cuoi cung (vao nam 2015) co the dat 22,3% (Hinh 1) © f T Hinh He thong khai thac thw hai Ghi chu: 1- Dai mu dw phong; 2- Dai khai thac; 3- Dai bam ep Than dau mong du'ac bat dau b a m ep nu'ac tip thang nam 1993 Vao cuoi nam 1994, ap s u i t via d dinh mdng chi cdn cao ban ap s u i t bao hda khoang 20at., d i tranh giam san lygng d i u cac gilng d dinh bj ngap khf va tranh phai d i u ty khoan them gilng mdi, than d i u da dygc khai thac vdi yeu c l u "khdng de ap suit via (d dinh) giam xudng thap ban ap s u i t bao hda" (Van kien Ky hpp Hdi dong XVII XNLD Vietsovpetro) Sau dd, vao cudi nam 1995, bam ep nydc dygc yeu c l u : "ap s u i t via tai dinh mdng c I n phai (duy tri) cao han ap s u i t bao hda khoang lOat." Trong S a cong nghe khai thac va xay dirng mo nam 1998, bam ep nydc tri ap s u i t via mdng n&t ne md Bach Ho dygc thiit k l d l tao ap Iyc nhan tao vdi he sd bu khai thac bang bam ep nydc blng 100%, dam bao on djnh ap s u i t via d m&c cao han ap s u i t bao hda 10 - 12at cho khdi trung tam, cac khoi khac khai thac theo c h i dp dan hdi suy thoai cd gi& ap s u i t via t&ng p h l n C h i dp bam ep nhy vay cung vdi he thong bam ep nydc vao p h l n day than d i u (d chiiu sau sau han 3900m) (Hinh 2) da gdp phln gia tang he so thu hdi dau cudi cung len tdi 37,6%, cao ban 2,2 l l n so vdi phyang an khai thac b l n g nang lygng ty nhien va bang 1,7 lan so vdi phyang an khai thac cd mu thy sinh DAU K H i - 9/2010 prs, H^ ' 1' / \ Ngoai ra, de giai quyit sy khac biet r I t Idn v l c l u true va cac dac trung thuy ddng Iyc cua than diu mdng so vdi than d i u binh thudng, nhiiu giai phap cdng nghe mdi cung dugc sang tao nhu: •• r Jt^ \ \ \^ T \ _ Gieng bam ep mo thing aCrng hoac a ngang vao mong Gidng khai thac ma thing dupng hoac a ngang vao mong Hinh He thong khai thac thw ba Ghi chu: 1- Dai khai thac; 2- Dai bam ep Trong qua trinh khai thac, nhan thIy ap s u i t bao hda cua d i u via d phln dinh mdng giam d i n theo san lygng khai thac cdng ddn nen bam ep nydc cung da dygc d i i u chfnh, tdi yu hda kjp thai d l mot mat v l n giy ap suit via d dinh Idn ban ap s u i t bao hda khoang lOat, mat khac cd t h i tan dung tdi da nang lygng dan hdi cua than d i u de gia tang thu hdi d i u (Hinh 3) Giai phap chuyin ty md hinh ddi (Sa cdng nghe 1993) sang md hinh ddi (Sa cdng nghe 1998) cung vdi viec d i l u chinh bam ep theo c h i dp bu g i n du va mot sd giai phap khac nhy gia tang mat dp gilng khoan, khoan c I t than hai, d i l u chinh, dan phang mat Ranh gidi nydc dau nhan tao, d i l u chinh lyu lygng khai thac, bam ep d t&ng gilng, t&ng khu vyc da lam cho he s6 thu hoi dau tang len den 40,2% (Sa cong nghe 2003) va tai 43,2% (Sa dd cong nghe 2008) + De nghien c&u dac trung t h I m ch&a va tfnh toan tr& lugng cua than d i u da mdng, phln m I m BASROC dugc d l xult va &ng dung cdng; + Ca s d d i d i l u chinb/kilm soat trang thai nang lugng cua than d i u mdng la ap s u i t via d dinh (khdng phai ap s u i t via trung binh nhu d than dau binh thudng) va d y g c tri d m&c x l p xi ap s u i t bao hda (d than d i u binh thydng ap s u i t via trung binh cd t h i t h I p han ap s u i t bao hda - % ) ; + Nhjp dp khai thac than dau va lyu lygng gilng khai thac/bam ep dygc tri d m&c hgp ly, de giam thilu hien tygng by-pass d i u tfnh b i t ddng nhIt cao cua dac tryng t h I m ch&a; + He t h i n g thiit bj cdng nghe dugc phat triln theo sa dd tap trung k i t hgp sa dd phan tan mang tfnh chpn Ipc, nham ban c h i tfnh b i t ddng nhIt cua dac trung t h I m ch&a cua than d i u (Hinh 4) Hinh Dong thai nang Iwang than dau mdng trung tam mo Bach Ho 24 DikU KHi-S6 9/2010 + Cac chi sd