1036 Phan tich thi nghiem thii- ap suht cho mdng ran nut ciia md RatTgjDdng^
PHAN TICH THI NGHIEM THtT AP SUAT CHO MONG RAN NlTT CUA MO RANG DONG
Nguyin Hai Minh, Pham Huy Giao Hgc viin Cdng nghi Chdu A
TOM T A T
Md Rgng Ddng dugc phdt hiin vdo ndm 1995 vd hiin dang dugc khai thde. Viec ddnh gid cdc thdng sd do thdm, thdng sd skin, dnh hu&ng cua thi tich chdt luu trong thdnh giing vd van tdc thdm chdy tir cdc khdi matrix vdo nut ni, v.v. qua phdn tich sd lieu thi nghiim thu dp sudt la rdt quan trgng cho qudn ly via trong giai dogn phdt triin vd khai thac.
Bdo cdo ndy di cap din phuomg phdp so sdnh ducmg cong chudn vd du&ng cong khdo sdt, nhdm minh gidi sd lieu thir dp sudt trong mdng md Rgng Ddng. Md ngudn chuomg trinh bdng Fortran cua tdc gid Sabet (1991) da dugc cdi thiin phdt triin thdnh mdt chuong trinh m&i cd tin ggi la Wel_Frac, dung di tgo ra cdc du&ng cong chudn cho mdi trudmg mdt do rdng vd hai do rdng. Chuomg trinh Wel_Frac cd thi di ddng chgy trin cdc bd dich Fortran sdn cd trin thi trucmg hiin nay. Khi cdc dudng cong chudn dugc tgo ra vd trinh bdy du&i dgng tog do thu nguyen, viec so sdnh vi dd thi ducmg cong chudn vd du&ng khdo sdt da dugc hodn thdnh bdng sir dung phdn mim ve do thi Grapher. Quy trinh so sdnh ndy do Giao (2003) di xudt cho thir dp sudt giing bom cua nu&c ngdm.
Phuang phdp so sdnh dd thi trin mdy tinh cd thi dp dung cho cdc du&ng cong thi nghiim bom dp ciia cdc md ddu khi nhu da chirng minh trong bdo cdo ndy.
Hai tap sd lieu thir dp sudt cua mdng md Rgng Ddng da dugc phdn tich dua tren cdc du&ng cong chudn tgo b&i chuong trinh Wel_Frac dua trin quy trinh so sdnh dd thi du&ng cong da di cap & trin. Ba md hinh cua via nirt ne dd dugc thir cho md Rgng Ddng gdm md hinh ddng nhdt mdt do rdng, md hinh gid dn dmh hai do rdng vd md hinh khdng
dn dinh hai do rdng. Ldi minh gidi trung binh da dugc u&c tinh b&i chuang trinh Wel_Frac vd md hinh gid dn dinh hai do rdng dugc ddnh gid Id tdt nhdt.
KY HIEU
5 = He so thanh he, RB/STB
c, = Tdng do nen tai dilu kien ban diu, LtVm, psi"' h = Chieu day thanh he chiia diu, L, ft
/C = Do thim, L ^ m D P = Ap suat, m/Lt^, psi PD = Ap suat thir nguyen
PDU = Ap suat thanh gieng thir nguyen
P,,f= Ap suat chay vao thanh gieng, m/Lt^, psi
Tuygn tap bao cao Hdi nghj KHCN "30 nSm Dau khi Viet Nam: Co" hdi mdi, thach thuc mdi" 1037
Q = Luu lugng ddng chay, L^t, STB/D r = Ban kinh anh hudmg, L, ft
ro = Ban kinh anh hudng thii nguyen r,, = Ban kinh thanh gilng, L, ft iS* = He sd CO hgc Skin
t = Thdi gian, T, gid to = Thdi gian thii nguyen z = Bien Laplace
s = Sai sd minh giai trung binh, % )ji = Do nhdt dau, m/Lt, ep
(^ = Do rdng
Q = Thdng sd chiia trong niit ne
X = He sd dac trung cho cudng do ddng luu chay giiia hai mdi trudng nirt ne va khdi matrix
CHI SO DU'6l DONG D: Thii nguyen / Niitne
m: matrix w: Thanh gieng
GI61 THIEU
Cac md dau khi trong da mdng chiem 5 phan tram eua tdng trtr lugng dau khi tren the gidi. Phan cdn lai dugc tim thay trong da cat ket va da carbonat. Sd lugng md dau khi trong da mdng kha nhd, cd 35 md tren the gidi. Nhu mdt trudmg hgp dac biet, hau het cac md dau d phia Nam them luc dia Viet Nam khai thac tir mdng granit niit ne vdi chieu sau mdt vai km. Cac thdng sd cho md phdng via, khai thac va quan ly thudng dugc danh gia dua tren cac thdng sd thu dugc tir thir via, dia vat ly gieng khoan, v.v.. Trong pham vi bao cao nay cac tac gia tap trung vao phan tich thi nghiem bom ap bang phuong phap so sanh do thi, vdn la mdt phuang phap thdng dung va hiiu ich cho cae ky su cdng nghe md.
