Tap chi KHKT Mo - Bia chat, so 31, 7120 'j^
PHAN TICH DAC TRUTVG KHAI THAC DAUTANG MIOXF MO BACH HO
PHAM Dtlrc THANG, NGUYEN VAN MINH Tap doan Ddu khi Viet Nam
TRAN DINH KIEN, Tnrang Dgi hoc Mo - Dia chdt
Tom tat: Tdng Mioxen hg cd cau tn'ic khd phirc tgp vd la mot trong nhung thdn ddu khai thdc chinh cua mo Bgch Ho. Tuy nhien. ket qua khai thdc tdng Mioxen hg mo Bgch Ho cho thdy via dang trong giai dogn khai thdc cudi ciing. sd lirang gieng khai thdc da khoan xong hodn toan vd do ngdp nude trung binh toan ddi tirgng Id 71%. He sd thu hdi ddu cudi ciing theo "Sa do thiet ke cdng nghe khai thdc vd xdy dung mo Bgch Ho " nam 2008 cho toan thdn ddu Id 31%. tiraOOSEg dirang 6144 trieti tdn. Lirang ddu dir du kien cdn Igi khoang 136''5 trieu tdn. Nhu vay, lirang ddu cdn Igi trong via la rdt lan vd do do cdn phai trien khai ngay viec nghien cini. dp dung cdc phuong phdp toi irii hod khai thdc de tan thu nguon tai nguyen ndy.
Bdi bcio ndy trinh bay cdc ket qua nghien ciru vd phdn tich nhung dgc trung ndng lugng via citing nhu lich sir khai thdc cua thdn ddu neu tren. Ket qud ndy se giiip chiing la xdc dinh cdc nguyen nhdn lam suy giam sdn lirang. tir do dua ra cdc bien phdp nham dieu chinh vd toi ini hod qud trinh thiet ke, khai thdc cd hieu qud ddu thiigc doi tirgng cdt ket Mioxen hg md Bgch Ho.
37, 42 va 45 cd gia trj trung binh la 28,8 MPa khi quy ddi ve do sau tuyet ddi-2810 m (ranh gidi quy udc ciia bien dudi bao hda dau) [5], Ap suat via ban dau cua than dau Mioxen ha d Vdm Bac do tai cac gieng rieng re (79, 98, 130, 136, 202) dugc chap nhan la 29,3 MPa (chuyen doi ve do sau tuyet ddi - 2971m, ranh gidi quy udc bag hda dau.
1. Tong quan dieu kien dja chat va khai thac than dau Mioxen mo Bach Ho
/. /. Khdi qudt ve dac trung dia chat - dja vat ly ciia tdng Mioxen ha
Phuc he Mioxen ha thudc diep Bach Hd va phat trien hau nhu tren toan dien tich ciia md vdi chieu sau the nam tii' 2759 - 2998 m dudi muc nude bien [1.2]. Cac tang san pham cua phirc he tinh tii' tren xudng dudi gdm cac tang 23. 24, 25, 26. 27 vdi mu'c do san pham cao cua chiing dugc quan sat thay d vdm Bac va vdm Trung tam. Cac tang san pham nay dugc gidi han d tren va dudi bdi cac tang phan xa dja chan lan lugt la SH-5 va SH-7. Tang phan .xa dau tien dugc gan vdi ndc via ciia tang san pham 23. tang phan xa thu' hai la mat bat chinh hgp Mio.xen ha - Oligoxen tren. Dau dat tru' lugng cdng nghiep ciia phii'c he dugc chung minh vao nam 1974 bang ket qua thir GK.BH-1 o vdm Trung tam cua cau tao. Hien tai. chi cd tang 23 la ddi tugng dang dugc khai thae [3.4].
Cot dia tang tdng hgp ciia phan lat cat chira san pham ciia md Bach Hd dugc md ta tren hinh I.
Sd lieu ap suat via ban dau ciia tang Mio.xen ha a \ dm Trung tam do d cac gieng 1, 22. 27,
Nhiet do tu nhien ciia than dau Mioxen ha do bang nhiet ke do sau cd do chinh xac cao tai cac phan ngung tre ciia than gieng nam phia dudi khoang lam viec trong cac gilng khai thac va bom ep sau la 80-1 10 "C. Gradient dia nhiet trong khoang tii' 1800 - 3600 m la 3,5 "C/IOO m. Do rong ciia tang san pham thay ddi tii' 0- 33.5 %, trung binh la 17,7%.
