Isopach Mapping Uses

• for predetermining drilling depths to specific horizons in wildcat wells

• to locate buried structures in regions where formations habitually

become thinner over structural crests.

• In estimating the elevation of a datum bed below the total depth of a

well that penetrated a higher known stratigraphic horizon.

• To calculate the volume of oil in a formation

Isopach Mapping Definition

• An individual line connecting points of equal thickness is called an

isopach line.

• An isopach map is a map showing lines connecting points of equal

formation thickness

Isopach Mapping background

Isopach Mapping background

Isopach Mapping Deviation

TVD for a deviated well and

horizontal bed

TVD for a vertical well and a

dipping bed

cosMTTST cosMTTST

Isopach Mapping Deviation

TVD for a deviated well and

dipping bed

cosMTTST

Isopach Mapping Exercise

1. Post each well of the following table with the correct value of net pay on the

attached map.

2. Contour the map using a 30 feet contour interval (isopach map).

3. Include title box and legend

Well # Location Net Pay (ft)

1 PSL BLK 27 section 6 49

2 PSL BLK 27 section 5 0

3 PSL BLK 27 section 7 101

4 PSL BLK 27 section 8 34

5 PSL BLK 27 section 9 0

6 PSL BLK 27 section 17 0

7 PSL BLK 27 section 18 13

8 PSL BLK 28 section 1 0

9 PSL BLK 28 section 12 38

10 PSL BLK 28 section 13 158

11 PSL BLK 28 section 14 0

12 PSL BLK 28 section 24 0

Well # Location Survey Block Section Net Pay, ft

1 1980 FSL, 1980 FEL PSL BLK 27 6 49

2 k PSL BLK 27 5 0

3 SE NW PSL BLK 27 7 101

4 1980 FNL, 1980 FWL PSL BLK 27 8 34

5 J PSL BLK 27 9 0

6 SE NW PSL BLK 27 17 0

7 1650 FNL, 1980 FEL PSL BLK 27 18 13

8 J PSL BLK 28 1 0

9 NW SE PSL BLK 28 12 38

10 1320 FNL, 1320 FEL PSL BLK 28 13 158

11 NE PSL BLK 28 14 0

12 G PSL BLK 28 24 0