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508 iing dung mang noron nhan tao trong tinh toan do rong tTNG DUNG MANG NORON N H A N TAO TRONG TINH T O A N • • • DO RONG vA DO T H A M CHO CAu TAO V I T N G DONG, THEM LUC DIA PHIA NAM VIET NAM • •[.]
508 iing dung mang noron nhan tao tinh toan rong tTNG DUNG MANG NORON • • NHAN TAO TRONG TINH TOAN • DO RONG vA DO T H A M CHO CAu TAO V I T N G DONG, THEM LUC DIA PHIA NAM VIET NAM • • • Bill Thi Thanh Huyen, Yasuhiro Yamada Toshifumi Matsuoka Dai hoc Tdng hgp Kyoto H6 Trgng Long, Keisuke Ushijima Dai hoc Tdng hgp Kyushu TOM T A T Do rdng vd thdm ddng mdt vai trd quan trong viec ddnh gid tiem ndng ddu cua mdt tdng chira Sir phdn bd ciia chiing cd thi dugc kit hgp v&i cdc tham sd khdc viec du dodn cdc dut gdy chinh hay cdc d&i nut ne tuo'ng ung v&i khu vuc cd rdng cao Cdu tgo Virng Ddng ndm be Ciru Long, mdt bi trdm tich & thim luc dia phia Nam Viet Nam vd Id mdt ddi tirgng chinh cho viee thdm dd ddu Trong nghien ciru ndy, chimg tdi da dp dung mgng naron nhdn tgo (viit tdt la ANNs_ Artificial Neural Networks) di tinh todn rdng vd thdm true tiip tu cdc tdi lieu dia vdt ly gieng khoan Di tgo cdc tap mdu hudn luyen cho ANNs, mdt td hgp cdc sd lieu dia vgt ly giing khoan bao gdm rdng neutron, mat khdi, sdng dm P, dien tr& sdu su&n (LLD), dien tr& su&n ndng (LLS) vd diin tr& vi dien cue hdi tu cdu (MSFL) da dugc su dung nhu nhirng tham sd ddu vdo ciia mgng Ddu tien ANNs dugc hudn luyen b&i cdc sd lieu thu thdp dugc tir mdu ldi Mdt vdi md hinh mgng noron da dugc thir nghiem dua tren co s& ciia phep thir vd sai Chiing tdi dd diing thugt todn lan truyen nguge theo khdi di hudn luyen mgng naron rdng nhdn thdy rdng thugt todn lan truyin nhanh la hiiu qud hon tru&ng hgp hudn luyen mgng noron thdm Suphdn bd rdng vd thdm cd thi kit hgp v&i cdc kit qud minh gidi tdi lieu dia chdn di xdc dinh vi tri eiia cdc dut gdy khu vuc nghien ciru ANNs da cho nhung kit qud khd khd quan vi suphdn bd rdng vd thdm v&i tin cdy cao tdc tinh todn nhanh, chinh xdc vd chi phi thdp Nh& nhung ddc tinh nhu vdy, chimg tdi thiet nghi, ANNs nen dugc ung dung rdng rdi hon ngdnh cdng nghiep ddu Viet Nam LOI MO D A U Do r6ng va tham la nhiing th6ng s6 chinh ve dac trung ciia mgt ting chua cung nhu de xac dinh cac dac tinh ciia mgt dong chay dl tii uu hoa viec khai thac mgt mo diu Nhimg du doan tin cay ve rong va thim c6 tinh chit quylt djnh viec danh gia su lich lu Tuygn tap bao cao Hoi nghj KHCN "30 nam Dau Viet Nam: Co' hoi moi, thach thiic moi" 509 hydroeaebon viec phan tich ve sir bien thien ciia dong dau loan be \a khoanh dinh cac tang chan c6 ap suat cao de giam thieu nhimg sir c6 khoan (Hans 2001) Nhieu yeu t6 co lien quan voi r6ng tir cac duong cong dia vat ly gieng khoan nhu: mat do, sieu am, neutron hay cac gia trj dien tro (Schlumberger, 1989) thi tham co quan he vai dien tro va phu thuoc vao r6ng (Wyllie va Rose, 1950) Tuy nhien, viec minh giai cac s6 lieu dia vat ly gieng khoan thong thuong co mgt vai nhugc diem cac s6 lieu bi anh huong boi nhieu yeu t6 khae nhu tinh chat thach hgc ciia he, luu chat cac 16 r6ng, dang hinh hgc ciia cac 16 r6ng, tinh bat d6ng nhat ciia he hoae sir nhiem ban he ANNs da bat dau dugc img dung de giai quyet cac van de ciia dja vat ly tii' cu6i nhirng nam 1980 (Raiche, 1991) va cang dugc sir dung nhieu viec minh giai cac tai lieu dja vat ly Mang noron (NN), cting gi6ng nhu mgt phuong phap xir ly tren may tinh, da cho thay mgt tiem nang rong mo viec nhan biet cac dau hieu ciia cac nhiem vu dja vat ly (El-Qady va Ushijima, 2001) Trong nghien ciru nay, voi nhirng s6 lieu dja vat ly