Muc dich nghien ciiu chinh la phat trien mdt phuong phap minh giai tien ich va re tien eho sd lieu thi nghiem thir chuyen ap suat eho via mdng niit ne va ap dung cho da mdng md Rang Ddng d Viet Nam (Hinh 1). Hai tap sd lieu thir chuyen ap ciia md Rang Ddng da dugc lira chgn eho phan tich. Luu y, ten gieng, vi tri toa do, v.v. da dugc thay ddi trong nghien cim vi ly do bao mat thdng tin.
1038 Phan tich thi nghiem thir ap suht cho mdng ran nut ciia md Rang Odng^
Hinh 1: Mo Rang Dong o phia Nam them luc dia Viet Nam
Barenblatt (1960) la ngudi dau tien da coi da niit ne tu nhien la cac khdi hop dugc phan chia bdi cac khdi matrix va nirt ne. Warren va Root (1963) chuyin hoa va biin ddi thanh edng phuong trinh ddng chay cho via mit ne dua tren cac gia thilt cua Barenblatt vdi khdi matrix va nirt ne, trong md hinh ciia hg mdi trudng niit ne tu nhien dugc dac trung bdi hai thdng sd, u\a&. (^ day u dugc dinh nghia la ty suat cua mdi trudmg niit ne vdi toan via va a la he sd dac trung cho cudng do ddng luu chay gitra hai mdi trudmg nirt ne va khdi matrix dugc tinh bang ty sd cua do tham khdi matrix va do thim nirt ne.
Phuomg trinh khuech tan eiia Warren va Root (1963) dudi dang thii nguyen dugc trinh bay nhu sau:
.dPn ol n
(1)
X"y^n tap bao cao Hpi nghj KHCN "30 n^m DSu khi Viet Nam: Co- hdi mdi, thach thuc mdi' 1039 O day: Po„, va PD/ la ap suit thir nguyen cua khdi matrix va nirt ne tuomg img; to la thdi gian thir nguyen; u la thdng sd chiia trong nirt ne va & la he so dac trung cho cudng do ddng luu chay giua hai mdi trudng nirt ne va khdi matrix.
Bourdet va Gringarten (1980) da biin ddi thanh cdng tap dudng cong chuan cho ddng chay xuyen tam, tdi gilng bang each gia thiet he sd anh hudmg thanh gieng va he sd skin la hing sd va bing 0 eho mdi trudng hai do rdng vdi nghiem giai tich sau:
K, (r,, 4^(7) ) + S4W(7)K, (4Wl^))
Po(^) =
z{4^f7)K, (4^fT^)) + SC„[K,(4^(7j) + s47jf7)K, (4W^))]}
(2)6 day:
In 2
/, Zj bien Laplace
/W=
coi) - co)z + A.(3)
(l - &»)z + A (4)
KQ (r^ •^zf{z) j va K^ (r^ yjzf{z)) la ham Bessel bien ddi bae 0 va bae 1, tuong ung; S la he sd skin; va Co la anh hudng cua the tich chat luu trong thanh gieng dudi dang thii nguyen.
Sabet (1991) da phd bien ma chuomg trinh Fortran, khai thac giai thuat ciia Stehfest (1969) cho nghiem dugc dua ra bdi Gringarten (1979) nhu xem dudi day:
v^oy
I n ? ^ —
'-^z^{i)p,{^,)
(5)6 day:
N min I /:—
^ + 1 ^ 2 2
' D '=1
-+1
„ '+1
K^ (IK).
\(K^)\l-K).{2K-i).
