Naturally fractured reservoir an overview sciencedirect topics. The behavior of naturally fractured reservoirs onepetro. Naturally fractured reservoirs geo55 inhouse request or enquiry. Formation evaluation of naturally fractured reservoirs. Hydraulic fracturing of naturally fractured reservoirs. Numerical simulation of coning in naturally fractured reservoirs. Bunger csiro earth science and resource engineering ian wark laboratory melbourne, victoria, 3168, australia, rob. Many reservoirs contain a network of interconnected, naturally occurring fractures, which provide most of the reservoirscale permeability. Recognizing naturally fractured reservoirs petrowiki. Numerical simulation of coning phenomena in naturally. Ideally, we should consider different reservoir concepts encapsulated in a large ensemble of reservoir models to quantify the impact of these and other geological uncertainties. Formation evaluation of naturally fractured reservoirs author roberto aguilera link web page. Get your kindle here, or download a free kindle reading app. The purpose of this collection of 15 papers is to introduce the subject of naturally fractured reservoir characterization to engineers interested in gaining a basic overview of the technology and its.
This paper is a followup to a previous article dealing with advances in the study of naturally fractured reservoirs l. This course covers geologic concepts, methodology, and technology used to characterize, evaluate, and manage naturallyfractured reservoirs. Flow diagnostics for naturally fractured reservoirs earthdoc. In fractured reservoirs viscous displacement often fails. But for the case of naturally fractured reservoirs, a small amount of research has been done on the determination of well drainage area and shape. Discretization and gridding in reservoir simulation 2. There are many logging tools and many methods that can be used for detection and evaluation of naturally fractured reservoirs see aquilera. In fact, it has been estimated that about 40% of the worlds known reserves reside in naturally fractured reservoirs. The distribution of fractures is highly uncertain in naturally fractured reservoirs nfrs and may be predicted by using the assistedhistorymatching ahm that calibrates the reservoir model according to some highquality static data combined with dynamic production data. Naturally fractured reservoirs exist throughout the world and represent significant amounts of oil and gas reserves, water, and other natural resources on earth. Geologic analysis of naturally fractured reservoirs. The productivity and development of naturally fractured reservoirs are mainly affected by the fracture net configuration. The type i, ii, iii and iv fractured oil reservoirs have an average ultimate recovery factor of 26%. Pdf characterization of naturally fractured reservoirs.
In the past halfcentury, the study of fluid flow and transport processes in fractured porous media has received great attention and has been one of the most active areas in. Recovery factors and reserves in naturally fractured. In this paper, however, we focus here on the influence of fracture aperture distribution. Reservoir characterization for naturally fractured reservoirs. Pdf introduction to naturally fractured reservoirs researchgate. Geologic analysis of naturally fractured reservoirs 2nd edition. Naturally fractured reservoirs and their link to tight and. This presentation is an introduction to naturally fractured reservoirs for subsurface students and professionals in the. Fracture network connectivity and aperture or conductivity distribution are two crucial features controlling flow behavior of naturally fractured reservoirs. Analysis of pressure transient tests in naturally fractured reservoirs. The challenge of estimating recovery from naturally. Naturally fractured reservoirs are elusive systems to characterize and difficult to engineer and predict. Geologic and engineering aspects of naturally fractured.
Fluid flow in naturally fractured reservoirs petrowiki. For naturally fractured reservoirs with a vertical fracture, the pressure behavior of wells crossed by a uniform flux and. Fundamental aspects and fieldscale practices appropriate methods should be employed to enhance the oil recovery from the naturally fractured reservoirs nfrs. A naturally fractured reservoir is comprised of complicated rock structure surrounded by irregular vug and natural fracture systems. Crains petrophysical handbook fractured reservoir basics. Naturally fractured reservoirs fluid flow in petroleum.
