查看完整版本: 数值模拟中块中心网格与角点网格的选择

数值模拟中块中心网格与角点网格的选择

数值模拟中块中心网格与角点网格的选择#RbL"f|W

T kFnycP,g$G5}&K 在进行模型网格化之前，选择那种网格模型十分重要。通常块中心网格与角点网格是用得最为广泛的两种网格。这里主要介绍如何区分以及选择这两种网格，、以及用实例来说明其区别，并介绍其网格模型参数的选择。a K1F/ra:g7D2y&L)S
1，特点8kb'KG#_P5H
（1）Block Centred Geometry
;]&vs;FV7rr*C:W Block Centred (BC) geometry requires for each cell a top depth plus a cell size in the X,Y and Z directions. The upper and lower faces are flat and horizontal and the cell sides are flat and vertical. The cells are all rectangular.
\ L^.\OyX(`8I*H Keywords used to specify Cartesian BC geometry are TOPS, DX (or DXV), DY (or DYV) and DZ.0pA\"tMr*w,V
Keywords used to specify radial BC geometry are DR (or DRV), DTHETA (or DTHETAV) and  DZ. Keywords ending in a V are the vector format keywords which are the vector equivalents of their standard alternatives.
^TqsUGe(L Since each cell is defined using only four real numbers, BC geometrical descriptionse4jw:hph
tend to be less voluminous than their CP equivalents. ** models using BC geometry can even be constructed without the use of a pre-processor such as GRID.M1j0W2pQ _
Consider adjacent BC cells. In a sloping structure, then their TOPS depths will be(M:o:t'Xn
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different. Likewise, the TOP depths of cells either side of a fault will be different. BC
;^Th#I%g9f]skj geometry effectively ignores the distinction between a slope and a fault. For example,:a2XnPZ3IJx
without a structure map as guide, a cross-section such as in Figure 35 could be either;z/hf7GO Q"t
sloping or heavily faulted.P$qX}j
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7f/APG Yk2XCRr BC geometry does not contain enough information to calculate the overlapping area-_U!INP
between neighbouring cells. This is because the cell corner depths are unknown. Fluids usually flow between neighbouring cells so a connection needs to be established./@2^8Ujb;`)_
ECLIPSE assumes that cells having neighbouring indices, such as those linked by arrowsin Figure 35 are connected even though they should not be. Also, the cells that appear to have overlapping faces in Figure 35 are in reality not connected. This is a result of ** no distinction between faults and dip changes in BC geometry.
C6~jvc （2）Corner Point Geometry+_eCPsGJ4](W
Corner point (CP) geometry is based on the notion of co-ordinate lines and corner
yy M%l)OvG'jT t depths. A co-ordinate line defines each edge of each column of cells. Co-ordinate linesare always straight but need not be vertical. The X, Y and Z locations of one point above and one point below the grid define each co-ordinate line. Cells are then defined by fixing their corners at set elevations along each co-ordinate line. This permits the cells to have any physically valid shape: sloping su**ces, fault planes, pinchouts and erosion su**ces can be represented correctly. Since each cell is defined by four coordinate lines and eight corner depths CP geometry tends to be more voluminous than the BC equivalent and almost always requires a pre-processor such as GRID for construction.
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CP geometry contains enough information to calculate the overlap between adjacent
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cells since the cell corner depths are known. This means that in Figure 36 only those
)x`n bun cells that visibly share an inte**ce are in fact in communication. So, fluids in the cells
s(xA Cr-}$xw indicated by arrows cannot flow across the fault.
x8B'v$EG M 2，区别与选择要点：
,K0{{{TK8c1Yg CP and BC have their respective advantages and disadvantages. The following tableoW,p+U2{ux
summarises them:
h)MwM1f.~wh&fN BC        CPlxo9t4uy
Cell description is **        Cell description is complex
]:w0Z4j#K? erI*k Pre-processor is not always
%t9uK_"pNWo
[X essential        Pre-processor is essential!n7u*I(@7},w$@;t
Compatible with many other;x4G)\Cj
simulators        Compatible with many other
&t@n(E s simulatorstgx2{%X~'\6|W o
Difficult to model irregularBx u,M*v$I1[NK
structures        Difficult to model irregularyW"\1v)Z2T
structures0s!GM s(E7N&]
Geometry data is not large        Geometry data is large
?O&K mFbN Cannot distinguish dip from
-`4?"J&V/sm*i faulting        Distinguishes dip from faulting7[*{Gh.O+pRI-K^w
Pinchouts and erosion su**ces aret6er"w'i&M+o#qE
difficult to model faithfully        Pinchouts and erosion su**ces are?QA%cL:KP
modelled faithfullymW6f^.C#xc:T e
Establishes incorrect cellj[ a PQ(Bre"CB#Ir5F
connections across fault planes.
A7Yy0f;KS8BKTk-v-u Hand modifications are required.        Layer contiguity across fault planes1I D6X }-_$kDv
is accurately modelledu!m:m0] S)P
Radial models are easy to construct        Radial models are very difficult to
~ `SClQL5P construct without a pre-processor
` o$w&PG:P8~L!~ 3，实例B]7m
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（1）Block-Centred Geometry Example%OU;zq,Y%O ?2d