gieng khoan va mau loi ciia cau tao Virng D6ng, chiing t6i da ap dung ANNs de tinh toan r6ng va tham true tiep tir cac tai lieu gieng khoan Cac ket qua thu dugc da dugc d6i sanh voi ket qua tinh toan theo each thong thuong de xet xem giira mang noron va phuang phap tinh binh thuong thi phuang phap nao la hieu qua nhat O phan cu6i ciing ciia bao cao, su ket hgp giira phan b6 r6ng voi cac ket qua minh giai tai lieu dja chan dugc diing de du doan cac dirt gay chinh va cac doi nirt ne VAI NET TONG QUAN VE CAU TAO VlfNG DONG Cau tao Vimg D6ng nam be Cim Long (Hinh 1) them luc dia phia Nam Viet Nam Be tram tich la mgt khu vuc trien vgng nhat cho viec tham va khai thac dau a Viet Nam va dugc hinh ky Kainozoi duoi anh huong ciia sir va cham An - Au va tao su tach gian bien Nam Trung Hoa (Phuong, 1997), va cau tao Vimg Dong nam 16 15-2 cua bl tram tich ciing la mgt d6i lugng can dugc quan tam nghien ciru (Hinh 2) Clu tao Vimg D6ng dugc dac trung boi v6 s6 cac dirt gay nho xuyen cit cac khu vuc nh6 cao cua mong granit nut ne Nhung dirt gay ty le Ion cat qua kh6i mong nh6 cao, chii ylu CO huong D6ng Bae - Tay Nam va D6ng - Tay Hinh dang cau triic dugc cho ring bit nguon tir sir trugt bang tren dirt gay S6ng H6ng va sir mo bien Nam Trung Hoa thai ky Kainozoi (Huyen, 2003) Trong nghien cim nay, minh giai dja chan, chiing toi kh6ng chia nho cac tap trim tich ma chi chia mgt s6 ranh gioi chinh nhu sau: mong (truoc De tam), tap E, tap D, lap C, B1 va cac tap tram tich tre hon la B2 va A Lien ket dja tang voi cac gieng khoan VD-IX, VD-2X khu vuc nghien cim dugc trinh ba\- tren Hinh (dya theo tai lieu ciia TVPC 2000; 2001) Ung dung mang noron nhan tao tinh to^n rdng 510 106»00 108°00 106000 10800 Hinh 1: Vi tri cua cau tao Vimg Dong (dt^a trin tdi lieu cua JVPC, 2001) 108.00E Q 108.02£ -10.04N Hinh 2: Vi tri cua cac mat c^t dia chan du-g-c trinh bay bao cao Hinh 3: Lien ket dia tang voi tai lifu gieng khoan cua 16 15-2 (Theo JVPC, 2000) Tuygn tap bao cao Hoi nghj KHCN "30 nam Phu Viet Nam: Co hoi moi, thach thiic mdi" 5L^ MINH GlAl T A I LIEU DIA V A T LY GIENG KHOAN • • • Do rong ciia dit da co thi xac djnh dua vao cac duong cong dia vat ly gieng khoan nhu sieu am mat do, natron hay dien tro Gia trj cua cac duong cong dja vat ly gieng khoan kh6ng chi phu thuge vao r6ng (tp) ma phu thuoc vao tinh chat thach hgc ciia he, vao chit long cac 16 r6ng va mgt vai truang hgp, no phu thuoc vao dang hinh hgc ciia cau tnic 16 r6ng Vi le do, cac gia trj r6ng chi co the dugc xac dinh chinh xac tir cac duong cong dja vat ly gieng khoan neu nhu cac tham s6 thach hgc cua khung da va chat 16ng tang chua nhu {t„,a, tf, w,,,^, W,„ p,,,^, pj) da biet Trong thuc te, cac tham s6 kh6ng phai la mgt hang s6, chiing lu6n thay d6i va ta kho co the tinh loan chiing mgt each chinh xac Su gia dinh cac tham s6 se lam giam tin cay ciia viec minh giai dja vat ly gieng khoan mgt s6 cac truang hgp sau: • Xdc dinh rdng tir duong cong diin tr& (Schlumberger, 1989) , \\l m (R mf (t> = aR V xo J do: R^y la dien tro ciia duong MSFL (Q.m), /?m/la dien tro cua mud filtrate (Q.m), a la he s6, m la he s6 cau true Gia djnh o day la: R,„f, a, m da biet • Xdc dinh rdng dugc tu du&ng sieu dm (Wyllie et al, 1956) A _ LOG ma tJ r-t ma do: hoG la gia trj dge dugc tren duong sonic (p.s/ft), t,„a la khoang thoi gian truyen song khung da, va tf la khoang thai gian truyen song chit long bao hoa (189 jis/ft d6i voi nuoc nggt) Gia djnh o day la: /,„„, //da bilt • Xdc dinh rdng dua vdo duong natron (Schlumberger, 1989) A W-W ma W -W ' w ma 512 u'ng dung mang noron nhan tao tinh toan rdng^ do: W la gia tri