150 SIX bien doi mot so chi tieu dja h6a quan trong cua dau trong qua trinh di cu cung nhu* kjiai^th^c •? ^ s i r BIEN DOI MOT SO CHI TIEU DIA HOA QUAN TRONG CUA DAU TRONG QUA TRINH DI CLT CUNG NHU^ K[.]
150 SIX bien doi mot so chi tieu dja h6a quan cua dau qua trinh di cu cung nhu* kjiai^th^c •? ^ s i r BIEN DOI MOT SO CHI TIEU DIA HOA QUAN TRONG CUA DAU TRONG QUA TRINH DI CLT CUNG NHU^ KHAI THAC Hoang Dinh Tiln, Nguyin Thuy Quynh XNLD Vietsovpetro TOM TAT Bdi viet neu buc tranh todn cdnh vi xdc dinh vgt lieu ngudn gdc vd muc biin chuyin hod cua vdt lieu hiru co (VLHC) Ddc biit bdi viet mudn de cap suphan bd lgi cdc gid tri cua mdt sd cdu tu nhe so v&i cdc cdu tu ndng qud trinh di cu vd khai thac tren nguyen tdc phdn di trgng lire Mdt sd cdu tu nhe nhu; drimane, nCp, pristane, phytane, tricyclic terpane, tetracyclic terpane, Ts, Tm, cholestane, ergostane, sitostane so v&i nCoy, C30 oleanane, C30 hopane, v v ty sd Pr/Ph chiu tdc ddng cua phdn di luc khd ro Chinh vl thi cdn phdi so sdnh cdc chi tieu ndy vdn cdc chi tieu khdc hydrocarbon (HC), ddng then xdy dung mdi quam hi v&i cdc chi tieu eua kerogen da me phdn bd & d&i truong thdnh, ddc biet & d&i tru&ng thdnh s&m giiip ich cho viec xdc dinh hudmg vd khodng cdch di cu ciia HC Dau va la cac chat hydrocarbon rat linh dgng co ty trgng lu6n nh6 hon nuoc Dac tinh ly hoa, dia hoa ciia chung le thuge vao nhieu yeu t6 nhu ban chat ciia vat lieu htru co, ngu6n, mirc truong ciia chiing va m6i truong ma chung di cu den diem tich lijy Ban chat ciia vat lieu hiiu co va qua trinh truong cua chiing dugc nghien ciru rat nhieu va dugc dang tai tren nhieu tap chi va hgi nghi qu6c te Chang han nhu ngu6n vat lieu hun eo: Neu la kerogen loai I duge tieh luy ehii yeu m6i truong dam h6 co uu the sinh dau, kerogen loai II dugc tich liiy chii yeu m6i truong h6n hgp (cira s6ng, nuoc Ig, bien n6ng, v.v.) co uu the sinh dau va nhung nghieng vl phia dau Kerogen loai III dugc tich liiy chu yeu m6i truong lyc dia co uu thi sinh va phan rat nho hydrocarbon long vi vay san pham cua chiing la condensat va khi, rit it diu Mirc bien chat ciia VLHC ciing dugc nhieu chuyen gia co tac gia da nghien cim ti mi va cho biet birc tranh chung nhu sau: - doi tao da (diagenez) mire bien chat thap Da tram tich chii ylu giai phong nuac ty va CO2 - doi chuan bi truong (protocatagenez) VLHC a dod sinh hoa sau bit diu birt pha cac nhanh - goc hydroxil, carboxil va pha huy cac acide humic Dae biet chiing dugc tai tao lai boi vi khuan yem nen mgt sl loai dugc sinh nhu CH4, NH4, mgt phan CO2, H2S, NO2, v.v Ket thuc giai doan trim tich bat dau gan ket eon VLHC ket thuc qua trinh dirt va cac mach nhanh hydroxil, carboxil va acide humic, v.v - Doi truang som (giai doan mezocatagenez som) bat dau birt pha cac phan tir hun CO va giai phong mgt phan hydrocarbon va 16ng nhe VLHC a doi bi Tuygn tap bao cao Hoi nghj KHCN "30 nam DSu Viet Nam: Co' hoi moi; thach thiic moi" 151 biin dii nhiet tuong duong voi phan xa cua vitrinit (R^) = 0,5 -^ 0.6% den 0,8%o Phin Ion HC dugc tao van nam da me Dai truong (mezocatagenez gitra va mugn) - RQ = 0,8 -^ 1,35% Trong doi nay, cuong sinh dau manh dan den tang s6 lugng hydrocarbon (l ^ 4,2%) thi chi sinh CO2 va H2S dut vo O2 va S tir da O doi VLHC co xu huong grafit hoa (gan nhu chi la carbon) Tren day la so chung cua qua trinh sinh hydrocarbon long va khi, chiing dugc sinh chii yeu