7g*pg{$YzUc 模型要点：
5YAGr*N.R3lZ •The model is a 20 * 5 * 10 sector
&T |]az$K •The model slopes in two dimensions from (1, 1, 1) which is the shallowest cell.
.Uo#wL0gf izA •Blocks are 300 ft in X by 1000 ft in Y
}W{4t\p6] •Layer thicknesses are 32, 22, 20, 4, 32, 4, 26, 26, 4, 28 ft from the top downwardsGa*E
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•This is derived from a CP example shown on on page 122U
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模型参数设置：o2q,yi-X\$Q8EIP
The following keywords contain the entire geometrical description of the structure in
tB;g\T"BQik:_? Figure 37:
"n7[j*x[(Y3VX4F TOPS|;tN/]eK C9b Xo;S
--The first 20 TOPS define (1, 1, 1) to (20, 1, 1)?:PKOZ:Y
6855.000 6865.000 6875.000 6885.000 6895.000
u0tXXi$G 6905.000 6915.000 6925.000 6935.000 6945.000"J7ELWyO0S{
7005.000 7015.000 7025.000 7035.000 7045.000
x3YLD,YiSL1Y#v 7055.000 7065.000 7075.000 7085.000 7095.000
%a!zof D4[&h1Rd --The next 20 TOPS define (1, 2, 1) to (20, 2, 1)
_:@2\(l M+H9l2` 6930.000 6940.000 6950.000 6960.000 6970.000 `:e,J)c(^ik
6980.000 6990.000 7000.000 7010.000 7020.000Y
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7080.000 7090.000 7100.000 7110.000 7120.000-k$]'_
x.s0l
7130.000 7140.000 7150.000 7160.000 7170.000
RM [f#wI1Wg --The next 20 TOPS define (1, 3, 1) to (20, 3, 1))QN;i#CW dz
7030.000 7040.000 7050.000 7060.000 7070.000 ry?s [[
7080.000 7090.000 7100.000 7110.000 7120.000 ]%D.rMsO5Xx
7180.000 7190.000 7200.000 7210.000 7220.000 Y8_ `wq
7230.000 7240.000 7250.000 7260.000 7270.0008}#W'pZ6P5m5o
--The next 20 TOPS define (1, 4, 1) to (20, 4, 1)Vw+|~"Hg Gp
7130.000 7140.000 7150.000 7160.000 7170.0002e'`@j7l@;rR
7180.000 7190.000 7200.000 7210.000 7220.000in(A*e,U
7280.000 7290.000 7300.000 7310.000 7320.000
{'E?0F1cV(D-K6B&C1k 7330.000 7340.000 7350.000 7360.000 7370.000
gaq\l@ --The next 20 TOPS define (1, 4, 1) to (20, 4, 1)1Q9uIlB6tE'F]h E
7205.000 7215.000 7225.000 7235.000 7245.000&?\C.m_3E|%Z)_ s&U
7255.000 7265.000 7275.000 7285.000 7295.000G'j;Y%j f8M
7355.000 7365.000 7375.000 7385.000 7395.000KhO6CYLq
7405.000 7415.000 7425.000 7435.000 7445.000E4t{|4hlR9Il
/ This completes TOPS for the first layer
)O6d^+}h --No more TOPS are needed. Eclipse will add the DZ values6n)\G1],d#i
--to TOPS to calculate TOPS for successive layers
|on Ke Xi DX{.o CL'jJ
--All cells have DX=300.I)t` q*vr/yyhYY
1000*300 /
@9u0VtcH$SyoWy? DY
9Ju,N@-|s%v MV{6N5` --All cells have DY=1000
oW8Pj:NnHF8m 1000*1000 /gn)L:P/s%X6ai
EQUALS!a_-wx!u;@8` O
6FKOXPEHUJHUC]C.@j-qA.W;S
Eclipse 100 User Course Page 120 of 499 24/09/98
F7ldk:Hj --Set DZ layer by layerh)d&Q/]A
--ArrayValue I1 I2 j1 j2 k1 k2
4pS.@_&H_6W ’DZ’ 32 1 20 1 5 1 1 /{
?\#F&v]&CQ
’DZ’ 22 1 20 1 5 2 2 /V6v,z;c D
S9^
’DZ’ 20 1 20 1 5 3 3 /*WV{v*_r
’DZ’ 4 1 20 1 5 4 4 /
X&CB#l][J!QSjA ’DZ’ 32 1 20 1 5 5 5 /(B^:W0a7|P6e
’DZ’ 4 1 20 1 5 6 6 /
8e2WL{Q)U6S`,kU ’DZ’ 26 1 20 1 5 7 7 /P%o&Ut'`"SY(e.Q i$XfF
’DZ’ 26 1 20 1 5 8 8 /I_7u;_1D7^m+M{3P
’DZ’ 4 1 20 1 5 9 9 /:m8A2\)N |~ GIV
’DZ’ 28 1 20 1 5 10 10 /
+o([mp$jF /
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?%G nyeA+X"i;~ （2）Corner Point Geometry Example
1ol+l yOQh7GjRU m m8Xm.s2Mo L
模型要点7|2s4j8o @ n#a_
•The grid is the CP version from which the BC grid on p.118 is derived
zvU6jP •Co-ordinate lines define the vertical or sloping edges of the cells
%aMQ:j&P/@ •Neighbouring cells share co-ordinate lineszzcD:lO&L%Y5E
•The COORD keyword contains this information
,q D#k-M:|$F8j •There are eight corners per cell Ap#^gvq5H
•The ZCORN keyword contains this information

