PETROVIETNAM OAC TINH CHIJA CUA TAP E, HE TANG TRA CU, LO 15 la THUOC BE CCrU LONG ThS Ho^ng Manh Tan, ThS Nguyen Hong Minh, KS Nguyen Van Hieu Vien Ddu khi Viet Nam Mdtfau Bdi viet ddnh gid tinh chdt[.]
PETROVIETNAM OAC TINH CHIJA CUA TAP E, HE TANG TRA CU, LO 15-la THUOC BE CCrU LONG ThS Ho^ng Manh Tan, ThS Nguyen Hong Minh, KS Nguyen Van Hieu Vien Ddu Viet Nam Mdtfau Bdi viet ddnh gid tinh chdt chda cua tap E, hi tdng Trd Cu (thudc Ld 15-la, be Cdu Long) dUa trin kit qud phdn tich duac thuc hiin tgi Trung tdm Phdn tich Thi nghiim - Viin Ddu Viet Nam (VPI-Labs) Od chda tap E khu vUc nghiin cdu chu yeu thudc dgng arkose, lithic arkose vd it hdn Id feldspathic greywaeke; cd dp rong trung binh 9,39%, dp thdm trung binb 0,085mD; quan hi gida kvdOed hi sd hdi quy tddng ddi cao (R^ = 0,692) Dp bdo hda nudc duac xdc dinb bdng cdch true tii'p trin mdu vd tUmdt sd duimg quan be duac thiit lap (mue 2.2) Ddy Id phuang phdp ddnh gid dp bdo bda nUdc via deso sdnh vdi cdc phuang phdp khdc, ddc biit Id ddi vdi nhdng giing khoan svf dung dung dicb khoan gdc nUdc TUket qud phdn tich dudng cong dp sudt mao ddn, nhdm tdc gid xdc djnh ddc trUng cdu true kinh rdng, gdp phdn ddnh gid khd ndng chda vd dieh chuyin cua ddu cdc kinh rdng qud trinh khai thdc; td dd de xudt cdc gidi phdp tdi uu tdc ddng vdo via nhdm tdng cUdng khd ndng thu hdi ddu Gidri t h i i u Tip E, hd ting Tri Cu (thudc Ld 15-1 a) cd tudi Oligocen sdm Trong thdi ky niy cd hoat ddng eua nui Ida dupe minh chUng bing eie d i phun trio v i tram tieh phun trio Trim tich eua t i p cich ngudn cung cap vit lieu khong xa va dupe trim tich mdi trUdng sdng (fluvial), hd (lacustrine) vdi mUc dp biln ddi sau tram tich d giai doan diagenesis Tip nghiin cUu d i phit hien ddgc eie tang sin pham diu cho ddng vdi lUu lupng cdng nghidp sd quan trpng edng tie tim kiem, thim dd diu Od rdng cua mau dupe bing phuong phip ndn heli dua trdn Ojnh luit Boyler [6] thdng qua vide xic dinh the tieh khung d i v i the tich Id rdng Op tham the hidn nang eho ddng eua via va la mdt nhdng thdng sd quyet djnh luu lUpng tien hanh khai thie Op tham tuydt ddi cua mau dupe bang thilt bj CMS-300 d dieu kidn nen hdng (NOB) theo phuong phip ddng chiy eua khdng dn dmh v i dupc xie djnh theo Ojnh luit Forheimer Trong qui trinh khoan tim kiem, thim dd tai Ld 15-la, Cdng ty Liln doanh Oilu hinh Cdu Long (Cuu Long JOC) da phit hi|n eie via dau nim tap E, he tang Tri Cu Tang nghidn cUu la eie via eit, bdt, set xen ke, phin Idp khdng diy v i ed chilu sau tU 2.900 - 4.400m Dung dich gde diu duoc sU dung de khoan cic gieng khoan tai Ld 15-la v i 104m mau Idi dupe lay tai vj tri eie gieng khoan T-2A, 3A, 4A v i N-3A thude khu vUc md T v i md N Cie m l u niy dupc phin tieh die diem thach hpc, dp rdng, dd t h i m v i i p suit mao dan bing phuong phip ming b i n thim Phan tich dp bao hda nude dU true tilp tU mau loi dupc tien hinh trdn 89 mau, bang phuong phip DeanStark [6].Trong dd, luu y van de lay mau tUgilng khoan va bio quin tdt d l khdng inh hudng din sU thay ddi him lupng nude ehUa mau Theo Kenedy, Van Meter v i Jones [7], tai eie gieng khoan sU dung dung djeh khoan gde nude