Hdi thdo khoa hoc "Ndng cao he sdthu hdi ddu md Bqch Hd " NANG CAO HE s6 THU H6I VIA DAU M6NG M6 BACH H6 BANG DUY TRI TRL/^NG AP SUAT VIA T6I IAJ Phung Dinh Thirc Cong ty Tham do Khai thac Dau khi Mai[.]
Hdi thdo khoa hoc "Ndng cao he sdthu hdi ddu md Bqch Hd " NANG CAO HE s6 THU H6I VIA DAU M6NG M6 BACH H6 BANG DUY TRI TRL/^NG AP SUAT VIA T6I IAJ Phung Dinh Thirc Cong ty Tham Khai thac Dau Mai Van Du Cong ty Dau Viet • Nga • Nhat ABSTRACT Based on analyzing the dynamic change of such resen/oir properties as permeability of the fracture (K2) and matrix blocks (KI) as well as the well's productivity in the Bach Ho basement oil resen/oir's development process, authors realized that they have the tend of nonlinear increasing at the resen/oir pressure level equal 1.11.4 bubble-point pressure Therefore, if during all development process the resen/oir pressure can be maintained at the optimized level, the oil producing rates of the wells and also of all resen/oir would be reached the highest level Anymore, the increasing of fracture and matnx permeability should cause the increasing of the oil displacement coefficient in these media and, consequently, increasing of the total resen/oir's oil recovery i.MdoAu Hang loat cac nghien eUu phdng thi nghiem va ngoai thyc dia nhu'ng nam g i n day [1, 2, 3, 4, 6, 8, 13, 14, 15, 17, 18 ] da ehUng td sy hien dien cua hieu Cfng phi can bang ddi vdi he chit Idng via mdi trudng da thim lien quan den sy hinh dot bien eae vi bao tCr khi ap suit via tien gin den ap suit bao hda ma ket qua la cac tinh chat thuy ddng hpc eua nd gia tang dang ke Theo ket qua cua nhung nghien eCru tren, via dau mdng md Bach Hd hdi tu nhieu yeu td lam gia tang cudng dp hinh hieu Ung phi can bang ap suit via cua nd tien g i n den ap suit bao hda dd la: • Tinh bit ddng nhit cao cua cac dac tinh tham chCra theo di'en tich va mat cat vdi sy tdn tai nhieu loai khdng gian rdng - micro, macro nUt ne, hang hde nhu mdt tac nhan lam gia tang manh cudng dp hinh cac vi bao tCr khi ap suit via tien g i n den ap suit bao hda [1, 2, 3,13] • Tinh phan di va bat ddng nhit cua d i u via mdng md Bach Hd vdi ty sd dau cao (193.7 m^/t) • He thdng nCrt ne via dau cd mdi lien he thuy lye cao va ty phan dp rong Idn so vdi hang loat via dau nCrt ne khae tren the gidi (21% theo nghien eCru thuy ddng lye [16] va 28% theo phan tich m i u Idi) • Sy hien dien cua ddng chay rdi he thdng nCrt ne - kenh dan ehinh nudi c i p cac gieng khoan tang mdng cung la mdt nhung yeu td lam gia tang them cudng dp hinh cac bao tCr he thdng nCrt ne [1, 2, 3, ] Trong bao cao nay, chung tdi trinh bay nhung nghien eCru ve dac diem bien ddi cac tinh chit thuy lye cua via dau mdng md Bach Hd, danh gia nguyen ly dieu ehinh trudng ap suit via tdi uu cua nd qua trinh khai thac nhim gia tang san lugng khai thac cung nhu he sd thu hdi dau II OAC OI^M BI^N l CAC TlNH QUA TRlNH KHAI CHAT THOY OONG Ll/C COA VIA DAU M O N G M BACH H6 TRONG THAC Nhung nghien cuu