|Publisher||American Petroleum Institute||Language||English|
|Content Type||Conference Paper|
|Title||The Intensive Analysis of Oil-Field Cores|
|Authors||J. C. Calhoun, The Pennsylvania State University ;F. W. Preston, The Pennsylvania State University, ; C.R. Killins,The Pennsylvania State University|
|Source||Drilling and Production Practice, 1953|
|Copyright||1953. American Petroleum Institute|
An exact knowledge of the properties of the reservoir rock and its contained fluids is a basic requirement for good reservoir operation and prediction of performance, particularly in water flooding. The first quantitative data pertaining to reservoir rocks were obtained from the well samples taken by geologists. These were superseded by the more extensive samples obtained by well coring, and the determination of rock characteristics from these cores. More recently, coring has been supplemented by various well-logging methods. There is an attempt in some quarters to substitute well logging entirely. for coring and core analysis. Such attempts indicate a misunderstanding of the potential value of core analysis. Core analysis has passed far beyond the stage where it is used solely for porosity, permeability, and saturation determinations. It has entered the stage where routine measurements of capillary pressure and relative permeability are included. It can be extended even further. Core analysis properly includes all analytical tests which can be made on a rock sample and its contained fluids. Many such tests have been thought to be solely in the research realm. However, core analysis, if properly conducted, is itself research. Each new reservoir represents an unknown environment. The accumulation of core-analysis data represents research into the nature of this unknown environment. Therefore, the inclusion of the semi-research tests, or \"trouble-shooting\" analysis, is a proper part of core analysis. Core analysis can be intensified in many directions. Authors have discussed such intensification in terms of a statistical approach to interpreting core data;1 others have discussed the problem with respect to limestone cores.2 The scope of this paper is to discuss the intensification of core analysis in the direction of improved, expanded, or new test procedures, in the correlation of routine tests, and in the handling of cores for analysis. Illustrations cited are for a specific area, but it is believed that the general philosophy of a more intensive
The Use of Electrical Resistance Measurements
Resistance measurements on core samples can be used to much greater advantage than is current. For example, in two instances they have been used to indicate the degree of disturbance to which the fluids within the core have been subjected between the time the core was taken and that at which it was analyzed.
In these instances alternating samples of core were canned in fresh water, oil, and air. Each core, prior to canning, was placed between two electrodes and its resistance was measured. The electrodes were narrow brass strips placed lengthwise of the core at opposite sides of the core cylinder. The position of the electrodes was marked rapidly, and the core was canned. After these cores were brought into the laboratory, each was placed between electrodes which were duplicates of those previously used, at the position marked, and resistances were again measured.Table 1 is a list of the resistances of the cores before being canned at the well location and after being removed from cans in the laboratory.
|File Size||400 KB||9|