cd inh hudng nhieu din dp bao hda nude ban dau eua mau d i v i trang thii bio hda nude ban dau cua mau dupe bio tdn tdt mau dUOe khoan bang dung djch gdc diu Cu t h i , cic phin tieh thach hpc dUOc tiln hinh trin cic m l u Idi, mlu vun bing cie phuong phip: nghiin cUu l i t mdng th?eh hpc (trin 200 mlu), kinh hiin vi diln td q u i t (70 mlu) v l phuong phip nhieu xa tia X (360 mau) Cic phin tich m l u Idi thdng thudng (dp rdng, dp thim v i t^ trong) duoc tiln hinh trin 225 mlu Trong dd, dd rdng thd 'lidn ning chda chit luu cua dat d i v i l i thdng Ap suit mao dan eua t i p E, he tang Tri Cu duoc xie dinh bing phuong phip mang bin tham d dieu kidn mau duoc nen i p suit tai dilu kidn via (38 mau) TU dudng eong i p suit mao dan sd xic djnh dupc su phin bd kieh thudc kdnh rdng; dU doin su phin bd chat luu via, chat lupng d i chUa v i kha nang tham gia ddng chiy eua eac chat lUu, chilu siu eua mue nude tU BAynil.so5/2oi3 17 ^ THAM DO - KHAI THAC DAU KHI O^c tinh chUa cua tap E, he tang Tra Cu 2.1 Ddc diem thgch hpc Theo kit qua phin tieh lit mdng, ddi vdi khu vUe md T [5], d i eua tap ehu yiu l i eit kit saeh hat mjn, dd chpn Ipc trung binh, thudc loai cit kit lithic arkose rat it feldspathic v i arkose (theo phin loai cua R.LFolk 1974) Oi chUa phong phu minh d i phun trio (phd bien li 10 - 20%), granite (5 -10%), chert (1 - 2%), schist (2 - 4%) v i quartzite (1 - 2%) (Hinh 1) Khoang vit thU sinh vdi phan Idn l i thach anh, calcite, zeolite (xuit hidn khdng deu) Khoing vat set xuat hidn rii ric, chu yiu l i chlorite (Hinh 2) v i it illite cung vdi hdn hpp set illite-smectite; chlorite tang din theo chilu sau v i khong cd sU xuat hien eua smectite, kaolinite Tai khu vuc md N [4], cie mau phin tich ehu yiu l i d i cit kit dang arkose, lithic arkose v i it hon l i feldspathic litharenite, cd kieh thudc hat tU rat mjn d i n thd, phd bien la hat trung binh den thd Hinh dang cic Hinh 7.06 sdu 3.831.36m - Gieng khoan T-3A ãã=, fir- lô^*ằ V hat tU bin gde canh din tron canh va it hon l i dang gde canh, dd chpn Ipc td trung binh den tdt Tilp xiic giUa cic hat da phin la dang diem v i dudng eho thiy da bj dp nen chua cao (Hinh 3) Hidn tucing xi ming hda rat manh inh hudng khdng nhd d i n nang chda eua da, eie khoing vat thU sinh lip day cie kinh rdng nhu zeolite (Hinh 4), calcite, siderite, thach anh, chlorite (Hinh 5), kaolinite v i cie khoing vit sdt khic Theo kit qua phin tieh nhieu xa tia X (XRD) cho toin bd d i , him lupng sdt trung binh dat 15% v i ehu yeu tap trung khoang - 10% Trong dd, lupng khoing v i t smectite trung binh chilm khoang 34,6% Cic khoing vat sdt phit trien manh khiln dp thim giim va ting dp bao hda nudc du d i ehUa Tram tich t i p E dupe van chuyen chUa qui xa so vdi ngudn eung d p vat lieu v i trim tieh mdi trudng nang luong eao d i n thap (nhu mdi trudng sdng, hd); CO ngudn gde eung dio magma v i mdng ning lue dja Theo kit qui phin tich thach hpc, dp rdng dupe dinh gii Hinh Do sdu 3.996,36m • Gieng khoan T-4A >^,^ ^^^1 •^ ^ • ^ > i ^ Hinh Dd sdu 972,05m - Gieng khoan N-3A 18 I t e m - s o s/2013 Hinh Do sdu 2.975Jm - Giing khoan N-3A PETROVIETNAM 2.2 Ddc diem