Do tham: cac kit qua phan tich mlu loi trong phdng thi nghiem va cac nghien cuu thiiy dong luc cho thay, ham thuc nghiem va quan he giira do rdng vdi do tham trong hai trudng hgp la ddng dang [6].
Ket qua thdng ke cho thay.
ludi thay ddi tir 0,5 mD - 1650 l a 2 3 9 m D .
. tham ciia 6
^- trung binh
lw6M.g<ti
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S ^ kft, b4c k k v^ c& k#t xen ke.Tr^t ddi thudc ufing sing ngiii ho, i^m l^y yii.i:i4n nAng.
Trirolich thuoc ti/ong ddla, song ngot, ho, J i m ^y va Dji'n nor^.
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Hinh 1. Cdt dia tang tdng hgp san pham md Bach Hd
Dg bao hda dau ban dau dugc tinh toan thdng qua sii' dung dudng cong tham pha va duong cong ap suat mao din, phii hgp vdi gia tri bao hda ban dau trong tinh toan tru lugng theo tirng tang san pham va theo tirng khdi. Do trong cac tang san pham khdng tdn tai mu khi nen do bao hda nude dugc tinh bang 1 (do bao hda dau ban dlu). Dac trung tinh chat thlm chiia ciia cac tang san phSm duoc gidi thieu trong bang 1.
Phuong phap
Bang 1. Dac trung tinh chat tham chira cac tang san pham Cac chi sd Do tham.
mD
Do rdng.
p.d.v
Do bao hoa dau ban dau,
p.d.v Tang 23 - Vdm trung tam
Phan tich mau loi Dja vat ly
gi4ng khoan
Gia trj trung binh Khoang bien ddi Gia trj trung binh Khoang bien ddi
276 2,5-2500
0,195 0,14-0,28
0,182 0,14-0.25
0,506 0,35-0,71
Do br n''
0,47
" 0 2 0 ^ 0 8 0 ^ 0,494 0.29-0,65 Tang 23 - Vdm bac
Phan tich mau loi Dia vat ly
gieng khoan
Gia tri trung binh Khoang bien ddi Gia tri trung binh Khoang bien ddi
120 2,8-652
0,19 0,14-0,24
0,189 0,14-0.25
0,522 0,35-0,84
0.45 0,28-0,75
0,478 0,16-0,65 Cac chi sd dac trung ve tinh bat ddng nhat cac tang san pham thudc tang Mioxen ha dugc the hien tren Bang 2.
Da chira tram tich md Bach Hd cd cac dac diem chung ciia dang da chira cat - set vdi do rdng giira hat. Ba thanh phan ca ban cua dang da chua nay bao gdm phan khung da, xi mang gan ket va chat luu.
Bang 2. Cac chi sd dac trung ve tinh bat ddng nhat cac tang san pham Mioxen ha Tang san
pham
23 24 24 24 24 24 24 24 24 24 25 25 26 27 27
Ky hieu than dau
1 1 2 3 4 5 6 7 8 9 1 2 1 1 2
So gieng khoan dung vao
tinh 156 1 12 7 2 1 2 3 2 1 2
1 2 4 1
He sd cat, p.d.v Gia trj
trung binh 0,32 0,06 0,15 0,30 0,24 0,63 0,37 0,26 0,20 0,56 0,25 0,11 0,26 0,34 0,23
He so bien thien 0,53 0,63 0,31 0,02 0,43 0,62 0,07 0,64 0,10 0,83
He sd phan Idp, p.d.v Gia trj
trung binh 3,25 1,00 3,08 2,57 3,00 5,00 4,00 3,33 1,00 6,00 2,00 2,00 2,20 5,00
He sd bien thien
0,60 0,47 0,49 0,47 0,71 0,17 0,00 0,71 0,99
~
He sd gian doan
16,36 Tang 24 cd 8 than
dau trong pham vi dien tich
Bang 3. Tinh chat cua chat luu via than dau tang Mioxen Cac chi sd
Ap suat bao hoa. MPa Ham lugng khi. m^T He sd the tich
Do nhdt ciia dau trong dieu kien via, MPa *s Ti trgng cua dau trong dieu kien via, kg/m^
Ti trgng cua dau da tach khi, kg/m"*
Ti trgng ciia khi trong dieu kien via. kg/m"
Ti trgng ciia nude trong dieu kien via. kg/m"
He sd the tich ciia nude
Vdm Bac 20,42
141,4 1,399 1,074 710,2 865,3 1,100 1005,3 1,0453
ha
Vdm Tr. t.
