pab 3053 project 2

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Eclipse exercise adapted from Heriot-Watt University Reservoir Simulation module

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PAB3053RESERVOIR MODELING AND

SIMULATION

ECLIPSE

PROJECT 2 (Marks :10%)

General Instruction:

1.

Students are required to submit the hardcopy of the

report in my pigeon hole in Block 15, Level 2.

2. Please use the cover page provides. Report should

be printed double sided.

3. Report must be submitted no later than 5pmon

1stSept 2014. Marks will be deducted by 2% per

dayfor the late submission.

4.

All figures must be labeled clearly and referred

properly in the text while explaining your results.

5. Zero marks will be awarded for any plagiarism

works.

All the best.

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( Please use this Cover page)

RESERVOIR MODELING AND SIMULATION

ECLIPSEPROJECT 2 (Marks :10%)

Name : ___________________________

Student ID : _______________________

Signature : ________________________

Submit to : Abdelazim

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PROJECT 2 (10%)

(Simple layer sweep efficiency: viscous, gravity and capillary forces)

This exercise involves adapting file TUT1D.DATA Make sure that you have completed

Tutorial 1D before commencing Tutorial 2.

A - Two dimensional model with high perm in the middle layer.

Create a tut2folder, make a copy file TUT1D.DATA, and call it TUT2A.DATA

The objective is to make a more detailed cross-section model between the injector

and producer:

5 x 50 cells Layer 1

Layer 2

Layer 3

150'

2500'

X

Z

Injector Producer

5 x 50 cells

5 x 50 cells

Each layer has 5 x 50 cells to limit numerical dispersion. Go through the

following steps in editing the TUT2A.DATA file:

(a) Set number of cells, NX = 50, NY = 1, NZ = 15, in the DIMENS keyword, and

the maximum number of connections per well = 15, in the WELLDIMS keyword.

(b) Set grid dimensions to DX=70, DY=1800, DZ=10 for all cells. (Although the

model has the same overall pore volume as in Tutorial 1, it is now only 1 cell

thick in the Y direction.)

(c) There are now 15 layers of grid cells, distributed over 3 geological layers:

o geological layer 1 corresponds to grid layers 1 - 5

o geological layer 2 corresponds to grid layers 6 - 10

o

geological layer 3 corresponds to grid layers 11 - 15Define TOPS for only the first layer of grid cells (layer 1 - 1), but all poro/perm

properties should be assigned per geological layer (i.e. per 5 layers of cells).

Maintain the same PERMX, PERMZ, PORO and NTG values in each geological

layer as in TUT1D.

(d) Delete PERMY and associated data.

(e) In the REGIONS section change number of cells in each layer from 25 to 250

when allocating relative permeability tables to cells in SATNUM keyword:

SATNUM

250*2 250*1 250*2 /

3500

Vertical layers

Geological Grid cells

1 1-5

2 6-10

3 11-15

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(f) In the SUMMARY section remove WWCT (PROD), and replace with FWCT,

the field water cut. Add FWIT (field water injection total) and FOE (Field Oil

Recovery Efficiency) to the list of output variables.

(g) Place injector at (1,1) and producer at (50,1) and complete both over all 15

vertical cells.

(h) Set the injector to a rate control of 11,000 stb water/day (RATE) with a

maximum bottom hole pressure limit of 10,000 psia, and the producer to a liquid

production rate of 10,000 stb/day (LRAT), with a minimum bottom hole pressure

limit (BHP) of 2,000 psia.

(i) Water injection at this rate will result in the displacement of one pore volume

of after 2850 days, so set the time steps (TSTEP) to give ten tenths of a pore

volume:

TSTEP

10*285 /

Save the edited file.

Run Eclipse using the TUT2A.data file. Plot the following: field oil recovery

efficiency (FOE) and field water cut (FWCT) vs field cumulative water injection

(FWIT) on the X-axis. (You can use MS Excel, RE Studio, ECLIPSE Office

(Results) or Petrel for these plots. In Petrel this plot may be created by right

clicking on Water injection cumulative and choosing Select as X) Do not, at

this stage, save or print this picture. These graphs will be recreated in a

comparison between parts A to D.

B - High perm in bottom layer.

Copy TUT2A.DATA to TUT2B.DATA

Edit the new file to place the high permeability layer in the bottom instead of the

middle, i.e.:

layer 1: PERMX = 250mD



Alter the PERMZ, PORO, NTG and SATNUM keywords to reflect the layer

changes also. Run Eclipse again and plot the same graph as above, but this time

for both cases 2A and 2B. Inspect the grid saturations of A and then B using

Petrel or Floviz to identify causes of any difference in production between A and

B.

