Use of Discrete Fracture Network "DFN" to Characterize and Model a Naturally Fractured Sandstone Reservoir: A Case Study of Orocual Field, San Juan Formation, Venezuela

Fracture Modeling is a multi-step process involving several disciplines within reservoir characterization and simulation. This note applies Discrete Fracture Network (DFN) concept in a unique and comprehensive study of fracture modeling in one of the naturally fractured carbonate reservoir in Iran. A Discrete fracture network is a group of planes representing fractures. Fractures of the same type that are generated at the same time are grouped into a fracture set. Each fracture network containing fractures has at least one fracture set but may have many. The simplest fracture sets are defined deterministically as a group of previously defined fractures, either as a result of fault plane interpretation extraction from a seismic cube, or as previously defined fractures. Fractures modeled stochastically can be described statistically either using numerical input or properties in the grid. These properties can vary in 3D and can easily be modeled using seismic attributes from seismic data. Seven seismic attributes are used in this study. The final results of both deterministic and stochastic DFN modeling upscaled to a simple model and used as base grid in dynamic simulation. Introduction Anisotropy and heterogeneity in reservoir permeability present unique challenges during the development of hydrocarbon reserves in naturally fractured reservoirs. Over the history of naturally fractured reservoir development, many methods have been employed for characterization of fracture systems and their effect on fluid flow in the reservoir. These include the use of geologic surface outcrop analogues, core, single and multi-well pressure transient analysis, borehole imaging logs, and surface and borehole seismic observations. This study focuses on integration of fluid flow simulation and seismic attributes technology for improved prediction of fractured reservoir performance.

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An Investigation of Gas Recycling in Fractured Gas-Condensate Reservoirs

Temizel¹,

Kirmaci

Tiwari

et al. 2016

Day 1 Mon, November 07, 2016

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Condensate banking results from a combination of factors including fluid properties, formation flow characteristics, and pressures in the formation and wellbore. The production performance may suffer provided these factors are not understood at the beginning of field development. Determining the fluid properties can be vital in any reservoir, hence it plays a crucial role in gas-condensate reservoirs where condensate/gas ratio is significant in estimates for the sales potential of gas and liquid. Once reservoir fluids enter a wellbore both temperature and pressure conditions may change, where condensate liquid can be produced into the wellbore but liquid can also drop out within the wellbore. If the liquid falls back down the wellbore, the liquid percentage will increase and may eventually restrict the production. Thus, it is very important for robust reservoir management that each and every control and uncertainty parameter is understood not only in theory but also in practice with solid examples as done in this study. A robust commercial optimization and uncertainty software is coupled with a full-physics commercial simulator that models the phenomenon so as to investigate the significance of major parameters on performance of gas-condensate reservoirs under recycling. Control and uncertainty variables have been investigated via several simulation runs in specified ranges to represent real reservoir and performance conditions rather than theoretical assumptions. This study aims to prepare an insight into the mechanism of gas injection process in reducing gas-well productivity losses due to condensate blockage in the near wellbore region. The main goal of this work is to investigate gas recycling into the reservoir to enhance condensate recovery. The results show the influence of each control or uncertainty variable, leading to a better understanding of management of gas-condensate reservoirs under gas recycling. Impact of fractures is significant and the tornado diagrams illustrate the relative significance of each factor. The results and sensitivities are compared and discussed in light of a comprehensive literature review of recycling gas-condensate reservoirs with different process optimization methods. The significance of all major parameters are outlined using tornado charts to serve as a practical example for optimization of relevant future applications.

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Use of Discrete Fracture Network "DFN" to Characterize and Model a Naturally Fractured Sandstone Reservoir: A Case Study of Orocual Field, San Juan Formation, Venezuela

Cited by 5 publications

References 4 publications

Investigation of rock properties distribution effect on pressure transient analysis of naturally fractured reservoirs

Investigation of rock properties distribution effect on pressure transient analysis of naturally fractured reservoirs

Deterministic versus Stochastic Discrete Fracture Network (DFN) Modeling, Application in a Heterogeneous Naturally Fractured Reservoir

An Investigation of Gas Recycling in Fractured Gas-Condensate Reservoirs

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