14,60 99.9 1,312 1.989 793.5 864,0
- - 1,0442
Phan bd gia trj cac tham sd chua (0,So) cac tang san pham Mioxen ha (theo DVLGK) dugc trinh bay trong hinh 2.
V 6 M TRUNG T A M
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So
V6M BAC
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So
Hinh 2. Phan bd gia trj cac tham sd chua (0,So) cac tang san phdm Mioxen ha (theo DVLGK)
7.2 Dac trung ndng heffng, dp suat via trong viing khai thdc vd ham ep
1.2.1. Vdm Trung tdm
.\p suat \ la ban dau cua than dau d vdm Trung tam dugc do vao giai doan dau khai thac than dau va chuyen ve vi tri ranh gidi dau nude (RGDN) qui udc ban dau chieu sau tu\et ddi - 2821 m la 28.1 MPa. Theo ddng thai bien ddi ap suat via trong qua trinh khai thac. than dau dugc chia ra lam hai viing rieng biet [2,7].
Viing phia Tay cua than dau dugc dac trung bdi su lien thdng kem vdi viing ria, vdi su gia tang thu hdi dau. ap suat via cd xu hudng giam ciing vdi qua trinh khai thac cho den khi bat dau bam ep nude vao 7/1987. Viec bom ep nude vao via. mac dii vln tilp tuc dua them gieng khai thac vao hoat ddng va day manh thu hdi, nhung ap suat via da tang dan va dugc duy tri d
mire 25-30 MPa. He sd bii khai thac va he sd bii khai thac cdng don tir n.
vugt qua I00°/'o. dan den ap siiai ;'• •-' khu vuc rieno biet ciia than dau ' ^"
Ji
da . sd - suat via ban dau. Tu\ nhien d khu , - . -' '^^'^ '''•'^
than dau. ap suat via bi giam dang ke xudng toi 12 MPa. dilu nay chirng td mdi Hen thdng thuy luc rat kem cua khu vuc nay vdi viing khai thac va bom ep chinh ciia than dau.
Viing phia Ddng ciia than dau cd su hd trg cua ap luc nude ria. Tuy nhien nang lugng ciia nude ria la khdng du Idn, vi ap suat via tai cac gilng khoan giam xudng cdn 19,8 - 20,7 MPa, tuy cdn cao hon ap suat bao hda (14.6 MPa).
nhung da thap han gia trj ban dau (28,1 MPa).
Dong thai cua ap suSt via cac gieng vdm Trung tam duoc dua ra tren hinh 3.
03.87 03.88 0 3 8! 03.92 03.93 0 3 94 03.95 03.96 03.97 03.90 03.99 0 3 0 0 0 3 01 03.02 03.03 03.04 03.05 03,06 03,07
Hinh 3. Ddng thai ap suat via cac gieng khoan Mioxen ha vdm Trung tam 7.2.2 Vdm Bac
Ap suat via ban dau ciia than dau d Vdm Bac. dugc do vao giai doan dau cua qua trinh khai thac va chuNen ve vj tri RGDN quy udc ban dau -2971m la 29,6 Mpa [4]. Than dau dugc chia ra lam 3 viing: 1. 2 va 3 dua tren muc do anh hudng khac nhau cua ap luc bom ep va ap luc nude ria ddi vdi qua trinh khai thac.
Viing thu' nhat ed cac gieng khoan 63. 69, 70. 71. 74. 79. 83, 87, 93, 98, 117,130 bj tach biet vdi viing nudi d ria bdi cac diit gay kien tao
va cac ddi khdng ed viing chira dau cue bd.