mau Idi 2.2.1.06 rong vd thdm Theo phan tfch, mau loi, da chda cua t i p E cd rdng thap, gii trj trung binh dat 9,39%, chu yeu tap trung khoang 7-13% (Hinh 6) [1, 3] Bang cho thay da chUa d md N co dp rdng trung binh (8,50%) thap hon so vdi da chUa d md T (9,8%) Op tham cua tap E thay ddi ldn tU < 0,01 mD den hing trim mD, gia tri trung binh dat 0,085mD (Hinh 7) Quan he rdng - tham (Hinh 8) dupc tfnh theo cdng thdc sau: Log(/:) = 0,4351*-4,6990 5.06 sdu 2.975,2m - Gieng khoan N-3A 3Q 1 j ^ ^ * § •« J Quan he niy ed he sd gan kit tuong ddi eao (H^- 0,692), ed the sd dung de tfnh dp tham tai cac diem khic via biet dp rdng Op tham trung binh cua tap E d md N thap hon so vdi tham d md T (Bing 2) Ty sd giQa tham vudng gdc v i tham song song KV/KH (Bing 2) cua tap E tai md N (0,512) nhd hon nhieu so v6i moT (0,918) Oieu eho thay nang rat ldn d i tap E tai md T sd chay theo hudng vudng goc vOi mat ldp Nhin chung, day l i tap da chUa cd 66 rdng, dp tham trung binh thap, gii trj thay ddi manh theo dien phin bd Do vay, van cd kha nang tim thay khu viic m i d dd da tap E cd nang ehUa tdt hon so vdi viing nghidn eUu D 2.2.2 Do bdo hoa nUde 0 04 rSng, % mnh Bieu dd tdn sudt dd rong tap E trung binh gdm: rdng nguyin sinh phd biln (8 -12%) va mdt phin rdng thUsinh (1-1,4%).Trong qui trinh thinh tao cic khoing v i t thU sinh thudng tao cie vi Id rdng v l hlu h i t cic khoing v i t cd mUe dp trao ddi cation thip (ngoai tri/ sd luong nhd khoing vat smectite, ilite ed mdc dd trao ddi cation eao v i trung binh) Oac diem thach hoc nhu trin d i tao n i n sU khic biet nana chda cua di, thi hidn rd nhat l i him luong nudc du t h i tich cic kdnh rdng (mue 2.2) Do bao hda nUdc trung binh true tilp trdn mau Idi eiia tap E dat 41,49% Trong dd, dp bio hda nudc trung binh d md N dat 59,23%, eao hon so vdi md T (35,58%), phii hpp vdi kit qui phan tich thach hpc (muc 2.1) Chi tilt ve dp bio hda nUde tai tdng gilng khoan dupc the hien Bing Ngoii cieh true tilp trdn mau, dp bao hda nude ed the dupe xic djnh giin tiep thong qua quan he giUa ap suat mao dan vdi dp bao hda nUde hoic tUcic dudng cong dja vat ly gieng khoan Kit qui phan tieh mau Idi thdng thudng cho thiy tinh chat via eua tap cd sii biln ddi rat Idn d cic vj tri va cau tao khie Oilu niy gay khd khan vide dii bio chinh xac ning khai thie eung nhu dinh gia trd lupng Oe ed the dinh g i i tdng t h i tinh chat cua t i p ve su phin bd cua chat luu dua trdn kdt qua phan tich mau Idi, nhdm tic gii d i phin tieh tdng hpp eie dudng 19 T H A M D O - KHAI THAC D A U KHI Hmh Bieu dd tdn sudt thdm tap E cong i p suit mao dan, thilt lap cic him quan he va lUa chpn cieh xie djnh dp bao hda nUde via sit vdi thuc te nhat Gieng khoan:T2A,T-3A,T-4A, N-3A Log (Y) = *X - 4,6990 225 mau He so hoi quy R^ = 0,692 Hinh Bieu quan hi rong - thdm todn tdp E d i chUa la rat can thilt PhUOng phip lan dau tidn dupe edng bd bdi Leverett [8] va sU dung him quan hd 2.3 Ap sudt mao ddn (PJ vd dng dung viic ddnh J-Funetion: gid tinh chdt via Theo phuong phip ming bin tham, cd 38 mau tap E dugc chpn v i xic djnh dd bao hda nUde tai cic cap ap suit: 2,4, 8,15,35,70,120 v i 200psig ^ 2.