hydro dugc theo duong cong natron, W^a la gia tri hydro ciia khung da, va W,, la gia trj hydro nuoc Gia dinh o day la: W,„a, W,, da biet • Xdc dinh rdng theo du&ng cong mat (Schlumberger, 1989) P X_ ~ Pu ma b P ma - PJr do: p„^a la mat ciia khung da (g/cm^) Pb la mat kh6i glcvc?, va PJ\Q mat ciia chat long da chiia, co gia tri tir 0,8 g^cm-^ (dau) den 1,2 g/cm-" (nuoc man) Gia djnh a day la: p,„a, pj da biet Them nira, cac yeu t6 khae nhu tinh kh6ng d6ng nhat ciia he hay he bj nhiem ban boi dung dich khoan, set, r6ng thii sinh, hydroeaebon nhe, v.v ciing lam anh huong den tinh chinh xac ciia viec xac djnh r6ng To hgp cac duong cong notron mat do, duong sieu am - mat va duong sieu am - natron cho tin cay cao hon viec tinh loan r6ng (Schlumberger, 1989) nhung ben canh ciing van mgt s6 dieu bat lgi (Hans, 2001) Do tham diing de xac dinh cho mgt he cho phep cac chat long di qua no Gia trj gradient dien tro dugc diing de tinh toan tham ciia he de xuat bai bieu d6 minh giai dja vat ly gieng khoan ciia Schlumberger Bieu d6 sir dung cac phuong trinh (Schlumberger, 1979) ' 2.3 k = C a* P w - Pl '^h ^ a = AD * — «g do: C la hang s6, thuong liy gia trj khoang 20, AR la sir thay d6i dien tro (ohm-m), AD la su thay d6i chieu sau img voi gia trj dien tro AR (ft), Rn la dien tro ciia he bao hoa nuoc 100% (ohm-m) Tuygn tap bao cao Hoi nghj KHCN "30 nam Dau Viet Nam: Co hoi mdi, thach thiic mdi" 513 p,, la mat ciia nuoc he (g/cm ), va A la mat ciia hydroeaebon (g/cm ) Gia dinh a day la: R, p,,, p/, da biet Do thim ciing dugc ghi nhan nhu la mgt ham phirc ciia cac yeu t6 ngi tai ciia he nhu mat do, phan chat long 16 r6ng va r6ng Vi vay, tham tinh loan tir cac duong cong dja vat ly gieng khoan thuong phu thuge vao r6ng M6i quan he tir thuc nghiem chung giira r6ng va tham dugc de xuat boi Wyllie va Rose, co kel hgp vai bao hoa nuoc du se c6 dang nhu sau sy wi k tham (md), ^ r6ng, 5'„,, bao hoa nuoc du Do r6ng cao thuong img voi tham cao nhung ciing c6 nhiing truong hgp ngoai le Kich CO, hinh dang 16 h6ng, miic lien tuc cung nhu t6ng r6ng se anh huong den tham ciia he MANG NORON ANNs kh6ng la mgt ky thuat moi Do vay, chiing t6i se kh6ng gioi thieu chi tiet ve ANNs phan Tuy nhien, muc dich ciia nghien cim dugc thiic day boi nhirng ket qua gan day ve m6 hinh ANNs ciia Huang va n.n.k (1996), Huang va Williamson (1997), va Hans ciing n.n.k (2001) Chiing t6i da ap dung huong nghien cim tuong tu ciia cac tac gia cho cac s6 lieu thu thap dugc tir cau tao Vimg D6ng, them luc dja phia Nam Viet Nam Vi vay, bao cao kh6ng phai la de mgt huong nghien cim moi ma nham phat trien mang noron de co the ap dung dugc cho khu vuc nghien cuu viec quan ly va khai thac th6ng tin cho hieu qua, chinh xac va t6t nhat De huan luyen mang noron, chiing t6i da ap dung phuong phap hgc ph6 bien nhat, lan truyen nguge, nhu la phuong phap huan luyen Tuy nhien, phuong phap lan truyen nguge lai bao g6m nhieu m6 hinh nhu lan truyen nguge true tuyen, lan truyen nguge theo kh6i, lan truyin nguge kieu delta-bar-delta, lan truyin dan hii (RPROP) va lan truyin nhanh Sir khae co ban giii-a cac m6 hinh la phuong phap tinh loan trgng s6 va cap nhal chiing (Werbos, 1994) Chiing t6i se trinh bay co so toan hgc cho ca lan truyen nguge theo kh6i va lan truyen nhanh, la hai m6 hinh cho kit qua tit nhit da dugc ap dung nghien ciru 514 Ung dung mang noron nhan tao tinh toan rfin^^^^ Phiro-ng phap lan truyen ngu-ffc Thuat ngii- lan truyen nguge (BP) dua tren phuang phap tinh loan sai so dii vai mot mang lan truyen tien, truyen thang nhung ap dung quy tic mic xich cho cac phep tinh co ban (Werbos, 1994) Mang