Trong giai doan khai thac ban dau. ap suat via giam manh. Viec bo'in ep nude dugc bat diu tir 4-1988 da giiip ap suat via hdi phuc va dn djnh d muc 26-28 MPa. Vao cudi nam 1996, sau khi ngiing bom ep, than dau dugc tiep tuc khai thac d chi do suy thoai. Ap suat via dugc do ddng loat tai cac gieng vao thang 09 la 25-27 MPa. Ap suit via do dugc troi ni 2002 d mot sd gilng khoan rieng biet 0 xudng cdn 20.5-20,7 MPa (ap suit bac 20 4
MPa). Thang 10-2002. viec bom ep nude dugc khdi phuc tro lai cho phep dn dinh dugc phan nao ap suat via trong viing khai thac.
Viing thir hai cd cac gieng khoan 82, 86, 121. 136 dien ra vdi su tac ddng ciia ap luc nude ria. San lugng khai thac tap trung d cac
gieng nam d phan trung tam ciia viing na}. noi ap suat via den cudi giai dgan khai thac da giam xudng chi cdn 27 MPa. Cho den naj. hau het cac gieng khai thac da bi bd do ngap nude cao.
Ap suat via den nam 1999 chi cdn 24,7 MPa.
'? 401
03/66 03/B7 03'8B 03/66 03/60 03/61 03/62 03/63 03/94 03/9S 03/66 03/97 03/98 03/96 03/00 03/01 03/02 03/03 03/04 03/05 03/06 03/07
— • — 6 3 . .^ 121
- • — 6 9 130 —
70 136
• M 71 — w — 7 9 — . — 82 — . — 86 87 -
^ 145 — ^ - 2 0 2 • 705 — * — 7 1 0 — x — 8 0 6 — _.... 89
»—815
93 95 _»-_816 — , — 617
98 ..- 101 .*. . 117i
— — 6 1 8 — — 8 2 0 — • — 9 1 7 !
Hinh 4. Ddng thai ap suat via cac gieng khoan Mioxen ha Vdm Bac Viing thir ba cd cac gieng 95. 202. 804.
806. 815, 816, 817, 818, 820, 917, tir nam 1987-1994 chi cd I gieng dugc dua vao khai thac. Trong giai doan nay ap suat via giam khdng dang ke va cdn la 25,7 MPa vao cudi nam 1994. Su gia tang khai thac dau sau dd da lam cho ap suat via giam manh. Ap suat via do vao thang 5-1996 quy ve vi tri RGDN ban dau (chilu sau tuyet ddi -2971m) la 21.8 MPa. Bom ep nude vao thdi ky nay dugc bat dau tii' thang 5-1996 cho phep ap suat via dugc nang len va dn dinh d cac giai doan khai thac tiep theo. Ap suat via do vao thang 8-2002, thay ddi trong khoang 24.1 - 24.5 MPa, gia tri nay ciia ap suat via cho phep duy tri luu lugng cao trong cac gieng khai thac va cd 2 gieng dang dugc tiep tuc khai thac d che do tu phun [8]. Ddng thai ap suat via ciia cac gieng d Vdm Bac dugc the hien tren Hinh 4.
2. Phan tich thuc trang khai thac va hieu qua ciia viec day dau bang nuoc tang Mioxen ha mo Bach Ho
Tdng quy gieng d tang Mioxen ha cho den ngay 01.9.2009 la 37 gieng, trong dd quy gieng khai thac la 29 gieng: 3 gieng khai thac tu phun, 26 gieng khai thac gasliit, 2 gieng khdng hoat ddng; quy gieng bom ep cd 8 gieng, trong dd ca 8 gieng deu hoat ddng [9]. So dd phan bd cac gieng khoan d tang Mioxen ha dugc md ta tren hinh 5.
Than dau tang Mioxen ha cd cau tao dang vdm dugc ehia ra thanh 2 vdm: Vdm Trung tam va Vdm Bac.
Vdm Trung Tdm:
Quy gieng khai thae la 12 gieng. trong dd cd 11 gieng hoat ddng. Luu lugng dau trung binh hien thai ciia vdm Trung tam la 16.1 tan/ng.d. vdi do ngap nude san pham trung binh la 53,70 %. Chi sd khi dau hien thai bien ddi tii' 80 din 4000 m^/tan.
Quy gieng bom ep hoat ddng cd ba gieng (22, 37 va 905) cd do tilp nhan khoang 223-243 m7ng.d. vdi ap suat bom 2,4 - 8.1 MPa.
