TY - THES

T1 - Carbonate Reservoirs and Estimation of Oil Production From Them With Special Focus on Decline Curve Analysis

AU - Yalcinoglu, Latif

N1 - no embargo

PY - 2007

Y1 - 2007

N2 - Carbonate rocks are characterized by extremely heterogeneous porosity and permeability. Since carbonate reservoirs contain more than 60% of the world oil reserves, studies on these rocks have been increasing to understand their complex nature. The objective of this work has been a literature search about the carbonate reservoirs, with special focus on the dolomite reservoir. This search includes geologic properties, production estimation and secondary recovery possibilities. Because of the complex nature of the carbonate reservoirs, reserve and production estimation is complicated. Decline curves belong to the most suitable methods. Decline curve method is heuristic and developed by Arps who introduced its empirical equations and extrapolation techniques. Afterwards, the theoretical background of some of these curves was improved by other researchers, e. g. Fetkovich and Li and Horne. While Fetkovichs decline curve method is applicable to all kind of reservoirs, Li and Horne decline curve method is suitable only for naturally fractured reservoirs. In this work, both of the methods are applied to a naturally fractured carbonate reservoir in using its production data. The satisfactory results are discussed. Usually, carbonate reservoirs are fractured and exhibit low matrix porosity and permeability. These properties make some of the conventional enhanced oil recovery methods inapplicable. Appropriate EOR methods, e.g. CO2 injection, polymer flooding, thermal EOR are reviewed in this study. The EOR project should be prepared considering all the properties of the respective carbonate reservoir.

AB - Carbonate rocks are characterized by extremely heterogeneous porosity and permeability. Since carbonate reservoirs contain more than 60% of the world oil reserves, studies on these rocks have been increasing to understand their complex nature. The objective of this work has been a literature search about the carbonate reservoirs, with special focus on the dolomite reservoir. This search includes geologic properties, production estimation and secondary recovery possibilities. Because of the complex nature of the carbonate reservoirs, reserve and production estimation is complicated. Decline curves belong to the most suitable methods. Decline curve method is heuristic and developed by Arps who introduced its empirical equations and extrapolation techniques. Afterwards, the theoretical background of some of these curves was improved by other researchers, e. g. Fetkovich and Li and Horne. While Fetkovichs decline curve method is applicable to all kind of reservoirs, Li and Horne decline curve method is suitable only for naturally fractured reservoirs. In this work, both of the methods are applied to a naturally fractured carbonate reservoir in using its production data. The satisfactory results are discussed. Usually, carbonate reservoirs are fractured and exhibit low matrix porosity and permeability. These properties make some of the conventional enhanced oil recovery methods inapplicable. Appropriate EOR methods, e.g. CO2 injection, polymer flooding, thermal EOR are reviewed in this study. The EOR project should be prepared considering all the properties of the respective carbonate reservoir.

KW - Carbonate

KW - Dolomite

KW - Naturally Fractured Reservoirs

KW - Decline Curve Analyses

KW - Fetkovich Type Curve Analyses

KW - Decline Curve Analyses

KW - Naturally Fractured Reservoirs

KW - Fetkovich Method

M3 - Master's Thesis

ER -