(6)
P,{z,) la nghiem cua Gringarten (1979):
K,{^,)-vS47,K,{47,)
PXh)-
z, {47, K, (V^) + z, C, [K, (V^) + S47,K, (V^)]}
(7)Giao (2003) da nghien ciiu so sanh cac xap xi khae nhau cua ham sd gieng khoan va dl xuat mdt ky thuat so sanh dd thi tren may tinh cac dudng cong thi nghiem thir gieng khoan nude ngam sir dung phan mem Grapher. Ky thuat nay da sir dung trong nghien cim nay cho cae dudng cong thi nghiem ap suat trong dau khi.
PHUONG PHAP
1, Tao du-oTig cong chuan
Phuomg trinh (2) da dugc sir dung trong chuang trinh Wel_Frac dl tao cae dudng cong chuan. Cac dudng cong cho ba md hinh tir 1 din 3 dugc md ta dudi day va duge hiln thi trong Hinh 2 tr 5, tuong iing:
1040 Phan tich thi nghiem thir ^p sudt cho mdng ran nut ciia md Rang Ddjig^
• Md hinh 1: md hinh ddng chay trong mdi trudng ddng nhit cua mdt do rdng (Hinh 2).
• Md hinh 2: md hinh ddng chay gia dn dinh trong mdi trudng mit ne hai do rdng (Hinh 3).
• Md hinh 3: md hinh ddng chay khdng dn dinh trong mdi trudmg nirt ne hai do rdng (Hinh 4).
Hinh 2: Du'dng cong chuan cua mo hinh 1 (Mo hinh dong chay dong nhat)
: -
•-
-
X e "
'
. ^ - j ^ = ^ ^
jy^\'-;:^^^^'^
1 I I I I I I I
X o -
_
" " 10'
*=ctrrrr!T7. L 3 lo- I
1 1 J 1 1 . 1 1
100CO '
Hinh 3: Dvong cong chuan ciia mo hinh 2 (Mo hinh dong chay gia on dinh)
Hinh 4: Duong cong chuan cua mo hinh 3 (Mo hinh dong chay tam thoi)
Tuygn tap bao c^o Hgi nghj KHCN "30 nSm P k khi Viet Nam: CQ- hdi mdi, thach thuc mdi" 1041
.„„<,oooO o o o o -
o o »>oOOO°~
-
Hinh 5: DwoTig cong ap suat giam ap va thoi gian do ciia gieng BD-8X trung tam mo Rang Dong
Nhiing cai thien cua Wel_Frae tir chuomg trinh eua Sabet (1991) bao gdm:
• Wel_Frae ed the sinh cac dudng cong chuan cho ba md hinh dugc de cap d tren chir khdng chi rieng eho md hinh 1 nhu trong chuong trinh eiia Sabet (1991).
• Cae dudmg eong chuan duge lge tron la giam khoang each giiia diem [POX^C/^D)]! va dilm [PDXIL/CD)],.!-
• Wel_Frac se tinh toan ldi minh giai trung binh.
2. Phuo'ng phap so sanh do thi tren may tinh du'dng cong Idiao sat va du'O'ng cong chuan Theo quy trinh Giao (2003) de xuat, viee so sanh gitra dudmg cong khao sat vdi tap dudmg cong chuan cho md hinh ddng chay khae nhau eiia mdng nirt ne dugc tien hanh nhu sau:
• Vdi md hinh 1 (md hinh ddng chay trong mdi trudmg ddng nhat mdt do rdng):
Cac dudmg cong chuan eho md hinh 1 dugc tinh va ve trong Hinh 2.
Dudmg eong ap suat khao sat AP = P,- P theo thdi gian t dugc ve rieng ra trong Hinh 5.
Trong mdi trudmg dd hga ciia phan mem Grapher, dudng eong khao sat dugc chgn sau dd sao chep va dan sang do thi ehiia dudmg cong chuan. Bang each giii' nguyen viec bam chugt trai tien hanh dich chuyen tinh tien dudmg eong khao sat nhu trong Hinh 6. Qua trinh so sanh bang each giii chugt trai va di chuyen ca khdi hinh dudmg cong khao sat ket thiic khi timx dugc phan dudng cong chuan tuong ling va triing khdp nhat vdi dudng cong khao sat.
Luu y can ghi lai gia tri dudmg eong chuan triing vdi dudmg cong khao sat C^e va cap toa do dilm M tuomg img vdi he toa do {PQ, to/Cd) va {AP,t) eiing se dugc ghi lai. Diem Med the dugc chgn tai bat ky chd nao tren he toa do.
Luu y rang ket qua minh giai cua md hinh nay khdng tinh den hai thdng sd la u va &.