yeu t6 nhiet do, co the co xiic tac cua khoang vat set, yeu to ap suat la thir yeu Song de di cu dugc thi yeu t6 ap suat noi tai ciia HC va ap suat dia tinh dong vai tro quyet dinh Trong qua trinh di cu xay phan di trgng lyc, tiic la cac cau tir hydrocarbon cang co cau tnic ggn, nhe cang di cu nhanh hon va xa hon Sy phan b6 lai trgng lyc ciia HC xay bat ky hinh thuc di cu nao dii mgt pha long cua HC hay hai pha (nuoc va long boi lyc n6i ciia cac gigt dau hay bi nuoc day.di) hoae duoi dang nhan missel Vi vay pham vi khu mo, cang xa via dau ty le metan so vai cac nang khae cang tang cao ham Iugng cac nang HC nhu C2, C3 va C4 cang xa ngu6n cang giam dan D6i voi cac cau tir nang hon cting dien qua trinh tuong ty - cang xa ngu6n ham lugng cau tir nang HC cang giam dan Theo Hoang Dinh Tien va cac d6ng nghiep khae, a mong mo Bach H6, D6ng Bae R6ng thuge be Cim Long co cac via condensat va diu nhe dugc tach tir dau da mong mo bach H6 [1] Nghien cim mau dau a khu vuc tren hoae dau va condensat m6 Dai Hiing (thuoc be Nam C6n Son) deu thay phan anh rat ro hien tirgng phan di trgng lyc qua trinh di cu Ham lugng hydrocarbon no (HCsat) tang cao theo khoang each di cu, nguge lai hydrocarbon thom (HCar) giam dan vi co cau tnic c6ng kenh, phirc tap va nang hon HCsat Gia tri ty s6 HCsat/HCar tang dan tir 9,97 mong mo Bach H6 toi 14,61 dau va 47,4 a via condensat mo D6ng Bae R6ng O m6 Dai Hung ty s6 tang tir 5,62 a via diu toi 28,7 a via condensat (Bang 1) Chi s6 alkin eting phan anh quy luat nhu vay vi nCn nhe hon nhieu so voi nC27 Chi s6 sinh hgc Bi, Hn va H12 cang tang eao cac san pham di cu Vi du B| dau mong Bach Ho chi dat 221,51 nhung diu nhe Dong Bic Ring da tang toi 251,3 nhung condensat a D6ng Bic Ring tang cao hon toi 334,25 -^ 334,30 don vi Vi ring drimane CO trgng lugng phan tir la 208,0 s6i 291C C23Tricyclie va C24tetracyclic terpanes co trgng JS ^ o H II C3 II fsl c a, o O c a c ^—» 11 H o •X 52.00 17.00 31.00 2.09 0.74 46.10 16.43 37.47 2.10 0.72 26.84 4.12 173.56 14.66 10.69 133.73 60.63 11.12 108.23 56.00 18.00 26.00 1.89 0.77 57.46 32.34 79.41 97-670 138 93.66 18.12 107.16 19.02 33.48 47.56 5.61 0.50-0.62 0.56 3.78-54.7 7.61 5.81 39.20 7.65 41.13 6.04 59.80 6.38 u 00 r-t u ON PN) U B d a 0.57 6.15 32.15 30.44 37.06 36.14 52.66 15.85 74.61 9.64 6.06 43.94 50.00 6.06 0.55 56.11 35.68 86.70 6.00 35.00 59.00 6.02 0.57 1849.93 465.20 29.47 38.92 31.26 1.81 0.72-0.77 0.74 334.3 334.25 251.3 221.51 U Pr/Ph B ISg = 4Me C30 Sterane (42) 'NV I B , = 8B(H) drimane (123) > u 3934-4022 97.64 2.06 47.40 85.07 M D M 3931-4283 95.72 3.49 27.43 81.19 KM 4308-4720 91.04 6.23 14.61 56.98 X a 3017-4385 83.44 8.37 9.97 55.3 a o kl Chieu sau SAT ARO SAT./ARO lAlkind= nC17 100 'C8 Condensat O" UD DH-IOX Ddu ldn Condensat Ddu nhe condensat 3043 - 3250 96.14 82.97 92.18 6.09 3.35 12.91 15.13 28.70 6.43 58.82 68.77 88.71 '-3 Ddu nhe U DH-I Ddu trung blnh 1984-2394 76.47 13.26 5.62 47.39 (J Ddu ldn condensat Ddu mdng Bgch Hd a 'C £)flz Himg ja Rdng - lOX (Cdnh Ddng Bde) 152 Sy bien doi mot so chi tieu dja hoa quan ciia dSu qua trinh di cu' cung nhu' khai thac ãƠ* a ao cn c ^OJ —• c3 o rJ C3N + II X Tuyin tap bao cao Hgi nghj KHCN "30 nam D^u Viet Nam: Co hpi moi, thach thuc moi' 153 Iugng phan tir tuong img la 318 va 330,58, s6i 397°C va 404°C C30 hopane co trgng lugng phan tir Ion hon nhieu - 412 va s6i nhiet cao ban - 467°C Nhu vay