thyc dia eua tac gia ve dac diem bien ddi cac tinh chat thuy ddng lye eua via dau mdng md Bach Hd nhung nam g i n day [17,18,19] da ehUng td nhung xu the bien ddi sau: 89 Hdi thdo khoa hoc "Ndng cao he sdthu hdi ddu md Bqch Hd" - Ddi vdi cac gieng khoan ed ap suat via (Pv) va ap suit day (Pd) Idn han ap suit bao hda (Pbh) (ke ca nhung gieng cd ap suit day nhd hdn ap suit bao hda nhung ed gia tri dn dinh sudt qua trinh khai thac), thi he sd san pham, he sd thim cua mdi trudng nCrt ne (K2) va cac khdi matrix (KI) giai doan dau (Pv/Pbh > 1.55) cd xu the hai giam theo xu the giam cua ap suit via The nhung, bat dau tU ty suit giua Pv/Pbh dat gia tri tu 1.55 den 1.1 ta nhan thay cd sy gia tang dot bien cua cac he sd tren, dac biet la khoang Pv/Pbh = 1.35-1.1 Tai diem eye dai (Pv/Pbh = 1.25-1.2), he sd san pham Idn han gia tri ban dau eua nd khoang 30-50%, he sd thim cua mdi trudng nCrt ne thudng tang tU 2-3 lin, he sd thim cua khdi matrix ehi tang khoang 1.5-2 lin Khi Pv bat diu tien den Pbh (Pv/Pbh => 1,1-1.0), thi cac he sdtren bat diu giam dot ngpt Trong giai doan nay, Pd tien tdi Pbh thi gia tri he sd san pham giam rat manh (cd gie'ng he sd san pham bi giam den 30 % so vdi trudc dd - [18, 19]) Qua trinh tang, giam cac tinh chit thuy lye tren d nhieu gie'ng cdn mang tinh lap lai Cd nghla la, neu cd sy gia tang trd lai eua ap suit via thi chung cung tang trd lai va nguge lai (Hinh 1, 2) Do xu the bien ddi cac tinh chit thuy lye cua via diu mdng md Bach Hd so vdi gia tri Pv/Pbh hoan toan tuang ty vdi nhurng ket qua nghien cuu phdng thi nghiem cung nhu ngoai thyc dia ve hieu Crng phi can bing nhung nam gin day nen, theo chung tdi, sy gia tang dot bien cac tinh chit tren chu yeu la ed sy hinh cac vi bao tCr khi ap suit via tien dan den ap suit bao hda bdi chung gay hieu Crng "vdng bi khf vdi mCre dp manh d mdi trudng nCrt ne lam tang manh he sd thim K2 va muc dp vua phai d eae khdi matrix lam tang he sd thim KI Do dd ma he sd san pham cua cac gie'ng khoan cung tang theo Hinh 1: Bien ddi he sd san pham cac gie'ng mdng md Bach Hd so vdi gia tri Pv/Pbh (KI, K2 - cac gie'ng vdi Pd > Pbh: K3 - cac gie'ng vdi Pd < Pbh) Hinh 2: Bien ddi he sd san pham(Ksp), he sd thim mdi trudng nCrt ne (K2) va eae gia tri Pv/Pbh, Pd.'Pbh cua gieng XO qua trinh khai thac via diu mdng md Bach Hd 90 Hdi thdo khoa hoc "Ndng cao he sdthu hdi ddu md Bqch Hd" Bang Mpt sd thdng sd eua gieng XO mdng md Bach Hd qua trinh khai thac Thdi gian Pv/Pbh Skin Pd/Pbh K1,mD Ksp, m^/ng.MPa K2, mD 04.01.91 1.65 1.59 -5.61 563.8 29.9 2.1 02.08.91 1.53 1.47 - 506.2 - - 09.12.91 1.47 1.43 - 606.2 - - 16.03.92 1.47 1.43 -3,41 618.7 34.4 3.74 01.06.92 1.41 1.37 - 562.5 - - 05.09.92 1.36 1.33 - 631.2 - - 13.12.92 1.32 1.29 - 625.0 - - 02.02.93 1.3 1.25 - 662.5 - - 14.05.94 1.16 1.12 0.17 743.7 82.9 2.91 07.12.94 1.1 1.06 1.9 775.0 106.9 2.54 17.03.95 1.09 1.06 - 756.2 - - 27.07.96 1.06 1.04 - 693.7 - - 14.02.97 1.09 1.06 - 750.0 - - 17.04.99 1.13 1.09 1.6 731.2 93.1 