• Voi md hinh 2 va md hinh 3 (md hinh gia dn dinh va md hinh ddng chay khdng dn dinh trong mdi trudmg nirt ne hai do rong):
. Cac dudng cong chuin eho md hinh 2 va 3 dugc ve tren Hinh 3 va 4 tuomg img.
. Dudmg cong khao sat dugc ve d mdt hinh rieng nhu trong Hinh 5. Cac bude tuomg img dudi day la cho md hinh 2.
1042 Phan tich thi nghiem thii ap su5t cho mdng ran nut ciia md RarigJ)ong^
Trong mdi trudmg phan mem Grapher. dudmg cong khao sat ap suat dugc chgn, sau dd sao chep va dan sang dd thi chira dudng eong chuan bang viec bam chugt trai va di chuyen ea khdi hinh dudmg eong khao sat.
Bang viec dich chuyen tinh tien, tim kiem ba dudmg cong chuan tuong img vdi dudmg cong khao sat nhu sau:
• Mdt dudmg cong chuan {CDC'^cho cac diem sdm: dudmg cong nay tuong img vdi ddng chay tir nirt ne.
• Mdt dudng cong &e'^ ciia md hinh 2 (hoae d cho md hinh 3) (Hinh 9) cho cac diem gitia: dudng cong nay tuong img vdi giai doan chuyen giao, tire la d giai doan nay cd su bat dau tham gia ciia khdi matrix vao ddng chay.
• Mgt dudmg cong {CfjC )y.,„ cdn lai ia cho cac diem cudi: dudng cong nay tuong img vdi su tham gia toan phan ciia khdi matrix vao ddng chay (Hinh 9).
Luu y can ghi lai cac gia tri ciia CuC'^ va ae"'^ nhu thay trong Hinh 10, va gia tri toa do cua diem M trong hai he toa do{PQ, tifCN) va {AP,t) ciing cd the xem trong Hinh 10.
10000
Hinh 6: Sang to sir lien tuc ciia so sanh dirong cong chuan va du'O'ng cong lihao sat cho mo hinh 1
i
0 -A
i
\ < f . ) , - i
3
- y
'
CjC-' -- («>scTved
: ~r . . . •
pressure t ( h r )
0-01
; l „ " BJB33
I \
I ' A ' i ^ '
-<
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0 1 , 10
^ ^ ^ < 1
T^Too f^^^^"
5 ^ r ^ r ^ ^ ^ ^ ^
1 * • > « - ; - ^ i
1
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^ ' ^ ^
i - - • • ' ;
10000 I . ' ' .
Hinh 7: Ket thiic so sanh du'ong cong chuan va du'O'ng cong khao sat cho mo hinh 1
Tuygn tap bao cao Hgi nghj KHCN "30 nam Dau khi Viet Nam: Co hdi mdi, thach thuc mdi" 1Q43
Hinh 8: Ket thuc so sanh du-ong cong chuan va du'dng cong khao sat cho mo hinh 2
IniermediuK time
Hinh 9: Ghi lai cac gia tri tir du'dng cong chuan va dudng cong khao sat cho mo hinh 2
Hinh 10: Ket thiic so sanh du'dng cong chuan va dird'ng cong khao sat cho mo hinh 3 Quy trinh phan tich cho md hinh 3 ciing tuong tu nhu md hinh 2. chi khae d chd la thay vi duong cong &e^^ la dudmg cong 6. Ket qua so sanh cua md hinh 3 dugc the hien nhu Hinh 10.
3. Minh giai
Khi 2 cap toa do ciia dilm M la {P^, ttfCo)^ va {AP, t)^ dugc liy. qua trinh minh giai se tinh cac thdng sd sau:
IQ44 Phan tich thi nghiem thu- ap suSt cho mdng ran nut ciia md RangjDo£g_
a. Do thdm (Kj)
Ty sd giiia {PD).U va {AP)M cua diem M dugc sir dung cho tinh toan gia tri do tham nJiu sau:
^ _\4\.20Bp{P,Xi (8)
' h
(APL0 day: Kf la do thim nirt ne {mD); B la he sd thanh he {RB/STB); Q la luu lugmg ddng chay (thimg/ngay); a la do nhot cua chat luu {cp); va h la chieu day thanh he (ft).
b. Anh hw&ng thi tich chdt Iwu trong thdnh giing (C)
Ty sd giiia {tNCD).\i va (Ow cua diem M duge sir dung xac dinh.
c. Skin (S)
Khi anh hudmg thi tich chit luu trong thanh gieng da xac dinh d tren, C£y+,„ cd the dugc tinh nhu sau:
^ 0.89C
Gia tri C^e" tir dudmg cong chuan, noi cac diem xac dinh cudi tuomg img vdi CQC cua via la {Coe )/+,„• Cac gia tri Cof+m cua {CDC )/+„ dugc tinh toan hieu img Skin ciia gilng.