drimane, C23trycyclic va C24 tetracyclic nhe hon nhieu so voi hopane (Bang 2) Bang 2: Tinh chat ly hoa cua mot so cau tu* hydrocarbon quan No Cdu tu Trong lugng phdn tu Diem sdi, °C Drimane C15H28 208,0 291,0 nCiyHse 240,46 302,7 Pristane i-Ci9H4o 268,51 314,0 Phytane i-C2oH42 282,54 331,7 Tricyclic terpane C23H42 318,0 397,0 Tetracyclic terpane C24H42 330,58 404,0 Ts (C27H48) 372,0 439,0 Tm (C27H48) 372,0 439,0 C27 Cholestane 372,0 439,0 10 C28 Ergostane 387,0 448,0 11 C29 Citostane * 402,0 457,0 12 nC27H56 380,72 419,4 13 C30 Oleanane 412,0 460,0 14 C30 Hopane 412,0 467,0 Ghi chii Ciia sterane manh M/Z217 * Citostane (phucostane hoae stigmastane) Chi tieu Sg diu mong Bach H6 chi dat 107,16, song condensat lan diu va condensat D6ng Bic R6ng tang len toi 133 -^ 173,56 Cac cau tir ciia sterane nhu C27, C28 va C29 cimg co sy phan bl lai ro ret Trong diu mong Bach H6 C28 chiem uu the (toi 38,90%) song diu nhe cung nhu condensat o mo R6ng C27 lai chiem uu the (56 -^ 46,10%) O mo Dai Himg (thuoc be Nam C6n Son) diu nhe C29 chiim uu the voi gia tri cao (59,80%), song condensat gia tri giam toi 37,06% C27 tang tir 6,0%) diu nhe toi 32,15% condensat Neu khoang each di cu dii Ion, ham lugng C27 sterane co the vugt C29 sterane vi C27 nhe hon dugc tang cuong qua trinh di cu Chinh vi the neu can cir vao eae tuong quan de xac dinh ngu6n g6c va m6i trudng tich liiy VLHC co the dan den nham lan Tren thyc te, condensat va dau nhe D6ng Bae R6ng co cimg ngu6n g6c tham chi ciing miic truong voi dau mong mo Bach H6 [1] nhung di cu lai thay d6i tuong quan gitra cac chi tieu voi Khi nghien cuu chi tieu Pr/Ph ciing cho ket qua tuong tu, tire la khoang each di cu cang xa ty s6 cang tang Pristane nhe hon phytane nen se di cu nhanh hon, xa hon Vi du theo dien, dau mong m6 Bach H6 co ty s6 Pr/Ph phi biin chi dat 1,81 via dau nhe va condensat D6ng Bic Ring chi tieu cao hon nhilu so voi sl lieu ban diu 154 Su bign doi mot so chi tieu dja hoa quan t r o n g ciia dau qua t r i n h di cu- cung nhu' kha^i £hac tang toi 2,09 ^ 2,10 m6 Dai Hiing ciing xay tuong ty, via diu Pr/Ph chi dat 5.61 - 6,02 o via condensat gia tri Pr/Ph dat toi 6,15 Nhu vay o m6 Bach H6 dii tugng mong, Oligocen duoi dau co xu huong di cu tir canh D6ng Xu huong dugc thi hien ro qua cac chi tieu Ps, ty suat dau (GOR), nhot va Pr/Ph (Hinh 1, Bang 3) Theo chieu huong chi tieu Pr/Ph eo gia tri 1,77 ria can D6ng, tang toi 1,81 dai Trung tam va dat 1,95 canh Tay Trong doi tugng Oligocen duoi chi tieu Pr/Ph dat toi 1,76 o ria can D6ng va dat 1,88 a canh syt Trung tam, tang eao vom Bae va dat 1,915 (Hinh va 3) 40 42 46 44 48 % parafin -" M-M6ng ^ Vom Trung Tain ^ P' - Oligocen duoi ^ ^ ^ ^ VomBac Canli sut phia Dong Ps Pr/P A Doi tuong Oligocen duoi A Pr/Ph_ U - 2.0 J 0.5 0.4 29.4 28 350 _Pr/Ph 26 300 OOR 24 250 _1.915 0.476 '•~-"- _l.7_6 0.427 290.0 0.3 16 Ps GOR 4\ A 22.2 1.4 0.2 1.2 0I 1.0 Ps GOR JT 20.76 174.0 Vom Bae Pr/Ph 0.5 177.8 Doi tu'ong mong 1^ 29.28 150 18 100 1.6 ^ 0.3 2^2 Ps 21.05 GOR 173.2 |[ 275.1 I ; A Ps Pr/Ph 28 350 26 300 GOR 24 lb ^213.3 0.216 1.0 C§n Tay GOR /^ 0.4965 1.81 1.2 20 Can Dong | Canh sut 1.77 14 200 Ps H /N A 2.0 22 0.219 -22 20 150 18 100 C|n Dong 3000 Huong di cir ciia hydrocarbon Hinh 1: Huong di cu cua hydrocarbon ff mo Bach Ho 250 200 Tuyin tap bao cao Hoi nghj KHCN "30 nam DSu Vi^t Narn: Co' hOi moi, thach thiicjnoi" ff- Dac3>chdniUDnE