Abstract

This research study presents new concepts of the use of non-Darcian flow characteristics in reservoir characterization, description, development and well performance. More than thousand of core samples are analyzed under unsteady state flow conditions. A universal scale of turbulent factor versus permeability is developed based on the reference base-line of turbulent flow through metallic porous media.

This new scale is used:

  1. To classify reservoirs in terms of homogeneity and heterogeneity,

  2. To establish an isoturbulence map for improving reservoir development in terms of localization of adequate zones to drill new wells and to improve their performances.

Furthermore, a step-by-step methodology for selecting the best perforation characteristics is presented.

In this paper, different applications on Algerian reservoirs are outlined and a new concept of the use of turbulent factor is highlighted.

Introduction

This study develops aspects related to fluid flow through porous medium in turbulent flow regime. It comports a laboratory experimental analysis flowed by numerical and analytical simulation. Six reservoirs are selected: Upper Trias Shally Sand (TAGS/UTSS) of Hassi R'Mel, Lower Trias Shally Sand (TAGI/LTSS) of Ourhoud and Rhourd el Khrouf, and the Ordovicien of TFT, the Cenomanian Carbonate of Guerguet El Kihal South and the Cambrian of El Gassi and El Agreb fields.

Data related to these reservoirs are: production and core description. The flow of gas under pressure blow down or unsteady-state conditions is performed on 1600 core samples selected from cited reservoirs. In addition, artificial and homogeneous porous media represented by metallic plugs that are used for calibrating porosimeter and permeameter are used to provide a base-line of turbulent flow characteristics and to help the interpretation of turbulent flow through natural cores.

Turbulence factor versus permeability relationship is developed for each reservoir. Universal scale of these properties is established for improving reservoir characterization in terms of homogeneity and heterogeneity.

The first application is made on Hassi R'Mel and Rhourd El Khrouf reservoirs 1, and it is extended to more reservoirs (Sandstone and Carbonates). Layers of the same reservoir are also characterized in order to validate this scale. The result shows that this developed scale can be considered as a good tool for reservoir characterization.

The second application is used for the development of TFT reservoir and Well performance of Hassi R'Mel fields.

STUDY OBJECTIVES

On the basis of Jones 2 recommendation related to the possibility of the use of turbulence factor as an indicator of permeability heterogeneity, this study is developed to extend the initial research work 1 (R?f?rence CIPC 2002- 134), which predicts zones and layers that present high turbulence effect in the vicinity of production wells. Thus, the objectives are:

  • Integrating inertial factor in reservoir characterization by developing correlations and scales by which the inertial factor can be evaluated based on petrohysical properties.

  • Integrating these scales in reservoir development in order to characterize reservoirs in terms of permeability, to predict zones of high and low turbulence effects and to recommend where new wells can be drilled.

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