Abstract

The purpose of this paper is to emphasize that the taking, assembling andaveraging of the basic data for further use in an analysis of a reservoirrequires a profound knowledge of many of the specialized disciplines of moderngeology and petroleum engineering. The various aspects of " Static Data," aspresented in this paper, analyze that problem and specifically discuss the following major subheadings:

  • Porosity,

  • Permeability,

  • Facies Mapping,

  • Connate Water,

  • Relative Permeabilities and Capillary Pressures, and

  • Method of Least Squares.

This paper is essentially a generaland philosophical discussion on the necessity for obtaining data quality and ofthe need for an integrated approach to be applied in a detailed analysis of anyreservoir.

Introduction and Objectives

The correct taking, interpretation and usage of reservoir data are among themost important tasks of the petroleum engineer, and particularly of thereservoir engineer and geologist. On the quality, and to a much lesser degreeon the quantity, of this information depends the success as well as theaccuracy of all the subsequent geological and engineering studies and finallyof the economic evaluations. Despite this paramount importance, very little isfound on this subject either in petroleum literature or in universitycurricula. There are exceptions - e.g., the normal types of pressure build-upcurves and the determination of the areal and volumetric average pressures, without explaining when to use which and why. At the present stage of knowledgeof the science of reservoir physics, it appears that the analytical methods ofsolution (equations) are normally, from a mathematical and physical standpoint, much more exact than the basic data and particularly the averages which are fedinto them. In layman's terms, the reservoir analyst often performs an exactmultiplication of doubtfully reliable numbers. This lack of interest in theaccuracy and representativeness of the basic data and in the methods ofaveraging them is usually explained by the simplicity of this problem, whichcan be solved by " common engineering sense;" this explanation is correct if itis backed by a thorough and uniform theoretical, as well as practical, understanding of this complex problem.

This content is only available via PDF.