M* Bacb Ho
SO B O F H A N B O CAC GIENG K H O . \ N T A N G MIOXEN DVOl
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Hinh 5. Sa do phan bd cac gieng khoan tang Mioxen ha Than dau Vdm Trung tam dugc dua vao
khai thac nam 1986. Viec bom ep nude de duy tri ap suat via dugc bat dau vao nam 1987. San lugng dau cao nhat dat 120 ngan tan vao nam 1988. Tiep theo dd la giai doan suy giam va chi cdn 30 ngan tan vao nam 2000 do do ngap nude san pham tang va cac gieng ngiing phun. Trong nam 2001. san lugng khai thac dau da tang len 52 ngan tan nhd viec dua vao khai thac 1 gieng khoan mdi \a ket qua ciia viec tien hanh xu ly viing can da\ gieng nen do ngap nude san pham siiam tir 43.7 % xudna cdn 33,1 %, trong nam
2002 san lugng dau khai thae la 48 ngan tan vdi do ngap nude sart pham d muc 32,1 %.
Trong giai doan 1987-1997, nude da tien hanh bom ep vao via bang 1 gieng bom ep vdi luu lugng til' 27 den 128 ng. m7nam, nam 1997 dua tiep I gieng vao bom ep. Viec bom ep nude lam dn dinh khai thac va lam tang ap suat via.
Khdi lugng bom ep trong ba nam cuoi giam di do ap suat via ciia than dau da tang bang ap suit thuy tmh. Hinh 6 the hien ddng thai khai thac tai tang Mioxen ha md Bach Hd.
ill III
^^ %. '$
1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 Nam
- Dp ng^p nuac Irung binh —*~ H^ so thu hoi dau -m— Quy gieng khai thac den het nSin - L.u^mg nuoc bom ep hang nSm - San liriyng khai thac dau hang nSm
Hinh 6. Ddng thai khai thac tai tang Mioxen ha md Bach Hd Nude xuat hien trong san pham sau ba nam
ke tir khi bat dau dua vao khai thac vdi muc do ngap nude da la 19,2% vao nam 1990 va giu' dn djnh cho den nam 1993, tiep sau dd do ngap nude tang trd lai len den 43,7 % vao nam 2000 sau khi chuyen hang loat gieng sang khai thac bang gasliit.
Qua trinh khai thac canh Ddng ciia Vdm Trung tam da cho thay cd sir cd mat ciia ap luc nude ria nhung miie do tac ddng ciia nd cdn
>eu. khdng dii de ngan chan su suy giam ciia ap suat via trong viing khai thac.
Tinh den ngay 01.08.2007, tir than dau vdm Trung tam da thu hdi 1204.82 ngan tan dau.
than dau dang trong giai doan khai thac cudi vdi chi sd nude dau cdng ddn la 0.45 mVtan. Tdng U'ir lugng dau vdm Trung tam la 8050 ngan tan va he sd thu hdi dau la 0.15. Than dau cua ddi tugng khai thac nay dugc chia ra lam 2 viing.
Mire do thu hdi trir lugng dau d cac viing n;i_\ nhu sau:
- Viing Ta\' nam d phia tay ciiadut ga\ theo ui\en gieng 27- gieng 45 cd tdng tru lugng dau la 3.^52.2 ngan tan. Tdng cdng tir cac tkng san pham da khai thac dugc 683.06 ngan tan dau.
iicsdthuhcMdaulaO.I9.
- Viing Ddng nam d phia ddng ciia dirt gay theo tuyen gieng 27- gieng 45 dugc khai thac bang che do ap nude tu nhien. Tdng trir lugng dau ciia viing nay la 4497.5 ngan tan. Tir viing nay da khai thac dugc 521.76 ngan tan dau vdi he sd thu hdi dau dat 0.12.
Vdm Bac:
Quy gieng khai thac la 17 gieng. trong dd cd 16 gieng hoat ddng. Luu lugng dau trung binh la 17,8 tan/ng.d. vdi do ngap nude san pham trung binh la 79,3 %. Chi sd khi dau trung binh la 371 m Mn, cao hon ham lugng khi hoa tan trong dau via, chiing td ap suat via da giam cue bd xudng dudi ap suat bao hoa.
