Jean-Yves D. Chatellier¹, Carlos Porras²

(1) PDVSA Intevep, Caracas, Venezuela
(2) PDVSA Oriente, Puerto La Cruz, Venezuela

ABSTRACT: The Multiple Bischke Plot Analysis, a Simple and Powerful Graphic Tool for Integrated Stratigraphic Studies

Establishing the correct stratigraphy is not always a simple task, especially when dealing with tectonically complex areas or when tectonics was locally controlling the sedimentation. Bischke in 1994 introduced a simple technique to compare the gradual change in thicknesses in two wells, the difference being plotted against the reference well's depth. The MBPA (Multiple Bischke Plot Analysis), derived from the original method allows a very quick and objective review of the stratigraphy.

Because the MBPA invokes many wells at the same time, the problem well and the problem zone can be readily identified because the anomaly shows up in all paired well comparisons. One of the interests of the method is that it does not matter how many faults or folds are present between the wells under study as only disturbance within the wells will show up in the analysis.

Stacking several Bischke plots on the same diagram gives a different view of the coherency of the stratigraphy and of the structure. Thus trend similarity are more obvious than in the MBPA whereas local anomalies are less readily apparent.

The power and limitations of both methods will be demonstrated through a review of case examples from various parts of the world. Thus, the MBPA allows to quickly identify anomalies and to distinguish between faults of various types, unconformities, sequence boundaries or wrong correlations. The method does not solve the problem but allows geoscientists to focus their attention to the real problem be it a marker, a well or a geographic area.

AAPG Search and Discovery Article #90906©2001 AAPG Annual Convention, Denver, Colorado