3.42 12.11.99 1.08 1.05 -1.4 662.5 62.0 1.65 Khi Pv tien tdi Pbh (Pv= 1.1-1.0 Pbh) thi mat dp eae vi bao tCr gia tang dang ke mdi trudng rdng eua via lam cho eae kenh dan chat luu, khe nUt bi bit mdt phin dan den he sd thim eua via va duang nhien la he sd san pham cac gie'ng khoan bi giam dang ke Vi vay ma kich thudc Id hdng cua mdi trudng vi nCrt ne va cac khdi matrix nhd han so vdi kich thudc Id hdng eua he thdng nCrt ne cua via dau cho nen thdi diem bat diu gia tang manh cung nhu bat dau suy giam he sd thim cua nd KI (Pv = 1.55-1.2 Pbh) cung den sdm han so vdi he sd thim eua mdi trudng nUt ne K2 (Pv = 1.45-1.1 Pbh)-(Hinh 3) K1,md K2, md (> ^-^ 100 • • K2 OKI 90 • 80 • • • \p • ftT'^ 40 • • 2.5 •^n 30 • 09 • 3.5 cr/ 50 • • • 4.5 70 • 60 • • 5.5 1.1 1.2 1.3 1.4 1.5 1.6 • 1.7 p,-/p(,h Hinh 3: Mdng md Bach Hd - gieng XO Bien ddi he sd thim eua mdi trudng nut ne (K2) va eua khdi matrix phu thudc vao gia tri Pv/Pbh He sd tham cua cac khdi matrix KI cd gia tri cao nhat vdi Pv = 1.4-1.25 Pbh, cdn he sd tham eua mdi trudng nut ne K2 dat gia tri cao nhit vdi Pv = 1.25-1.2 Pbh Day la mdt ket luan quan trpng cho phep chung tdi de xuit kha nang dieu chinh qua trinh khai thac via diu bang trudng ap suit via tdi uu nham gia tang san luang khai thac cac gie'ng khoan ma khdng cin chi phi phat sinh dang ke nao 91 Hdi thdo khoa hoc "Ndng cao he sdthu hdi ddu md Bqch Ho" III DUY TRl T R I / O N G A P S U A T V I A T | L/U T R O N G Q U A TRlNH KHAI T H A C V I A DAU MONG M6 BACH H NHAM NANG CAO SAN SAN LI/ONG KHAI THAC VA HE s6 THU H6I DAU Ket qua nghien cdru a phan tren cho phep chung tdi dua mdt sd kien nghi ve tri trudng ap suit via tdi uu cho via dau mdng md Bach Hd qua trinh khai thac nhim nang cao san lugng khai thac cac gie'ng khoan cung nhu he sd thu hdi dau cua nd, cu the la: • Oe phat huy tdi da lgi ich cua hieu Crng phi can bang can tri trudng ap suit via cua vung nudi cip cac gieng khai thac cua via dau tmng binh a mCre 1.2-1.25 Pbh Vi kha nang luu thdng ap suit via dau a khdi trung tam rat tdt va vung nudi cap cac gieng khoan cd chieu sau tU 3050 den 3850 m, nen can phai tri ap suat via tai chieu sau 3050 m bang 1.05-1.1 Pbh (tdt nhit la 1.1 Pbh) de dat dugc he sd san pham cd nghla la san lugng khai thac Idn nhit cua cac gie'ng khai thac Khi dd ap suat via trung binh cua toan bd vung nudi cap cac gie'ng khai thac se bing 1.2-1.25 Pbh va ap suit via tai chieu sau 3850m se bang 1.4-1.45 Pbh Tuy nhien, de dat dugc he sd tham cao nhit cho mdi trudng vi nCrt ne va eae khdi matrix cd nghla la dat dugc he so thu hdi dau cao nhat cho mdi trudng (mdi trudng chiem tru lugng chu yeu eua via diu) thi cin phai tri ap suat via tmng binh cua vung nudi cap cac gieng khai thac bang 1.4-1.25 Pbh tCre la tri ap suit via tai chieu sau 3050 m bang 1.25-1.1 Pbh Ngoai ra, theo ket qua nghien ciru thyc dia tai via diu mdng md Bach Hd (Hinh 4) va phdng thi nghiem [1, 2, ] thi viec dieu chinh trudng ap suit via tdi uu cho via diu se cd