cong nghe dygc d i l u chinh theo dong thai cua p h l n nguyen ban cua he thong (la d i u via) ch& khdng dua vao dong thai cua p h l n ngoai lai cua he nhu d than d i u t r u y i n thdng (nurac bam ep) cua ca nudc, bo sung cho d i t nudc mdt nguon t i l m nang dau khf mdi (1,2 ty m^ d i u tai chd), tao ddng iyc thuc day cdng tac hm kilm tham dd, khai thac d i u khf d Viet Nam V l kinh t i xa hdi, viec phat hien va dua vao khai thac cd hieu qua cac than d i u da mdng granite n&t ne da: + Tao t i i n d l phat triin nganh D i u khf hoan chinh t& khau d i u d i n khau cudi, bao gdm hm kilm tham dd, khai thac, van chuyen, thu gom x u ly, c h i biln, nghien c&u khoa hpc, phat triin djch vu khoan khai thac, xay lap, thiit k l , c h i tao + Dua Viet Nam vao danh sach cac nudc san xuat va x u l t khIu d i u khu vyc vdi san lugng khai thac d i u khoang - trieu m3/nam; t& nam 1991 vdi san lugng x u l t khau 4,6 trieu m3/nam, l l n dau tien nudc ta da ty can ddi cung c l u x u l t nhap khau xang d i u (Hinh 5) Hinh He thong cong nghe thu gom, xw ly, van chuyen dau mo Bach Ho To hgp cac giai phap cdng nghe tren day t i l p tuc dygc hoan thien, khang djnh va &ng dung qua trinh khai thac cac than d i u mdng granite n&t ne khac d Viet Nam nhy d cac md Rdng, Rang Dong, Phyang Ddng, Sy Ty Den, Ca Ng& Vang, Sy T y Vang Thanh tiru thir 3: Viec phat hien va khai thac cong cac than dau da mong granite nirt ne trirac De Tam them luc dja Viet Nam da mang lai hieu qua kinh te xa hoi to lan T& cd phat hien d i u da mdng granite md Bach Ho va t i l p theo dd la cac than d i u da mdng d cac md khac, d i u tu nudc ngoai ITnh vuc tham dd, khai thac dau khf dugc d l y manh va dat dugc k i t qua rIt to Idn T& 1987 d i n nay, 77 hgp dong d i u khf da dugc ky kit, 66 53 hgp ddng dang cdn bieu iyc Tong dau tu cho cac boat ddng tham dd khai thac d i u khf da len tai tren 13 ty USD Dong thdi vdi viec lien tuc tim cac than d i u mdi da mdng, tr& lugng dau khf tai c h i cua cac than dau da mdng khong ngung gia tang va chilm mot ty trpng dang k l can ddi tr& lugng + Mang lai nguon thu to Idn cho d i t nudc: Tong doanh thu ban d i u la 74 ty USD, dd thu t& d i u mdng la 60 ty, thu nhap da gdp p h l n quan trpng cho n i n kinh t l Viet Nam (Hinh 6); + Gdp phln dam bao an ninh luang thyc: Tren quy md cdng nghiep, t& nam 1995, khf ddng hanh (chu y l u t& than d i u mdng) dygc s& dung d l san x u l t dam Ure (750.000 tin/nam), dam bao khoang 30% nhu c l u phan bdn cho san x u l t ndng nghiep cua ca nude + Gdp p h l n bao dam an ninh nang lygng: T& nam 1996 khf d i n g hanh t& be C&u Long (ma chu y l u la khf t u cac than d i u mdng) da dugc dua v l bd de san x u l t dien vdi san lugng dien hang nam khoang 15 - 17% san lugng dien toan qudc, gdp p h l n dya san lygng dien san x u l t t& thien nhien ndi Chung c h i l m tdi 42 - 45% san lygng dien toan quoc t y nam 2003 (Hinh 7) + Trong nh&ng nam g i n day doanh thu t y x u l t khau d i u thd thydng c h i l m 15 - 16% GDP va khoang 15 - 20% kim ngach x u l t k h I u cua ca nydc Thanh qua da tao d i i u kien on djnh va phat t r i l n kinh t i xa hdi cua d i t n y d c mot thdi gian dai, dac biet la giai doan 1980 - 1990 d l y khd khan cua dat nydc D £ U K H i - 9/2010 25 • / ^ \ Idn va tuang doi b i i n Va nhu vay, da tim va khang dinh mot loai than d i u mdi cdng nghiep d i u t h i gidi Thanh tyu dd da lam thay doi quan diem tim kilm tham dd, khai thac d i u khf da mdng d Viet Nam, khu vyc va tren t h i gidi, gdp p h l n quan trpng cho khoa hpc d i u t h i giai laas :tt7 i%s ^xt 1990 ' « : -.i^ ii/a :94> -.n^ I K :3fn =>« I M JOCO ico: i m j JCKU IQM JQOS JC