Integrated reservoir exercise
Main goals and steps To be able to identify a reservoir using a simple set of well and seismic data 1. Identify the location of the seismic and well data in the map 2. Identify the wells in the seismic data 3. Identify 3 main reservoir levels in well A. It is important to analyze carefully the GR, resistivity logs, and also the petrophysical properties 4. Correlate with well B 5. Select the best reservoir and identify it in the seismic data. Also, identify the main seismic reflections and structural patterns 6. Interpret the reservoir, the main reflectors and main faults in all the seismic data. Make a structural map of the top of the reservoir 7. Assuming that the area extent of the reservoir is the black rectangle in the basemap, make a volumetric calculation of the reservoir. 8. Use the following values for: • Bo: 1.25 • RF: 0.3 • Shc: 0.7 • Other values come from the geological assessment from the data provided
Key questions to answer
What is the environment of deposition? What is the dominant structural style in the reservoir area? What is the amount of oil in place? How much are the reserves? What will be the best way to develop the field?
Or t
ra c
e
N
Well A
Well Well B
B
3D seismic survey basemap
2
2
2
2
2
Well A: Well-Synthetic-seismic correlation
Scale: 500 ft/in Scale TVD: OFF
[4 5] [0 ] Feet Time 10000
10500
2600 11000
11500
12000 2800
12500
13000
10-Log
7-Log
8-Log
9-Log
2-<Sonic>
3-<Density>
4- <R C>
5-<Syn>
6-^Syn
12-SeisWorks Seis 1D SYN T 8-14-40-60 :sm :0 Nor Pol
1 2- S ei s Wo rk s Se is 1D SYN T 8-14-40-60 :sm :0 Nor Pol
C A L - R u n : 1 V e r s : 1G R - R u n : 1 V e r s : 1I L D - R u n : 1 V e r s : 1 C O N D - V e r s <: 1D T - R u n : 1 V e <r sR: H 1 >O B - R u n : 1 V e r s : 1 >< R C > < 1 D S Y N > 1 D S Y Nm e r g e / L i n e 3 1 1 5 \ m e r gme e. 3r dg ve / T r a c e 2 6 8 7 \ m e r g e . 3 d v api us/ft g/cm3 L > H =T( +5)- 1 0 - 5 5 - 6 0 : s m : 0 < > Line # Trace # Nor Pol 0 10 20 30 0 50 100 150 0 200 400 1000 500 0 150 100 50 1.5 2. 0 2.5 - 0 . 30 . 3 Rev Pol 2680268526902695 31053110311531203125
Well A time-depth table Time (msec) 0
500
1000
1500
0 2000
Depth (feet)
4000 6000 8000
10000 12000 14000
y = 0.0008x 2 + 2.2625x R2 = 0.9997
2000
2500
3000
GR facies
Behavior
Blocky
Fining upwards
Spike and erratic
Possible facies and environment, based on core description
Sequence stratigraphic framework
Fluvial channel, distributary channel. Fluvial-tide influenced delta
Progradational system, possible erosive surface at the base ( SB or ravinnement surface)
Tidal channel, fluvial channel (meander-mud plug on top) Crevasse splay, delta plain, tidal bar. Marine influence on delta or estuarine deposits
Progradation, transgression Transgression, possible ravinements surface at the base of main sandstone bodies Marine flooding, transgression
Erratic
Lagoon, tidal flat. Shelf deposits
Mixed
Tidal flat, tidal channel, tidal bar. fluvial or delta marginal deposits influence by marine processes.
Transgression
Mouth bar, delta front
Progradation
Coarsening upward
Depth (feet)
Permeability (md) 0
1000
2000
0
3000
10
20
30
10500
10500
10600
10700
10700
Well A petrophysical properties
10800
10900
10900
11000
11100
11100
100000 10000
11300
1000
Depth (feet)
11400
11500
11500
11600
11700
11700
11900
12100
12200
12300
12300
12400
12500
y = 0.042e0.4x R2 = 0.5955
10 1 0
5
10
15
20
0.01
y = 0.005e0.5318x R2 = 0.8575
0.001
12000
12100
100
0.1
11800
11900
P e r m e a b ility ( m d )
11300
Porosity (%)
11200
y = 0.7247e0.3218x R2 = 0.4323
12500
Porosity (%)
25
30
35