]7[7Zsi\4f1I 模型参数设置：
&eo"V6Q3z9W The following keywords are a small fraction of the data required to specify the
J3~A0h0J geometry of the structure in Figure 38.
P%Wz(_"A[M(~Z COORDXC({3\7]+q
--This defines the co-ordinate lines
)L8^k5rc'G --X1 Y1 Z1 X2 Y2 Z2O-kX'|2d
0. 0. 6825.000 0. 0. 7023.000
4cF BDl:U8c7\Kq 300.0000 0. 6835.000 300.0000 0. 7033.000
1gl$u5ku;`'?:i6PT 600.0000 0. 6845.000 600.0000 0. 7043.000:z.p
T NLVP8UQg
900.0000 0. 6855.000 900.0000 0. 7053.000
-v R{s/h+~Z/v%^ 1200.000 0. 6865.000 1200.000 0. 7063.000j+Kr2l?Z
..........N \VK%sX
..........
t,feh{U ..........
f9Ac U\'a!q7U / For a 20 * 10 model, 21*11 co-ordinate lines are required, i.e. 231.+x:Z!}y)W)S~e
?
--Each is defined by 6 numbers so 1386 numbers follow the COORD
.u0d ^U+PG keyword.3Ll`X jo$ic V3^2jX
ZCORN
O\ yx;LvU+j --This defines the cell corner depths in order X (or R) cycling
)Fy/d?/k{,| fastest],])~DQM
--then Y (or THETA) then Z
iKQeT3@,hM6? 6825.000 6835.000 6835.000 6845.000 6845.000
{CyI,V(y9o6a 6855.000 6855.000 6865.000 6865.000 6875.000IUBDBs MZ'G(o |
6875.000 6885.000 6885.000 6895.000 6895.0000{M7x+n G,a
6905.000 6905.000 6915.000 6915.000 6925.000
*WG:q:KP Z0^x.K'w 6975.000 6985.000 6985.000 6995.000 6995.0008Q]X ~kDt1Lq
7005.000 7005.000 7015.000 7015.000 7025.000
9w2Gi.v6x(D 7025.000 7035.000 7035.000 7045.000 7045.000S\eb.?4i avv&E?
7055.000 7055.000 7065.000 7065.000 7075.0001~KnKrStY
............pTA_"nM
............XI~#b!A{nT
...........k5E H0Dw
/ For 1000 cells, 8000 ZCORN values are required
,jj].qR!Qn Z'{D4\*i8Xz]D|C
[[i] 本帖最后由 yankai 于 2008-9-29 01:03 编辑 [/i]]

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