Reservoir Volume Determination
Authors: Stout John L. 
Published: December 2007

This paper was prepared for the 47th Annual Fall Meeting of the Society of Petroleum Engineers of AIME, to be held in San, Antonio, Tex., Oct. 8–11, 1972 Permission to copy is restricted to an abstract of not more than 300 words. Illustrations may not be copied. The abstract should contain conspicuous acknowledgment of where and by whom the paper is presented. Publication elsewhere after publication in the JOURNAL paper is presented. Publication elsewhere after publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is usually granted upon requested to the Editor of the appropriate journal, provided agreement to give proper credit is made. provided agreement to give proper credit is made. Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers Office. Such discussions may be presented at the above meeting and, with the paper, may be considered for publication in one of the two SPE magazines.

Abstract
Analysis of data used in reservoir studies is easily handled by advanced techniques of information management. Third party objectivity is an advantage in unitization studies where engineering calculations of participating interests are involved. The necessary tools are available in the form of computer programs, techniques of information management, and experience to provide the consistency, completeness, accuracy and economy required for a comprehensive reservoir study.
Essential in any reservoir study is the availability of digitized electronic well logs suitable for formation evaluation. Map and electric log display capabilities are also vitally important. Recent advances in these techniques include accurate representation of fault traces and faulted reservoir volumes, both superior to the old planimeter method.
An additional consideration of reservoir evaluation is the availability of an adequate data base for monthly production of crude and gas. The credibility of facts, their completeness and currency, are crucial to the integrity and over-all value of the study. The fact that such data has been carefully compiled and checked objectively tends to guarantee ready acceptance of the studies by the investors. Reports required by regulatory agencies can be prepared from these computational results. prepared from these computational results

Introduction
Systematic development of computer routines have advanced to the point where various modules for a total reservoir analysis are now available. Management of data including the original logs and formation evaluation techniques through mapping and display of the net reservoir sand is routine. This includes a preliminary reservoir study and determination of preliminary reservoir study and determination of hydrocarbons in place for the total volume of the reservoir complete through the final material-balance solution of the production history. These programs can be performed on reported information collected by state regulatory agencies. This is satisfactory for property evaluation and potential property property evaluation and potential property acquisition. More complete records may be supplied by a participant of a unit giving the complete evaluation suitable for decisions in unitization studies. Analysis of these data can be objectively handled by a third party observer giving credence to the objectivity of the data and possibly avoiding unnecessary delays in the final acceptance of percentage allocation. The ability to use tools such as computer programs and information management, as well as careful compilation and checking of the data by experienced third party interest, guarantees ready acceptance of the study results.