Click to return to HTML.

T.S.I.
Tecto Sedi Integrated
PDVSA

Bore-hole updip
A Bore-hole downdip
B
Shell vs Subsurface Consultants Shell vs Subsurface Consultants
Isochore = TVT Isochore = TVT
TVT = TVD Thickness TVT = TVD Thickness
TVD TVD
TVD
isopach TVD
A
true vertical A
isopach
thickness
isochore
isochore
B true vertical
thickness
After Shell Standard Legend (1995) B After Shell Standard Legend (1995)

It is vital to integrate and understand well deviation and bed dips; this is especially true
when interpreting stacked Bischke plots for which a correction for the well deviation is
necessary in order to compare isochores.

∆d/d

-900
KM
A nice linear trend seen in a Bischke plot does not necessarily
means that the stratigraphy is correct, thus:
KI
Note the scatter KD

due to the hydrodynamic

conditions of deposition
A forced layer cake stratigraphy could appear perfect using a
Bischke Plot or any of the modified Multiple Bischke Plot Analysis.
P78
S
3 P10
0

In all cases isopach, paleogeographic and net to gross maps

A very linear trend need to be used in order to validate the MBPA findings.
P23
does not necessarily
-1200
means perfect
P32
correlation Any conclusion from a Multiple Bischke Plot Analysis needs to be
corroborated by other lines of evidence especially dipmeter or
3

14250 15000 15750

References
Bischke, R.E., 1994, Interpreting sedimentary growth structures from well log
and seismic data (with examples), American Association of Petroleum
Geologists Bulletin, vol. 78-6, p. 873-892

The Multiple Bischke Plot Analysis is a very powerful tool: Bischke, R.E., Finley, W. and Tearpock, D.J., 1999, Growth Analysis (∆d/d):
Case Histories of the resolution of correlation problems as encountered
while mapping around salt, Gulf Coast association of Geological Societies
- To objectively validate or review any existing geological or seismic Transactions, Vol. XLIX 1999, p. 102-110
correlation consisting of at least 10 markers
Chatellier, J-Y., de Sifontes, R., Mijares, O. and Muñoz, P., 1999, Geological
and production problems solved by recognizing the strike slip component
- To identify or confirm unconformities, sequence boundaries, wrong on reverse faults, VLA-31, Lake Maracaibo, Venezuela, SPE Annual
Technical Conference, Houston, SPE No. 56558
correlations or low angle fault planes
Sanchez, R., Chatellier, J-Y., de Sifontes, R., Parra, N.and Muñoz P., 1997,
Multiple Bischke Plots Analysis, a powerful method to distinguish between
- To help understand large folded complex structures in the tectonic or sedimentary complexity and miscorrelations; methodology and
absence of dipmeter data examples from Venezuelan oil fields, Memorias del Primero Congreso
Latinoamericano de Sedimentologia, Soc. Venezolana de Geologo, Tomo II,
Noviembre 1997, p.257-264
However it will not do the correlation for you nor will it give a solution
if the correlation is completely wrong.
Acknowledgements
It will however help identify zones which need revisions or help Thanks are given to Shell and to PDVSA, especially Carlos Porras for
define limits between areas of coherent stratigraphic correlation. allocating time to the author for investigating and revising the method
originally proposed by Dr Bischke. More particularly we would like to
thank Rick Carter, Taco van der Haart and Richard Bischke for their
The MBPA helps focus on the real problem, saving time and money. contribution to our understanding of the subject. Some of the diagrams
have been created using a spreadsheet designed by Taco van der Haart.