lan truyen tien la mgt mang kit qua diu ciia m6i lorp se dugc cung cap cho cac lop ke tiep cac nh6m Bang su mo rong, BP da dl cap den mgt phuong phap huan luyen ma sir dung sir lan truyen nguge de tinh loan gradient BP la mgi nhiing m6 hinh dau tien (Rumelhart va n.n.k., 1986) dua mgt phuang phap he th6ng cho viec huan luyen cac mang nhieu lop Trong thuc te, mang lam viec a che chuyen tiep chi pha hien thi th6ng tin (kiem tra), tire la cac gia tri trgng s6 dugc c6 dinh dirt khoai, nhung nguge lai pha huan luyen, cac sai s6 dau ciia mang dugc lan truyen nguge tir lop dau toi cac lop an va lop dau vao BP voi co so toan hgc viing chac co kha nang tao rat nhieu ket qua phong phii va phirc hgp De biet them chi tiet ve dac tinh hgi tu cua mgt lan truyen nguge, phep xap xi th6ng ke va cac phuong phap lien quan den no, xin hay xem Bertsekas va Tsitsiklis (1996) Qua trinh huan luyen bat dau bang tat ca cac trgng s6 cho gia nho nhat lu6n khae khong Nhimg gia trj thuong dugc tao mgt each ngau nhien Mgt tap hgp ciia cac mau huan luyen se dugc dua lan lugt vao mang Mgt phep sai sl cho phep ciia mang dugc thiet lap va cac trgng s6 dugc cap nhat de cho sai s l giam di Khi mgt tap hgp vugt qua dugc chu trinh thi het mgt ky Qua trinh dugc lap lai lien tuc cho den toan bg tap hgp dat toi gia trj nho nhat Gia sir rang, chiing ta dang co tap miu huin luyen P va sir kich hoat dung cua noron diu ray ggi la tpj, sir kich boat quan sat dugc la Opj va n la s6 noron dau Trong m6i lan hiln thj, qua trinh huin luyen bit diu mgt phin tir xuly (PE) ciia lorp dau vao nhan cac gia trj m6 phong ben ngoai ma da vugt qua dugc cac PEs ciia nhiing lorp an Tin hieu tir nhimg PEs lop diu vao dugc nhan len bori cac trgng sl ket n6i tiep hgp va t6ng toan bg ket nii se dua moi PE vao mgt ting In diu tien, voi kit qua dau dugc tinh toan nhu sau: out =Tw O PJ • Jl Pi do: w^, la trgng s l kit nii tich hgp tir phin tir xir ly PE, din PEj ting kl tilp, va Op, la gia trj cua phin tir xir ly PEi dii voi kilu P (Lippman, 1987) Dau dugc sira d6i boi mgt ham chuyin giao dl tao nen boat dgng ciia phin tir xir ly PE Mgt ham chuyen giao bien nhit la ham sin, la ham dac trung lien tuc, mgt ham tang don dieu va co the m6 ta mgt each t6t nhat nhu la mgt ham s l co buoc uyen chuyin va co thi dugc bieu diln: o = • PJ l + e-' Tuygn tap bao cao Hoi nghj KHCN "30 nam Phu Viet Nam: CQ- hoi mdi, thach thiic mdi" >n z la tham so diu ciia bat ky phan tir xir ly PE nao mang Ham xichma dugc sir dung boi vi dao ham ciia no co dang phan b6 Gauss giup cho viec 6n djnh lai mang va bii lai su dieu chinh qua mirc ciia trgng s6 (Lippman 1987: Poulton va n.n.k., 1992) Trong thuat loan lan truyen nguge, trach nhiem giam thieu sai s6 dugc chia cho lat ca cac trgng s6 kel noi D6i vai m6i kieu sai so Ep dugc tinh loan tai lop bang binh phuong ciia hieu giOa tham s6 dau ky vgng va tham so dau thuc te nhu sau: E \2 \ n r =- Y t -O PU P n-^iKPi Neu CO m kieu dugc dua vao mgt ky thi sai s6 thuc sau m6i ky se dugc djnh nghTa nhu sau: m E =~ Y E e m^^i P Trong m6 hinh bien hoa phan h6i nguge theo kh6i, trgng s6 dugc cap nhat lien luc theo phuang trinh: / X dE(t) Aw {t) = -r/ ^y- + aAw (t-\) Ji^ ^ dw (t) Ji^ ^ 7' Awj, la su thay d6i trgng so q la mirc tiep thu ciia mang va a la momen keo mang t6i thieu thoat khoi quy tich ciia no Mot kieu tiep thu khae ciing dugc quan tam la kieu lan truyen nhanh (Ramasubramanian va Kannan, 2004) Day la phuong phap huan luyen dua tren nhti-ng gia djnh sau day: - E(w) d6i vori moi trgng so co the uoc tinh xap xi bori ham parabol m o theo huong di len, - Sir thay d6i d6c ciia E(w) d6i