C - High perm in top layer.

Copy TUT2B.DATA to TUT2C.DATA. Edit the new file to place the high

permeability layer on top, and run Eclipse. Use Petrel or Floviz to investigate thegrid saturations for C. TUT2C will form the base case, with all the subsequent

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models being compared to this one. The files for the remaining models will all be

edited copies of TUT2C.DATA.

D - Slower frontal advance rate.

Copy TUT2C.DATA to TUT2D.DATA. Edit the new file so that instead of

injecting 11,000 stb water/day only 1,100 stb/day are injected, instead ofproducing 10,000 stbl/day only 1,000 stbl/day are produced, and the timesteps are

increased from 285 to 2850 days each.

On Figure 1display the field oil recovery efficiency (Y-axis) vs field cumulative

water injection (X-axis) for A - D. On Figure 2 display the field water cut vs

field cumulative water injection for the four models. Using Petrel or FloViz,

generate grid displays of the saturation profiles at time step 2 and time step 5. In

MS Word create Figure 3with four saturation plots (A-D) for time step 2 and

Figure 4with four saturation plots (A-D) for time step 5. (In FloViz use menu

View->Set View->Front, exaggerate by a factor of 10 in the z direction, then

View->Hardcopy colours and then either File->Save Image->Image File to savea jpeg file, or use Alt-PrintScrn to copy bitmap to the clipboard, from where the

image may be pasted directly into MS Word (Ctrl-V). For Petrel, follow the

instructions in the separate Petrel introduction file)

What are the main differences in production behaviour between the four models,

and why? How would the profiles in D compare with the other cases if plotted

against time instead of volume of water injected.

EIncreased cross-sectional area away from wells.

Copy TUT2C.DATA to TUT2E.DATA. Change the thickness of the cells so thatclose to the wells they are narrow, but in between the wells they are broad. To do

this, delete the old definition of DY under EQUALS, and inserta new definition of

DY above the EQUALS keyword:

DY

2*140 2*420 2*700 2*980 2*1260 2*1540 2*1820 2*2100 2*2380 2*2660

2*2940 2*3220 2*3500

2*3220 2*2940 2*2660 2*2380 2*2100 2*1820 2*1540 2*1260 2*980 2*700

2*420 2*140

2*140 2*420 2*700 2*980 2*1260 2*1540 2*1820 2*2100 2*2380 2*2660

2*2940 2*3220 2*3500

2*3220 2*2940 2*2660 2*2380 2*2100 2*1820 2*1540 2*1260 2*980 2*700

2*420 2*140

repeat for all 15 layers

/

These changes will maintain the overall volume of the system, but ensure thatflow speeds in mid-field will be only 4% of the flow speeds in the near wellbore

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region. Run ECLIPSE and again inspect the saturation profiles using Petrel or

Floviz. (Note Petrel and Floviz will not show a grid with variations in thickness

in the Y direction here, but changing the display properties to Initial: DY will

allow you to check that you have entered the DY values correctly.)

F - Increased kv/kh.

Copy TUT2C.DATA to TUT2F.DATA. Edit the new file so that the model has a

kv/kh ratio of 1 instead of 0.1 (i.e. make PERMZ 1000, 200 and 200 mD in the

three layers). Run Eclipse again and inspect the saturation profiles using Petrel or

Floviz. Do not print the figures.

G - Barriers preventing vertical flow.

Copy TUT2C.DATA to TUT2G.DATA. Instead of changing all the grid cell

vertical permeabilities, the transmissibilities between the three layers are to be set

to zero. In the EQUALS keyword, between the layer 1 and layer 2 definitionsinsert the following:

MULTZ 0.0 1 50 1 1 5 5 /

and between the layer 2 and layer 3 definitions insert:

MULTZ 0.0 1 50 1 1 10 10 /

This will prevent any flow between grid layers 5 and 6, and between grid

layers 10 and 11. Again run Eclipse and Petrel or FloViz to inspect the

saturations. Plot the field oil recovery efficiency vs time for C, E, F, and G onFigure 5. Create a separate plot with field water cut vs time for the same four

models on Figure 6. Create Figures 7&8, similar to Figures 3 &4, but for C, E,

F, and G.