Do tiep nhan ciia cac gieng bom ep dang hoat ddng bien ddi trong khoang tii' 200 den 250 m'Vng.d. vdi ap suat bam ep len den 25 MPa.
Than dau Vdm Bac dugc chia ra thanh cac khdi va bat dau khai thac vao thang 11.1986.
Mire khai thac dau dat 187 ngan tan vao nam 1989. Sau dd, san lugng khai thac dau giam kha nhanh xudng cdn 88 ngan tan va 93 ngan tan tuong irng vao cac nam 1990 va 1991 do do ngap nude ciia san pham tang va hang loat gieng khai thac ngirng phun.
Nhd dua them gieng mdi vao khai thac \a
chu\en gieng ngirng phun sang khai thac bang phuong phap co' hgc nen den trudc nam 1995.
san lugng khai thac da dat muc 170-120 ngan tan. Trong cac nam 1995-1997, san lugng khai thac dau tang len den 250-265 ngan tan nhd dua vao hoat ddng them 5 gieng mdi cd luu lugng Idn. Trong nam 1998. san lugng khai thae dau giam .xudng cdn 176 ngan tan do do ngap nude cua san pham tang va cac gieng khai thac ngirng phun.
Giai doan 1999-2002 dac trung bdi su gia tang san lugng khai thac dau len den 276 ngan tan. mire khai thac dau cao nhat dat dugc vao nam 1999 va sau dd giam tii' tii' xudng cdn 152 ngan tin vao nam 2002. Trong khoang giai doan nay da dua them cac gieng mdi vao hoat ddng. dua gieng ngiing phun sang khai thac bang gaslift va tien hanh xu ly viing can day gieng.
Nam 1988 bat dau bom ep nude vao tai 3 gilng. Do khdi lugng nude bom ep hang nam khdng deu va viec dua gieng vao khai thac khdng ciing luc nen nhip do thu hdi chat luu ciia via theo cac khdi cua than dau la khac nhau.
Tuy nhien. viec bom ep nude da giup duy tri ap suat via trong viing thu hdi cao hon ap suat bao hoa. Khdi lugng nude bom ep cao nhat dat 306 ng.m^ vao nam 1994. cdn cac nam khac thay ddi tir 110-300 ng.m^/nam.
He sd bii khai thac bang bom ep khac nhau a cac khdi va trung binh la 40,6 %. Nude xuat hien trong san pham vao nam khai thac thu' hai (1987) va do ngap nude san pham da len den 37.6 % vao nam 1990. Sau dd, tdc do tang do ngap nude san pham cham lai nhd khoan va dua them cac gieng mdi vao hoat ddng tai cac viing khac nhau cua than dau. Den nay, tat ca cac
2iln2 khai thac diu da bi naap nude \ ^'^
khac nhau \ a trung binh vao nam 200 ^°- Tinh din ngay 01.8.2007. tir tha: Vdm Bac da thu hdi"3457.498 ngan tan d a than dau dang trong giai doan su) giam san lugng khai thac vdi chi sd nude dau cdng ddn la 0.96 m^tan [11]. Than dau dugc khai thac d che do cd du\ tri ap suat via bang bom ep nude ciing vdi tac ddng dang kl ciia ap luc nude ria d mot sd khu vuc rieng le va he sd thu hdi dau la 0.31.
Tdm lai. mixc khai thac dau hang nam cua than dau tang Mioxen ha thay ddi trong khoang rdng tir 126 din 310 ng.t./nam. Miic khai thac dau cao nhat dat dugc vao nam 1999 (nam khai thac thir 14). nhd viec tiln hanh dan day mang ludi gilng khoan bang each khoan gieng mdi ciing vdi viec chuyen cac gieng tii' cac ddi tugng khac din, ap dung phuong phap khai thac gaslift va thuc hien cac giai phap khai thac tang cudng.
Din ngay 01.08.2007, tang Mioxen h^ tdng cdng da thu hdi dugc 4662,32 ngan tan dau, he sd thu hdi dau la 0,24 va than dau dang trong giai doan suy giam san lugng. Than dau dugc khai thae bang bom ep nude cd tac ddng ciia nude ria vdi mire do khac nhau tai cac viing khac nhau. Tdng san lugng cdng ddn tdi thdi dilm 01.08.2009 la 5011 ngan tan dlu va 0.993 ty m^. do ngap nude trung binh la 72,3%. he so bii nam 2009 la 79,5%.