S = Un^ 'J^ (11) 2 C
d. Hi sd f CO j
Gia tri cua cac dudmg eong chuan, nai cac diem khao sat ap suat dau va eudi tuomg img vdi dudmg cong chuan la {Coe^^va (Coe^'^)/+,„.
2.S--
iCy')r.„
iC,e'-')j
^ = . ^ 2S\ ( 1 2 )
e. Hi sd (X)
Gia tri &e'' cua md hinh 2 (o cua md hinh 3) tir dudmg eong chuan, dugc so sanh tuomg img vdi giai doan gitia, dugc sir dung xac dinh thdng sd, thdng sd nay dac trung eho kha nang de dang trao ddi giiia eae khdi matrix va nirt ne.
A = (/le-"')e" (13) Trong md hinh 3:
. ic,y-'),,„, {c,y-'),^„,
^ = ^ - 1 7 ^ -> ^ - ^ ' - ^ ^ i ^ (14)
0 day: a = 1.89 cho trudmg hgp dang tam va a = 1.05 cho trudng hgp dang hinh khdi.
Tuygn tap bao cao Hdi nghj KHCN "30 nam DSu khi Viet Nam: CQ- hdi mdi, thach thuc mdi" 1045 4. Tinh toan loi minh giai trung binh
Sau khi sd lieu khao sat duge ve, dugc so sanh va duge minh giai, cac md hinh via se duge so sanh va thao luan vdi nhau nham tim ra md hinh tdt nhat. Ldi minh giai da dugc tinh toan trong bao cao nay nhu sau:
^_mf\{Poo),-{Po),
(15)6 day: d la loi trung binh minh giai (%); n la sd diem sd lieu; {Poo), la ap suit khao sat dugc chuyen ddi tuong iing tdi diem thii / va dudmg cong chuin.
{PiA={^)}^
(16)Q day: {AP)i la sir khae nhau gitia ap suit ban diu va ap suit khao sat tai dilm thii /;
(PD), la ap suat dugc tinh tuomg iing tdi dudmg cong chuin tai dilm thii /, cimg vdi thdi gian ti. Thdi gian t, cin dugc chuyen tuong iing vdi {to/Co)h tinh toan {ID/CD), dua tren edng thiie sau:
(',./c„),=(d^^^
V ' ) A /
M (17)
Gia tri d cang nhd thi dudmg eong ap suat khao sat cang gan vdi md hinh dudmg cong chuan ciia via da dua ra. Su xac dinh (P^,), va ldi trung binh cho ba md hinh da dugc thuc hien bang chuomg trinh Wel-Frac.
Hinh 11: So sanh loi minh giai trung binh CAC KET QUA AP DUNG
Sd lieu thir ap suat eua dudng cong khao sat ap suit va thdi gian, tir hai gilng khoan da dugc thuc hien tai gilng BD-8X va BD-13X ciia md Rang Ddng. Sd lieu dugc minh hoa trong Bang 1.