vai m6i trgng s6 khong bj anh huong boi tat ca cac trgng s6 khae chiing thay d6i d6ng loat Cach cap nhat trgng s6 dugc bieu dien nhu sau Aw(0 ^ ' A' cr,^ ^'^/A -r- ",^^ ^-^ Aw{t -1) - riSit) S{t-\)-S{t) ,-> ^ • X, , X,, S{t-\)-S{t) S{t) = ^— (/) • u so la dao ham cua sai so ung voi so va dyv • to t, Aw(/-l) la xap xi su chenh lech xac djnh ciia dao ham bae Ciing voi phuong phap xip xi Nevvlon cho \iec loi ihieu hoa ham mot chieu de tranh nhu'ng buoc Ire v6 ban hay buoc nhay vgt 516 Ung dung mang noron nhan tao tinh toan rong liii, mgt tham so {p) dugc ggi la he s6 gia tang lan nhit dugc dua vao Kh6ng co sir ihay d6i trgng sl nao dugc phep Ion hon p lan ciia sir thay d6i trgng sl truac Sir lan truyen nhanh CO tham sl vl miic tiep nhan c6 djnh ;;, can dugc lira chgn cho phii hgp vai bai loan THIET KE MANG v A • ITNG DUNG • Nhiing ylu t l quan trgng nhat cho viec thiet ke va thuc hien viec irng dung mang noron la lira chgn m6 hinh hgc ciia mang, each hien thj dir lieu, lira chgn each huan luyen va cac vi du kilm tra, s6 cac lop an ciing nhu cac phan tir xir ly PEs ciia no (Baum va Haussler, 1989) Sir lira chgn viec huan luyen va cac vi du kiem tra la dieu kien quyet djnh hieu suat t6t nhit ciia mang Mgt vai tac gia (Baum va Haussler 1989; Mehrotra va n,n,k., 1991) da nghien cim t6ng quat nhat ve quy m6 doi hoi cho mgt he huan luyen mang t6i uu Dieu co the noi chung la, cac mang Ion va cac kieu tham so dau vao phirc tap doi hoi can co them nhti-ng vi du cho mgt sir t6ng quat t6i uu (Kung and Hwang, 1988; Rajavelu et al., 1989) Trong nghien ciru nay, chiing t6i da thiet ke va thuc hien hai mang de huan luyen va kxiem tra r6ng va tham Trong ca hai truang hgp huan luyen mang cho r6ng va tham, chiing t6i nhan thay rang cau true mang lop la hieu qua nhat Cau true ciia nhimg mang sir dung da dugc trinh bay or Hinh vai lop dau vao g6m nut Sau nut dai dien cho sir phan h6i ciia cac duong natron, mat do, sieu am, dien tro (LLS, LLD va MSFL) Mgt lop an don g6m nut va mgt lop dau chi co mgt nut diing de bieu dien cho r6ng hay tham Vai nhiing s6 lieu cua khu vuc nghien ciru nay, cac lop an nhieu hon hoae co nhieu noron hon m6i lop se kh6ng co hieu qua va lam cho viec tinh loan tro nen phire tap hon Ngu6n s6 lieu huan luyen cho cac mang r6ng va tham da dugc lay tir gia trj tren mau loi Chiing t6i da thuc hien thuat toan lan truyen nguge theo khii de huan luyen mang r6ng voi mang tham, chiing t6i nhan thiy ring thuat toan lan truyen nhanh, hieu qua hon Huan luyen va kiem tra mang no-ron Hinh chi sai s6 RMS nhu la mgt ham cua s6 buoc lap huan luyen he th6ng s6 lieu r6ng Sai s6 bat dau Ion va se giam di theo qua trinh lap cho den no dat toi mgt gia trj gan nhu mgt hang sl khoang 0,02 sau 6291 buoc lap, mang dat lai sir hgi tu Thai gian doi hoi cho sir hgi tu vao khoang phiit d6i voi may Pentium IV 2.80 GHz CPU M6i lan mang dat din sir hgi tu, cac trgng sl dugc dieu chinh lai va luu lai file trgng s6 Sir dung nhiing trgng so da dugc dilu chinh lai nay, mang se thuc hien viec xac dinh r6ng true tilp tir cac duong cong dia vat ly gieng khoan chi vong vai giay ma kh6ng can thiet phai huan luyen them nua Tuygn tap bao cao Hoi nghj KHCN "30 nam Dau Viet Nam: Co hoi mdi, thach thiic moi" 517 Hinh 5b chi sai s6 RMS nhu la mgt ham ciia s6 buoc lap huan luyen lap hgp sl lieu rong Trong khu vuc nghien cim a cau tao Vimg D6ng, cac tai lieu thim ciia miu loi dugc su dung de huin luyen NN kh6ng 6n djnh Do la ly tai sai sl lai bit diu kha cao khoang 58 nhung sau lai giam rat nhanh din gia tri 0,1 chi sau co 800 buac lap Su h6i lu cua sai s6 dai den gia lri 0.05 