Page 151 - Fundamentals of Gas Shale Reservoirs

WELL LOG ANALYSIS OF GAS SHALE RESERVOIRS 131
(a) (b)
250 R = 0.07 250 R = 0.45
Generated HC (bbl/ac-ft) 150 Generated HC (bbl/ac-ft) 150
2
200
200
2

100
100
50

0 50
0
1 2 3 4 1 2 3 4
TOC (wt%) iTOC (wt%)
(c)
250 R = 0.68
Generated HC (bbl/ac-ft) 150
2
200

100

50

0
420 430 440 450 460
T max (ºC)

FIGURE 6.11 Cross‐plot analysis between generated hydrocarbons with (a) TOC, (b) iTOC, and (c) thermal maturity indicator (T max ) (data
from Modica and Lapierre, 2012).

(a) (b)
3.5 4
2
2
3 R = 0.99 3.5 3 R = 0.90
iTOC (wt%) 2.5 iTOC (wt%) 2.5 2

2

1.5 1.5

1
1 1.5 2 2.5 3 3.5 1 1.5 2 2.5 3
TOC (wt%) TOC (wt%)
FIGURE 6.12 Cross‐plot analysis between iTOC and TOC for (a) data points in oil window and (b) gas window.

Kerogen volume could be computed using the below ρ is determined using mineralogy logs, ρ is assumed as a
k
nk
formula by rearranging formula 6.12: fixed value between 1.1 and 1.4 g/cm , and ρ is computed
3
m
from bulk density and total NMR porosity:
K nk m (6.21) m b f (6.22)
nk k 1