Vdi su cd mat ciia nude ria d hau het cac khu vuc ciia ddi tugng, tuy nhien muc do anh hudng khdng Idn va khdng ddng deu, ciing vdi su lien thdng thuy lire kem va khdi lugng nude bom ep vao via cung khdng ddng deu cho nen he sd thu hdi dau d cac vdm ehenh lech nhau kha Idn (xem bang 4).
Bang 4. Tinh trang khai thac dau ciia tang Mioxen
\ \ ^ Cac chi sd
Ddi tugng \ . ^
Mioxen ha Vdm Trung tam Mioxen ha Vdm bac
Toan bd Mioxen ha
San lugng dau khai
thac cdng ddn, ng.t.
1204,8 3457.5 4662,3
San lugng nude khai thac cdng
ddn.
ng.m^.
537.1 3324.2 3861.3
Khdi lugng nude bom
ep cdng ddn. ng.m .
2030.3 4892.9 7013.2
ha den ngay He sd bii khai thae cdng ddn.
%
81,55 58,26 63,51
01-08-2007 He sd thu
hdi dau.
p. d. V.
0.15 0.31 ( '
Tren bang 4, ta thay sir khac biet rd ret giira Vdm Bac va Vdm Trung tam, tir dd chi ra rang can tap trung uu tien cac giai phap nang cao he sd thu hdi dau hon cho vdm bac, nai ma trir lugng cung chien gan 60 % so vdi tdng sd ma he sd thu hdi dau da dat 31 %, nghTa la khdng the tan thu bang each bd tri them gieng mdi cho viing nay.
Gia trj trung binh trgng sd theo trir lugng ciia he sd thu hdi (HSTH) diu ciia tang Mioxen ha thay doi tii' 0,156 den 0,307 va cd gia trj trung binh la 0,237. Tdng tru lugng dia chat cua Mioxen ha la 28553 ngan tan dugc chap nhan diing trong thiet ke. Trong trudng hgp HSTH dau chap thuan la 0,237, tdng san lugng cdng ddn cua tang Mioxen ha la 6766 ngan tan, trong dd til' tang san pham 23 la 6406 ngan tan. Dudi day la bang tdng san lugng cdng ddn udc tinh tren co sd he thdng khai thac hien tai.
Bang 5. Tdng san lugng cgng ddn udc tinh tren ca sd he thdng khai thac hien tai (Mioxen ha) Tang san
pham
23 24 25, 26, 27
Tdng sd
Tru' lugng dia
chat (ng.t) 17084 2927 8542 28553
He sd thu hdi dau theo tinh
toan 0,3750 0,.0500 0,0250 0,2370
Tdng san lugng cdng
ddn udc tinh (ng.t)
6406 146 214 6766 3. Ket luan
Qua cac ket qua nghien cuu va phan tich dac trung nang lugng via, khai thac ddi tugng tang Mioxen ha md Bach Hd trong bai bao, ed the dua ra nhung ket luan sau:
- Tang chira cat ket Mioxen ha da dugc lam ro vdi cac dac trung dja chat, dia vat ly kha phirc tap va cd dac tinh chua kha tdt vdi do rdng trung binh la 17.7 % va do tham trung binh la 239 mD;
- Dac trung nang lugng va ap suat via cua ddi tugng tang Mioxen ha dugc dieu chinh kha dn dinh trong sudt qua trinh khai thae md vdi ap suat via trung binh ban dau la 28-29 MPa (nam 1986), mac dii he sd bii khdng dat 100% chirng
td cd su hoat ddng cua nude day (viing phia Ddng, Vdm Trung tam);
- Viec ap dung va bd sung cac gieng bom ep nude de duy tri ap suat via da dugc xem xet mot each cd hieu qua ngay tir dau qua trinh khai thac (7/1987), tuy nhien viec ap dung nay cdn han che ddi vdi cac viing khai thac va bom ep cd do lien thdng kem (viing phia Tay, Vdm Trung tam);
- Nude bat dau xuat hien trong san pham sau ba nam khai thac vdi do ngap nude la 19,2% vao nam 1990 va 43,7 % vao nam 2000, sau do tang dan cho den hien nay (72,3 %) lam giam san lugng khai thac;
- Viec dua gieng mdi vao khai thac, chuyen cac gieng ngiing tu phun sang khai thae gaslift, chuyen cac gieng tii' ddi tugng dudi len va xir ly viing can day gieng da gdp phan gia tang san lugng dau khai thac ciia ddi tugng nay vdi tdng san lugng cgng ddn tdi thdi diem 01.8.2009 la 5011 ngan tan dau;
- Tru' lugng dau chii yeu dugc thu hdi tii' tang san pham 23 la 6406 ngan tan. He sd thu hdi trung binh hien nay cho toan ddi tugng la 20,85 %.