sau 1143 buac lap Processing elements (a) Connection weights RMS Error vs Training Time 0,09 0.08 ^ 0.07 t 0.06 ^ ^ T r a n i n g Error >°= O04 "^ 03 0,02 001 ^ 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 5500 6000 6500 7000 Por/Per Epochs (b) Output layer RMS Error vs Training Time Hidden layer 100 MSFL 200 300 400 500 600 700 800 900 1000 1100 1200 1300 Epochs Input layer Hinh 4: Cau true cua mang noron de du- doan rong va tham Hinh 5: Sai so RMS nhu la ham ciia so bude lap huan luyen (a) rong, va (b) tham Nhung mang da dugc huan luyen boi phuang phap thir va sai dii voi mli dai dien cho cac s6 lieu cho gia tri sai so nh6 nhit Trong lan truyin nguge, mirc tilp nhan qua thip se lam cho su thu nhan cua mang rit cham mirc tilp nhan qua cao se lam cho cac trgng s6 va cac ham sai sl roi xa vi thi se kh6ng co sir tilp nhan nao ca Dl khic phuc linh hinh nay, chiing t6i da su dung cac gia trj co djnh 0,1 va 0,5 doi voi mirc thu hii ;; va momen a tuong irng Mac dii viec sir dung nhung gia trj thip nhu vay co thi lam tieu lin thai gian nhmig chiing se cho nhimg kit qua chinh xac hon iing dung mang noron nhan tao tinh to^n rong 518 De huan luyen cac mang, chiing t6i da sir dung tap hgp cac s6 lieu tir mau loi, khoang 70 s6 lieu cho mang tinh toan rong va 65 s6 lieu cho mang tinh toan tham Viec bieu dien cac mang r6ng va tham da dugc kiem tra bang viec sir dung 27 kieu mau va 33 bg mau kiem tra tuong img (Hinh 6, 7) (a) (a) RMS Error Vs Pattern for all Nodes 0.11 RMS Error Vs Pattern for all Nodes 0.11 0.09- ;0.07- sOO^ LU 0,04- 0.02- III ,l,ll II ,1,1.1 II ,1,1.1 III ,1, ll I I I , I , !,.ll.l 17 25 33 Pattern* 41 49 57 65 70 17 (b) 25 33 Pattem# 41 49 _ 57 (b) RMS Error Vs Pattern for all Nodes RMS Error Vs 'attern for all Nodes 0.10; I 0,081 sting D Error ' h- ; l l I II M l 13 Padsm* 17 21 25 • 27 Hinh 6: Sai so RMS nhu la mot ham cua cac mo hinh huan luyen va Idem tra ciia mang rong doi voi (a) tap hop so lieu huan luyen; (b) tap hop so lieu kiem tra 0.00 1 III I.I e 13 III I.I 17 f^ttem# 21 1 25 III 29 33 Hinh 7: Mot vi du khae ve sai so RMS nhu la mot ham cua cac mo hinh huan luyen va kilm tra ciia mang rong doi voi (a) tap hop so lieu huan luyen; (b) tap hop so lieu kiem tra KET QUA VA THAO LUAN Cac s l lieu dugc sir dung viec thilt kl mang dugc thu thap tir mgt s l gilng khoan clu tao Vimg D6ng Chung t6i da sir dung ANNs dk du doan ring va thim tir cac s6 lieu dja vat ly gieng khoan cua cac gilng khoan o clu tao Vimg D6ng So sanh gi&a viec tinh toan bing ANNs va phuong phap tinh toan thong thuong cho r6ng va tham voi cac gia trj tren miu loi dugc trinh bay or Hinh va 519 Tuygn tap bao cao Hoi nghj KHCN "30 nam Dau Viet Nam: Co' hoi moi, thach thuc moi" ~(a) (a) ~ 220 200 iao " ISO CORE porosity ANN pofosity 11 140 ^ 120 CS 100 * ul \ ^N * ^v \ a> 60 LOG porosity g - CORE permeability -ANNpemieability u - LOG permeability \J 60 40 20 2219 2221 2223 2225 2227 2229 2231 2233 2235 2237 2171 2172 2173 2174 2175 2176 2177 2178 2179 2180 21B1 2182 2183 2239 depth (m) depth (m) (b) (b) 330 (1 300 1^ _270 f ^ E 240 —•— CORE porosity —•— ANN porosity —»—LOG porosity J 210 180 S 150 °- 90 eo 30 2170 2175 2180 2195 2190 2195 2200 2205 2210 - ^ CORE permeability ffl -ii— ANN pemieabitity -*- LOG pemieability V 2178 2180 2184 2188 2192 2196 2200 2204 2208 2212 2216 2220 depth (m) depth (m) Hinh 8: So sanh ket qua tinh toan rong bang ANNs va phuoTig phap thong thuong vffi gia trj mau loi cho GK (a) VD-IX, (b) VD-2X Hinh 9: So sanh ket qua tinh toan tham bang ANNs va phuong phap thong thucmg vol gia tri mau loi cho GK (a) VD-IX, (b) VD-2X