A Computer File Of Oil Reservoir Fluid Property Data
Authors: Burger D.H. , Heidemann R.A. , Heidemann K. Aziz 
Published: March 2010

This paper describes a recently developed computer file for the data in conventional oil reservoir fluid study reports. The data from 107 studies conducted on samples taken from Alberta oil reservoirs were selected from the public files maintained by Alberta's Energy Resources Conservation Board and were transcribed to this file.

For each reservoir fluid study, data were grouped into several different types. A standardized computer record was designed for each type. Twenty different record types were used, each having a card image format to permit reading of the file from cards, tape or disc by the same FORTRAN programs.

The data were edited to find any transcription errors and to evaluate the internal consistency of the reservoir fluid study measurements. These consistency tests found that several of the reports on the file contained data of questionable accuracy. Based on the limited use of the data file, several recommendations are made regarding the conduct and reporting of fluid studies.

Various data on the files have been used in evaluating viscosity and phase-equilibrium correlating schemes.

Introduction

Volumetric and phase-behaviour data for petroleum reservoir fluids are used routinely by practicing petroleum engineers to estimate petroleum reserves, calculate reservoir withdrawals and conduct reservoir depletion studies. These data are also required to design improved oil and gas recovery schemes, wellbore flow systems, flow lines, separation and other fluid handling systems.

The industry has in the past 'relied on the data obtained by laboratory measurements conducted on a sample of reservoir fluid. The laboratory tests are intended to simulate typical conditions of an oil reservoir, or the combination of a reservoir and surface facilities, as nearly as is practical. However, actual depletion mechanisms may be quite different from those used in the laboratory.

For some time, researchers have been attempting to develop methods of performing vapour-liquid equilibrium calculations which are sufficiently accurate for reservoir fluid systems. However, only recently have the results been sufficiently accurate for complex naturally occurring mixtures at reservoir temperatures and pressures. There is now a need for comparative investigations of the accuracy of available techniques for the prediction of volumetric and phase-behaviour properties of reservoir fluids. The prerequisite for such studies is the development of a suitable data base for the testing of the various methods. This paper reports on the development of a computer file to serve as such a data base 6f reservoir fluid property data.

The data for the file were taken from reservoir fluid studies conducted on fluid samples obtained from Alberta's oil and gas reservoirs. As a result of the requirements of Alberta's Oil and Gas Conservation Regulations, copies of many such studies have been forwarded to the Energy Resources Conservation Board (ERCB), where they are filed and, subject to the ERCB's rules for release of information, are made available to the public. The ERCB's Conventional PVT Analyses Index (1976) lists nearly 1000 laboratory reports of conventional reservoir fluid studies conducted on samples taken from crude oil pools in Alberta.