What variations in pressure gradient will be encountered as injected water moves

away from the wellbore into the formation, and which forces will tend to

dominate in the variousregions? Discuss the geological reasons why the kv/kh

ratio might vary in reality. What difference does it make whether the kv/kh ratio

is reduced/increased throughout the reservoir rock, as in F, or whether

transmissibility barriers exist between layers, as in G?

H - Zero capillary pressure.

Copy TUT2C.DATA to TUT2H.DATA. Set the capillary pressure in the new

model to zero. Do this by setting all the Pc values in the SWOF tables to 0.0.

What is the effect on oil recovery of setting capillary pressure to zero, and what

conclusion do you draw about its effect on the reservoir flow behaviour?

I

Grid coarsening.

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Copy TUT2C.DATA to TUT2Ccoarse.DATA. Here we are going to leave the

same level of grid resolution in the cells around the wells, but coarsen the cells in

the centre of the model from 70 ft in the X-direction to 1,400 ft, and coarsen all

cells in the Z-direction from 10 ft to 50 ft.

Change the number of cells to NX=12, NY=1, NZ=3, in the DIMENS keyword.

In the EQUALS keyword change the DX and DZ values

EQUALS

-- Keyword value X1 X2 Y1 Y2 Z1 Z2

DX 70 1 5 1 1 1 3 /

DX 1400 6 7 1 1 1 3 /

DX 70 8 12 1 1 1 3 /

DY 1800 1 12 1 1 1 3 /

DZ 50 /

Also remember to change the X1, X2 and Z1, Z2 values for all other properties in

the EQUALS keyword to reflect the new grid dimensions.

Change SATNUM to reflect the fact that there are now only 12 cells in each layer.

Change WELSPECS and COMPDAT to reflect the grid dimension of 1-12 cells

in the X-Direction and 1-3 cells in the Z-Direction.

Copy TUT2Ccoarse.DATA to TUT2Hcoarse.DATA, and make Pc=0 in

TUT2Hcoarse.DATA.

Run TUT2Ccoarse.DATA and TUT2Hcoarse.DATA

JGrid refinement.

Here we refine the model by a factor 5 in the X-Direction and a factor of 5 in the

Z-Direction (all cells will be 14 ft X 1800 ft X 2ft).

Copy TUT2C.DATA to TUT2Crefine.DATA:

In RUNSPECadd

AUTOREF

5 1 5/

In RUNSPECadd

LGR

4 432 /

To create a single column radial local grid refinement,

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In GRID add

RADFIN

'SOUTH' 1 1 1 15 6 4 18 /

--INRAD

--0.2 /

ENDFIN

In Schedule, add

WELSPECL

PROD G1 SOUTH 1 1 8000 OIL /

COMPDATL

PROD SOUTH 1 1 1 15 OPEN 2* 0.6667 /

/

These keywords will automatically refine the model and allocate more memory

space for the calculations.

Run TUT2Crefine.DATA

Plot FOEvs time for cases TUT2C, TUT2Crefine, on Figure 9, and FWCT vs

time on Figure 10.

What is the impact of capillary pressure in the coarse models? And in the refined

models? What is the level of resolution required in the cases with capillary

pressure, and in the cases without?

SENSITIVITIES

Polymer Flooding

Model viscous oil: Copy TUT2C.DATA to ViscOil.DATA and increase the

viscosity of oil by a factor of 5 (multiply each of the viscosities in the table by 5).

Model polymer injection to sweep more viscous oil: Copy ViscOil.DATA to

Polymer.DATA, and add in the following keywords to inject a polymer solution

with a viscosity = 10 cP:

in RUNSPEC section

-- Switches on polymer option (no associated data)

POLYMER

in PROPS section

-- viscosity multiplier vs polymer concentration

PLYVISC

-- concentration multiplier

0.00000 1.0

1.00000 12.5/

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-- 1.0 * 0.8 = 0.8 cP (water viscosity)

-- 12.5 * 0.8 = 10 cP (polymer viscosity

-- 3 keywords switch off polymer adsorption

PLYADS

0.0 0.0

1.0 0.0 /

0.0 0.0

1.0 0.0 /

PLYROCK

0.0 1.0 1.0 1 1.0 /

0.0 1.0 1.0 1 1.0 /

PLYMAX1.0 0.0 /

-- degree of mixing between injected polymer solution and formation water

TLMIXPAR

1.0 /

in SCHEDULE section, after WCONINJ

WPOLYMER

-- well name concentration

INJ 1.0 //

Does adding polymer improve the sweep efficiency and the recovery in the viscous oil

scenario? What about in the original low viscosity oil case?

pab 3053 project 2

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