Cac gia trj r6ng va tham tir cac gieng khoan khu vuc nghien cim co the dugc sir dung de ve cac ban d6 phan b6 (Hinh 11) Phan b6 r6ng dugc ket hgp voi ket qua minh giai dia chan de xac djnh vj tri cua cac dut gay (Hinh 10, 11 va 12) vi nhting dai co r6ng t6t thuong lien quan voi cac dirt gay nio 7.12 7.14 7.1B 7.18 7.2 X Coordinate (mE) 7.32 72A xio' Hinh 10: Cau true ciia be mat mong ciia cau tao Virng Dong theo ket qua minh giai dia chan (theo Huyin, 2003) Hinh 11: Su- phan bo rong ket hop voi so lieu dia chan de du doan cac dirt gay ehinh cho tang 1, cao hon be mat mong khoang 100m (theo JVPC, 2001] Huyin, 2003) u'ng dung mang noron nhan tao tinh toan rong 520 • ' : 15002000- O •§ 2600- 9^ ^ 3000 3600- 7.1 M10' •ordinate (mE) Hinh 12: Cac diit gay phat trien tren be mat mong cau tao Vung Dong Oheo Huyin 2003) KET LUAN Sir dung phep gan diing qua mang noron de tinh toan r6ng va tham tir cac s6 lieu dia vat ly gieng khoan co mgt s6 uu diem hon so voi nhiing phuang phap th6ng thuong chi diing nhting cong thirc thuc nghiem dua vao cac m6 hinh hoi quy tuyen tinh hay cac c6ng thirc ban thuc nghiem ph6 bien, nhu phuong trinh ciia Wyllie va phuong trinh mat diing de du doan r6ng hay cac phuong trinh cua Schlumberger viec du doan tham Phuong phap mang noron dugc dua nhu mot huong rat thuc te de giai quyet cac bai loan nguge ciia phuang phap dia vat ly gieng khoan c6 dien van dugc diing nhieu nam qua voi nhung \an de l6n dong ma nhieu the he cac nha khoa hgc trai dat cung nhu cac ky su dau luon tran tro Thay vi lim nhting moi lien he ben rat phirc tap gitra cac dac linh dia chat \ a dja vat ly a phuong phap tinh toan th6ng thuong, phuang phap sir dung mang noron kh6ng doi hoi mot m6 hinh toan hgc uu tien hay mgt su gia dinh tuyen linh nao cac bien s6 Trong nghien ciru nay, chiing t6i nhan th4y rang thuat loan lan truyen nguge theo kh6i la mot mo hinh tien lgi nh4t cho hu4n luyen mang NN tinh toan r6ng ihi lan lru}-^n nhanh duoc lh^>- la t6t nhk doi voi tap hgp s6 lieu cho tham Mang sau da Tuygn tap bao cao Hoi nghj KHCN "30 nam D^u Viet Nam: Co hoi moi, thach thuc mdi" 52^ dugc huan luyen xong dugc ki^m tra bang tap hgp cac s6 lieu tir mau loi de hieu sual cua no Ban d6 phan bo rong va th^m a ciing mot chieu sau ciia cac gieng khoan a cau lao Virng D6ng da dugc xay dimg va lien ket voi cac ket qua minh giai dia chan de du doan nhung dirt gay chinh hay cac doi nut ne Cac ket qua thu dugc chi rang phuong phap de bao cao co nhiSu dieu hira hen ANNs nen dugc dua vao ap dung rong rai Irong nganh c6ng nghiep dau Viet Nam TAI LIEU THAM KHAO Baum E., Haussler D., 1989 What size net gives valid generalization! Advances in Neural Information Processing Systems I (ed D Touretzky), Morgan Kaufman, p 80 90 Bertsekas D.P., Tsitsiklis J.N., 1996 Neiiro-dynamic programming Athena Scientific, Belmont, MA, p 178- 183 El-Qady Gad, Keisuke Ushijima, 2001 Inversion of DC resistivity data using neural networks Geophysical Prospecting 49, p 417 - 430 Hans B Helle, Alpana Bhalt, Bjom Ursin, 2001 Porosity and permeability prediction from wireline logs using artificial neural networks: A North Sea case study Geophysical Prospecting 49, p 431 - 444 Huang Z., Williamson M.A., 1997 Determination of porosih' and permeability in reservoir intervals by artificial neural network modelling, offshore Eastern Canada Petroleum Geosciences 3, p 245 - 258 Huang Z., Shimeld J., Williamson M., Katsube J., 1996 Permeability prediction with artificial neural network modelling in the Venture gas field, offshore Eastern Canada Geophysics 61, p 422 - 436 Huyen B.T.T., 2003 Study