1046 Phan tich thi nghiem thu- ap suat cho mdng ran nut ciia md Rajig_Ddng.
Bang 1: So lieu ciia ket qua do giam ap cua gieng BD-8X va BD-13X, md Rang Dong BD-8X in central Break of Day field
GIVEN DATA B = (Va)c.)r-m =
P- = rw =
h = Pi = Q =
1.735 (RB/STB) 4.15E-06 (psi'^-1)
0,372 (cp) 0.35 (ft) 1349 (ft) 5103.24 (psi)
5432 (STB/day)
Drawdown test Time (t hr)
0.016 0.018 0.021 0.023 0.026 0.031 0.034 0.040 0.046 0.053 0.062 0.076 0.084 0.100 0.113 0.131 0.154 0.179 0.206 0.238 0.268 0.306 0.342 0.391 0.452 0.544 0.601 0.699 0.787 0.939 1.121 1.293 1.443 1.664 1.796 2.022 2.292 2.668 2.977 3.352 3.739 4.100
Pressure (P psi) 5097.65 5097.32 5097.11 5096.68 5096.52 5096.05 5095.80 5095.48 5094.94 5094.66 5094.36 5094.14 5093.98 5093.83 5093.66 5093.42 5093.42 5093.17 5093.00 5092.82 5092.56 5092.28 5092.19 5092.09 5091.81 5091.51 5091.23 5091.11 5090.80 5090.28 5089.95 5089.82 5089.48 5089.14 5088.78 5088.78 5088.41 5088.15 5088.03 -5087.64 5087.49 5087.49
AP = P i - P ( p s i ) 5.59 5.92 6.13 6.56 6.72 7.19 7.44 7.76 8.30 8.58 8.88 9.10 9.26 9.41 9.58 9.82 9.82 10.07 10.24 10.42 10.68 10.96 11.05 11.15 11.43 11.73 12.01 12.13 12.44 12.96 13.29 13.42 13.76 14.10 14.46 14.46 14.83 15.09 15.21 15.60 15.75 15.75
BD-13X in Northern Break of Day field
GIVEN DATA
B= 1.685 (RB/STB) (V(6cOf+m= 4.29E-07 (psi-'-l)
M= 0.361 (cp) rw= 0.35 (ft)
h = 1543 (ft) Pi= 5006.33 (psi) Q = 5521 (STB/day)
Drawdown test Time (t hr)
0.016 0.017 0.018 0.020 0.022 0.024 0.027 0.029 0.033 0.036 0.040 0.045 0.050 0.057 0.066 0.077 0.091 0.107 0.128 0.145 0.173 0.199 0.235 0.271 0.314 0.377 0.463 0.542 0.645 0.787 0.928 1.141 1.415 1.628 1.938 2.287 2.653 3.103 3.604 4.323 5.185 6.535 7.839 9.567 12.453 15.197
Pressure (P psi) 5001.11 5000.80 5000.47 5000.02 4999.58 4998.88 4998.44 4997.62 4996.94 4996.21 4995.16 4994.40 4993.27 4992.36 4991.42 4990.26 4989.01 4987.98 4987.05 4986.07 4985.21 4984.70 4983.96 4983.39 4982.61 4981.64 4980.59 4979.93 4978.81 4977.88 4976.71 4975.95 4974.92 4974.15 4973.06 4972.52 4971.37 4971.09 4970.47 4969.59 4968.65 4968.04 4966.74 4966.10 4965.39 4963.66
AP = Pi - P(psi) 5.22 5.53 5.86 6.31 6.75 7.45 7.89 8.71 9.39 10.12 11.17 11.93 13.06 13.97 14.91 16.07 17.32 18.35 19.28 20.26 21.12 21.63 22.37 22.94 23.72 24.69 25.74 26.40 27,52 28.45 29.62 30.38 31.41 32.18 33.27 33.81 34.96 35.24 35.86 36.74 37.68 38.29 39.59 40.23 40.94 42.67
Tuygn tap bao cao Hdi nghj KHCN "30 nam Phu khi Viet Nam: Co hoi mdi, thach thuc mdi" 1047
1. Ap dung cho gilng BD-8X o trung tam mo Rang Dong
a. Md hinh 1 (md hinh ddng chdy ddng nhdt chi ra trong Wnh 2) Kit thuc so sanh vdi dudng cong chuin (Hinh 7)
{Coe'')=10'
DilmM:(% = -lva « ^ = ^ ^
{AP)^ 2.5 (tJCX 10
• Minh giai:
Do thdm (Kf)
^ ^ 1 4 1 . 2 g ^ / / ( P j , , ^141.2x5432.00x1.735x0.372 1 _ i ^ g . o . „ j .
' h ( A P L 1349 2.5
• Anh hu&ng thi tich chat luu trong thdnh giing (C)
0.000295^^/2 (t) 0.000295x146.78x1349 0.033 ^ , , , , , , , ., C = -•—7 r — = = 0.52{bbl / psi)
p {t,/C,X 0-372 10 Skin (S)
C„,„, = ^!^^£-^ -. ° - f - ° - ^ ^ ^ = 672.48
^ {VipcX^nMl 4.15x10-'xl349x0.35' 1 [CIN'%„ i I A 2 A 2 Cyy^„, y
10
672.48 = -0.95
,-2
b. Mo hinh 2 (mo hinh dong chdy gid on dinh)
Ket thuc so sanh vdi dudmg cong chuan (Hinh 9):
{CDe^\= 10', {Coe^^n, = 3xl0", va Xe^^ = 10
DilmM:(% = ^ v a ^ i k _ - ^
(AP),, 3.69 (tJCX 10• Minh giai:
• Do thdm (K)
^ ^ 1 4 1 . 2 g ^ / ^ f e ) , , ^141.2x5432.00x1.735x0.372 1 _ n ^ ^ 3 . ^ .