hieu qua han nua neu ap suit via cua nd tai 3050m dugc giam vdi tdc dp cham tU 1.1 Pbh xudng cdn 1.05 Pbh sau dd lai dugc tang nhanh len mCrc 1.1 Pbh vi dd hieu ung gay xung ap suit se lam gia tang cudng dp tao eae vi bao tCr din den eae tinh chat thuy dpng lye cua mdi tmdng nCrt ne va matrix cung dugc cai thien lam gia tang cudng dp day diu mao dan tCJ mdi tmdng matrix vao he thdng nCrt ne ma ket qua la he sd thu hdi diu cua mdi trudng matrix cd nghla la toan via dugc gia tang dang ke Trong trudng hgp nay, san lugng khai thac cac gieng khoan cung tang theo dp tham cua he thong nCrt ne cung dugc gia tang dang ke nhd sy gia tang cudng dp tao cac vi bao tCr 370 360 -O—QB56 -6—QB29 -•—QCIO ^8 330 320 310 300 -O -KHflKocxeM - M.: HayKa, 1975 AjiCKcaHiipoB K).A riysbipbKOBbie KaMepbi - rocaxoMHSziax M.: 1969 XeHyop.!! A OxpHuaxejibHoe jxasnenHQ B >KM/],KOCX51X: KaK HX sacxaBMXb c.ay>KHXb He.noBeKy? y O H 1972.x 108, Bbin.2 Saberski R.H., Gates C.W Jet Propulsion, 25(2), 67(1962) 10 Bankoff S.G Trans ASME, 79(4), 735(1957), S 80 11 Griffith P., Wallis Y Chem Eng Progr Symp Series, 56(90), 49(1960) 12 Clark H B., Strenge P.S., Westwater Y.W Chem Eng Progr Symp Series, 55(29), 103(1959) 13 BeJiMeB O r 3KcnepMMeHxa.nbHoe MCCJieAOBaHMe KHHexHKM 4)a30Boro nepexcaa - JXAH A3ep5.ccp, xoM XI, Nil, 1984, c 34-37 14 MaMCAOB K).r M zipyrHe Onbix pa3pa5oxKH MecxopoKAeHHJi MnxHUjap-/], KHGHJI C Hayn rpyjXOB EBponeHCKoro CMMno3nyMa no yBe.nHHeHHfo Hec|}xeoxAaHH n.nacxoB FaararojiaHAMfl, 1997r 15 Phung Dinh Thyc va nnk Cdng nghe va ky thuat khai thac dau Nha xuit ban giao due Ha Ndi 1999 16 Trin Le Ddng, Mai Van Du Cac dac tinh thim chua dac trung cua than dau mdng md Bach Hd qua phan tich tai lieu khao sat gie'ng khoan Hpi nghi KHCN dau - Ha Ndi nam 2000 17 HaH Jle JXoHv MaR BaH 3bi npoMbicnoBbie Hccne/ioBaHHJi HepaBHOBCCHbix 3(})(|)eKX0B B npouecce paspaGoxKH He(})xera30Bbix Mecxopo>K;ieHMM - AsepG H XO3-BO, N^l-S, 2000 - c 47-52 18 Cao My Lgi, Mai Van Du Xu the bien ddi he sd san pham cac gie'ng tang mdng md Bach Hd qua trinh khai thac Hdi nghi KHCN diu khi- Ha Npi nam 2000 19 Phung Dinh Thyc, Mai Van Du Kha nang dieu ehinh qua trinh khai thac via diu mdng md Bach Hd qua nghien eUu dac diem bien ddi cac dac tinh thuy dpng lye hpc Hpi nghi KH ky niem 20 nam lap XNLD Vietsovpetro va khai thac tin diu thU 100 trieu - Vung Tau nam 2001 94 ... thdo khoa hoc "Ndng cao he sdthu hdi ddu md Bqch Ho" III DUY TRl T R I / O N G A P S U A T V I A T | L/U T R O N G Q U A TRlNH KHAI T H A C V I A DAU MONG M6 BACH H NHAM NANG CAO SAN SAN LI/ONG... eua khdi matrix phu thudc vao gia tri Pv/Pbh He sd tham cua cac khdi matrix KI cd gia tri cao nhat vdi Pv = 1.4-1.25 Pbh, cdn he sd tham eua mdi trudng nut ne K2 dat gia tri cao nhit vdi Pv = 1.25-1.2... bang 1.4-1.45 Pbh Tuy nhien, de dat dugc he sd tham cao nhit cho mdi trudng vi nCrt ne va eae khdi matrix cd nghla la dat dugc he so thu hdi dau cao nhat cho mdi trudng (mdi trudng chiem tru lugng