TAI LIEU THAM KHAO
[1]. Hiing, N. M., 2004; Nghien ciru kha nang ung dung bom ep nude khi nude luan phien ddi vdi cac md dau Viet Nam, Bao cao tdng ket de tai, 2004.
[2]. Lake, L. W., 1989; Enhanced Oil Recovery, University of Texas, Austin, Texas, USA, Published by Prentuce-Hall, Inc, A Division of Simon & Schuster, Englewood Cliffs, New Jersey 07632.
[3]. PetroVietnam, 2003; Nang cao thu hdi dau cho md Bach Hd, Bao cao hdi nghi khoa hgc, Vietsovpetro, Vung Tau, Viet Nam. 2003.
[4]. Thang, P.D., Trung, N. H., 2007; Nghien CLi'u de xuat giai phap khai thac tan thu ddi tugng cat ket Mioxen ha, Oligoxen md Bach H6, 2007.
[5]. Trung, N. H., 1997; Nghien ciru kha nang ling dung phiic he Polymer de bam ep trong mdng nut ne tai cac gieng khoan d them luce dia Viet Nam nham nang cao he sd thu hdi dau
khi. Bao cao tdng ket de tai. Vien Dau Khi. Ha Ndi. Viet Nam. 1997.
[6]. Trung. N.H.. 2007; Giai phap gia tang san lugng khai thac \a nang cao he sd thu hdi dau d them luc dia Viet Nam- Hdi thao trien khai ke hoach khai thac dau khi nam 2007.
[7]. Vinh. N.X.. 2000: Nhirng ylu to anh hudng den tinh chat tham chira cua da luc nguyen Mioxen sdm-Oligo.xen be Cuu Long, Hdi nghj khoa hgc cdng nghe 2000: Nganh dau khi Viet Nam trudc thim thi kv 21, 2000.
:h iai vhai khai [8]. VSP. 2007; Trang thai khai thac r Hd. md Rdng tdi thai diem 10.01.0' phap nham dam bao hoan thanh ke ii thac 2007-Hdi thao triln khai ke h^
thac dau khi nam 2007.
[9]. VSP. 2009; Vietsovpetro va mot vai nghiem quan ly va dilu hanh khai thac md thao hdi nghi khoa hgc cdng nghe.
[10]. VSP. 2008; So dd thilt kl cdng nghe khai thac va xay dung md Bach Hd-Vietsovpetro, 2008.
kinh Hdi
SUMMARY
The characteristics of production of niiocene formation. Bach Ho field Pham Due Thang, Nguyen Van Minh, Vietnam Oil and Gas Group
Tran Dinh Kien,L''«/ve/-.s'/7i' of Mining and Geology
The Miocene formation has quite complex structure and it is one of main producers of the White Tiger field. However, the production life of this formation of the White Tiger field shown that it have been in the final declining phase, the number of well productions have finished drilling and the average of water cut is 7\%. The final oil recovery factor is 31%, equal to 6144 million tones for entire formation according to "Production engineering and construction scheme of the White Tiger field" in 2008. The residual oil in this formation is about 13675 million tones.
Therefore, the rest oil in this formation is very large and it needs to be carried out immediately the research and applying of the optimal produced methods for enhanced oil recovery of this resouces.
This paper presents the results of research and analying on the characteristics of energy and production of the above formation. These results also helped us to determine the reasons of production declining and then having methods to adjust and optimize the effective designing, production process for Miocene formation of the White Tiger field.
Ngudi phan bien: Hodng Dung
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