^ h (AP)^ 1349 3.69
• Anh hu&ng thi tich chdt hm trong thdnh giing (C)
0.000295.^77 (t) 0.000295x99.45x1349 0.05 ^^ c-^^uu, > x C = —-.— ^'' .— = = 0.53{bbl / psi)
p ito/C,X 0.372 10 Hi sd (od)
CO = - 7 — V — = — = 0 . 3 0
( C > ^ 10' Skin (Sf
1048 Phan tich thi nghiem thu- ap suit cho mdng ran niit ciia md Rang j)dng^
C 0.89C 0.89x0.53
Df+m
(V<N,)f,„,hr^ 4.15x10-^x1349x0.35- 688.45 2 C
^ ^Df + m
0.51n ^3x10° ^
V 688.45 = -2.71 Hi sd (X)
A = (/le-")e" =10-^xe-^-^-^' =4.42x10"
c. Md hinh 3 (md hinh dong chdy khong on dinh)
Kit thuc so sanh vdi dudng cong chuan (Hinh 10):
2S- 2Sx
{Coelf= ^^10", {Coenpn. =10\ va p ^10
Diem M:
ML
(AP)M 4.25 va
(')„
(t,JC„)
M0.041 10 Minh giai:
• Do thim (Kf)
\4\.2QBp (P„L 141.2x5432.00x1.735x0.372 1
K, h (APL 1349 4.25
Anh hu&ng thi tich chdt luu trong thdnh giing (C)
0.000295Kjh {X 0.000295x86.34x1349 0.041 C =
M
{f,Jc,X
Hi sd ((a)
CO f+ni
0.372
10"
3x10"
10
= 86.34(mD)
0.31{bbl / psi)
= 0.33
Skin (S)
C 0.89C 0.89x0.37
Df+m
{V(/>c,)j.^,„hr^ 4.15x10"'xl349x0.35^ 480.17 5 = - I n 1
2 C (Coe^%.
= 0.5 In
Df+m
10"
480.17 = -3.08 He sd (X)
A = 1.05
(cy^f
1.05- 10"-2A:-3.( = 2.21x10"
J3e-'' lO'e"
2. Ap dung cho gilng BD-13X o phfa BSc mo Rang Dong
Ba md hinh ddng chay trong mdi trudng nut ne da dugc ap dung cho md Rang Ddng. Cac dudmg eong chuan cho ba md hinh nay da dugc tinh toan bang chuang trinh Wel_Frac. Su so sanh gitra dudmg cong chuan va dudng Ichao sat da dugc tien hanh bing phirong phap so sanh dd thi true tilp tren may tinh (Giao, 2003). Qua trinh so sanh va minh giai da dugc thuc hien tuong tu nhu trudng hgp BD-8X. Ket qua phan tich thir ap
Tuygn tap bao cao H^i nghi KHCN "30 nam Phu khi Viet Nam: Co' hdi mdi, thach thuc mdi^ 1049 suit cho gilng BD-13X thi hien Bang 2. Cac kit qua thu duoc chi ra ring md hinh 2 (md hinh ddng chay gia dn dinh) la md hinh phu hgp nhit trong phan tich thir ap suat cho da mdng ntJt ne cua md Rang Ddng.
Bang 2: T6ng ket cac ket qua phan tich thir ap suat
K{mD) C
{bbl/psi) S
u
&
&{%)
BD-8X Ddng
nhdt (Mo hinh 1)
146,78 0,52 -0,95
7,758
Gid dn dinh
(Mo hinh 2)
99,45 0,53 -2,71 0,3
4,42 X 10'^
2,142
Khdng dn dinh
(Mo hinh S)
86,34 0,37 -3,08 0,33
2,21 X 10-^
2,429
BD-13X Ddng
r
nhdt (Mo hinh 1) 42,87 0,70 -2,17
7,029
Gid on dinh
(Md hinh 2)
31,31 0,91 -3,45 0,1
1,01 X 10-^
1,262
Khong dn dinh
(Md hinh 3)
23,22 0,79 -4,53 0,1
1,22x10"^
2,873 KET LUAN
• Ba md hinh da dugc nghien cim gdm md hinh 1 (md hinh ddng chay trong mdi trudng ddng nhat mdt do rdng); md hinh 2 (md hinh ddng chay gia dn dinh trong mdi trudmg nut ne hai do rdng); md hinh 3 (md hinh ddng chay khdng dn dinh trong mdi trudmg nut ne hai do rdng). Chuomg trinh ciia Sabet (1991) eho md hinh ddng chay trong mdi trudmg ddng nhat mdt do rdng da dugc khai thac va cai tien cho viec tinh toan cac dudng cong chuan cho md hinh mdt do rdng va hai do rdng. Ky thuat so sanh do thi true tilp tren may tinh (Giao, 2003) dugc img dung de so sanh dudng cong chuan va dudmg cong khao sat bang sir dung phan mem phien ban mien phi cua Grapher.