on subsurface structure and rock properties based on 3D seismic data and well log data Master Thesis, Kyoto University, Japan (unpublished), p 22 - 24 .lapan Vietnam Petroleum Company (JVPC), 2000 Report for the Block 15-2 prospect, Southern offshore Vietnam JVPC reports, p 41 - 42 Japan Vietnam Petroleum Company (JVPC), 2001 Report for the Block 15-2 prospect, Southern offshore Vietnam JVPC reports, p 103 - 104 10 Kung S Hwang J., 1988 An algebraic projection analysis for optimal hidden units size and learning rates in back propagation learning Proceedings of the T' IEEE International Conference on Neural Networks, Vol (eds M Caudill and C Butler), SOS Printing, San Diego, CA, p 363 - 370 522 Ung dung mang noron nhan tao tinh toan ron^^^ 11 Lippman R., 1987 An introduction to computing with neural nets IEEE Transactions on Acoustics, Speech and Signal Processing 4, p - 22 12.Mehrotra K., Mohan C , Ranka S., 1991 Bounds on the number of samples needed for learning IEEE Transactions on Neural Networks 2, p 548 - 558 13 PetroVietnam (PV), 1998 Report of Cuu Long basin, southern offshore Vietnam PV reports, p - 14 Phuong L.T., 1997 Lithofacies and depositional environments of the Oligocene sediments of the Cuu Long basin and their relationship to hydrocarbon potential Proceedings of an International Conference on Petroleum Systems of Southeast Asia & Australia, Jakarta, May 21-23, IPA, p 531 - 538 15.Poulton M., Sternberg K., Glass C , 1992 Neural network pattern recognition of subsurface EM images Joumal of Applied Geophysics 29, p 21 - 36 16 Raiche A., 1991 ^ pattern recognition approach to geophysical inversion using neural networks Geophysical Joumal Intemational 105, p 629 - 648 17 Rajavelu A., Musavi M., Shirvaikar M., 1989 A neural network approach to character recognition Neural Networks 2, p 387 - 393 18 Ramasubramanian P., Kannan A., 2004 Quickprop neural network ensemble forecasting framework for a database intrusion prediction system Neural Information Processing, Letters and Reviews 5, No 1, p 109 - 118 19 Rumelhart D.E., Hinton G.E., Williams R J., 1986 Learning internal representations by error propagation Parallel Distributed Processing: Explorations in the Microstructure of Cognition, Vol (eds D.E Rumelhart and J.E McClelland), MIT Press, Cambridge, MA, p 318-362 20 Schlumberger, 1979 Log Interpretation Corporation, New York, p 82 - 83 charts Schlumberger Well Surveying 21 Schlumberger, 1989 Log interpretation: Principles and applications Schlumberger Educational Services, Houston, chapter 5, p 10 22 Werbos P J., 1994 The roots of back-propagation John Wiley & Sons, Inc, p 115 - 127 23 Wyllie M.R.J., Rose W.D., 1950 Some theoretical considerations related to the quantitative evaluation of the physical characteristics of reservoir rock from electrical log data Joumal of Petroleum Technology 189, p 105 - 118 24 Wyllie M.R.J., Gregory A.R, Gardner L.W., 1956 Elastic wave velocities in heterogeneous and porous media Geophysics 21, p 41 - 70 ... VlfNG DONG Cau tao Vimg D6ng nam be Cim Long (Hinh 1) them luc dia phia Nam Viet Nam Be tram tich la mgt khu vuc trien vgng nhat cho viec tham va khai thac dau a Viet Nam va dugc hinh ky Kainozoi... voi mli dai dien cho cac s6 lieu cho gia tri sai so nh6 nhit Trong lan truyin nguge, mirc tilp nhan qua thip se lam cho su thu nhan cua mang rit cham mirc tilp nhan qua cao se lam cho cac trgng... D6ng Bae - Tay Nam va D6ng - Tay Hinh dang cau triic dugc cho ring bit nguon tir sir trugt bang tren dirt gay S6ng H6ng va sir mo bien Nam Trung Hoa thai ky Kainozoi (Huyen, 2003) Trong nghien