• Dudng cong chuin cho md hinh 1 tdi 3 va quy trinh so sanh dd thi da dugc ap dung phan tich sd lieu thir ap suit d md Rang Ddng d Viet Nam tren hai sd lieu thir ap suat ciia gilng BD-8X va BD-13X. Md hinh 2 (md hinh ddng chay gia dn dinh trong mdi trudmg nirt ne hai do rdng) cho kit qua tdt nhat, ket qua tir md hinh 2 cd the lira chgn cho quan ly via Kf = 99,45mD; C = 0,53bbl/psi; u = 0,30; S = -2,71; & = 4,42 x W^
cho BD-8X; va Kf = 31,3ImD; C = 0,91bbl/psi; u^O.l; S = -3,45; & = 1,01 x 70"^
choBD-13X.
• Md hinh 2 la md hinh tdt nhit cho phan tich thir ap suit cua md Rang Ddng dua vao viec xac dinh ldi minh giai trung binh lin diu tien dugc de xuat tinh toan trong bao cao nay bang chuong trinh Wel_Frac. Ldi minh giai trung binh dugc dinh nghia la sir khae nhau giira dudmg khao sat va dudmg cong chuin, va da dugc tinh la 7,5%, 1,6%
va 2,5% cho md hinh 1, md hinh 2 va md hinh 3.
1 0 5 0 Phan tich thi nghiem thii- ap s u i t cho mdng ran nut cua md Rang j)dng^
KIEN NGHI
• Phuang phap so sanh dd thi true tiep tren may tinh dudng cong chuin \ a dudmg cong khao sat de xuat trong bao cao nay Kha don gian va dl sir dung, cd the ap dung cho cac md dau Idiac d phia Nam them luc dia Viet Nam bdi nd la edng cu re tien, de sir dung va nhanh, cd the ciing tdn tai song hanh vdi cae cdng cu phan mem thuang mai phirc tap.
• Su cai thien chuomg trinh Wel_Frac va ky thuat so sanh dudmg cong tren may tinh vdi cac phin mem khae nhu Matlab, MathCAD AutoCAD, v.v... nen dugc tiep tuc nghien cuu.
• Tiep theo, cac tac gia se du kien nghien cuu so sanh nghiem giai tich vdi nghiem sd cho ddng chay trong mdi trudng nut ne dua tren chuong trinh phan tir hiJu han da dugc phat trien bdi Giao (1994).
TAI LIEU THAM KHAO
1. Barenblatt G.E., Zheltov LP., Kochina I.N., 1960. Basic concepts in the theory of homogeneous liquids in fissured rocks. Joumal of Applied Mathematics, p. 1286 -
1303, Russia (Former USSR).
2. Bourdet D., Gringarten A.C, 1980. Determination of fissure volume and block size in fractured reservoir by type-curve analysis. Joumal of Society of Petroleum
Engineering, SPE 9293.
3. Giao P.H., 2003. Revisit of well function approximation and an easy graphical curve matching technique for Theis' solution. Ground Water, p. 418 - 422.
4. Giao P.H., 1994. Finite element quasi-3D modeling of flow in double porosity fractured medium. Special Research Study, Asian Institute of Technology, Bangkok,
Thailand.
5. Gingarten A.C, Bourdet D. et al., 1979. A comparison between different skin and wellbore storage type curves for early time transient analysis. Joumal of Society of Petroleum Engineering, SPE 8205.
6. Sabet M.A., 1991. WeU test analysis. Volume 8, Huston. Tokyo, Japan, 459p.
7. Stehfest H., 1969. Numerical inversion of Laplace transforms. Communication of the ACM, Frankfurtam Main, Germany.
8. Warren J.E., Root P. J., 1963. The behavior of naturally fractured reservoir. Joumal of Society of Petroleum Engineering, SPE 426.