I am convinced significant volumes of hydrocarbons reside in naturally fractured reservoirs particularly in fields abandoned because of improper testing and evaluation or because the wells did not intersect the fractures. Problems related to naturally fractured reservoirs by adel. What appears to work in one might fail miserably in the next. The 8 fractured gas reservoirs have an average ultimate recovery factor of 61%. These reservoirs are challenging to operate because natural fractures are ubiquitous and there is a tendency for carbonate reservoirs to be oilwet or mixed wet. Download public course schedule 2020 download training portfolio registration policies data protection policy. There are a few limited methods to determine the drainage area of a well in naturally fractured reservoirs that have been presented in recent years. Spe member price usd 45 naturally fractured reservoirs present unique and specialized challenges to hydrocarbon extraction. Download the reservoir engineering aspects of fractured. Download for offline reading, highlight, bookmark or take notes while you read geologic analysis of naturally fractured reservoirs.
The use of conventional techniques has led to underestimating or overestimating recoveries and reserves in many naturally fractured reservoirs worldwide. This thesis presents an important step towards a deeper understanding of naturally fractured carbonate reservoirs nfcrs. In particular, it is intended for reservoir engineers who perform activities related to understanding nfr behavior and who use numerical simulation models for. Simulating water tracer test in naturally fractured. Reliable production forecasting for fractured carbonate reservoirs is a challenge. A naturally fractured reservoir nfr is a reservoir with a connected network of fractures created by natural processes such as diastrophism and volume shrinkage ordonez et al. Read free ebook now download geologic analysis of naturally fractured reservoirs second edition pdf free. Eclipse simulation of naturally fractured reservoirs this course is designed for reservoir engineers involved in the evaluation and management of naturally fractured reservoirs nfrs. As even the best analytical methods use some assumptions, numerical methods should be used for coning studies, especially in nfrs.
One of the candidates for enhancing the oil recovery from these reservoirs is the surfactantbased chemical flooding. An idealized model has been developed for the purpose of studying the characteristic behavior of a permeable medium which contains regions which contribute significantly to the pore volume of the system hut contribute negligibly to the flow capacity. Naturally fractured reservoirs may contain many fractures that permeate different regions of the reservoir, occurring with greater intensity near faults or folds. Naturally fractured reservoirs have been classified according to the relative contribution of the matrix and fractures to the total fluid production. Prediction of naturally fractured reservoir performance. This article is based on crains analyzing fractured reservoirs by e. Abstract chemical flooding in naturally fractured reservoirs. Determining how the fractures originated provides us with important clues for the areal and vertical distribution of fractures as well as a likely reservoir recovery.
Purchase geologic analysis of naturally fractured reservoirs 2nd edition. Nfr16 flow diagnostics for naturally fractured reservoirs summary. Geologic aspects of naturally fractured reservoirs the leading edge. Well production heterogeneity is a characteristic of most naturally fractured reservoirs. Reservoir fluid characterisation supplementary scripts used at the montanuniversitat up to the retirement. Van golfracht t 1982 fundamentals of fractured reservoir engineeringdevelopments in petroleum science, no. We model a twodimensional fractured reservoir in which the matrix is. Field examples and case studies demonstrate the importance of integrated geologic and. D degrees in petroleum engineering from the colorado school of mines. Two thirds of the oil reservoirs have recovery factors 20%, which is certainly high enough to be commercially attractive. If you are looking for one of the very good books regarding the reservoirs then you are going to need the book we are talking about. Naturallyfractured reservoirs the imperial college. Courses details for course naturally fractured reservoirs.
Controls on recovery factor in fractured reservoirs. At the same time, these reservoirs present some of the most daunting challenges the energy industry is faced with. Characterization of naturally fractured reservoirs. Geologic analysis of naturally fractured reservoirs ronald nelson geologists, engineers, and petrophysicists concerned with hydrocarbon production from naturally fractured reservoirs will find this book a valuable tool for obtaining pertinent rock data to. The behavior of naturally fractured reservoirs joi%warren p, j, rqot members aime abstract an idealized model has been developed for the purpose of studying the characteristic behavioroja permeable medium which contains regions which contribute sigizificantly to tbe pore volume o. Geologists, engineers, and petrophysicists concerned with hydrocarbon production from naturally fractured reservoirs will find this book a valuable tool for obtaining pertinent rock data to evaluate reserves and optimize well location and performance.
This course covers geologic and engineering concepts, methodology, and technology used to characterize, evaluate, and manage naturallyfractured reservoirs. Naturally fractured reservoirs nfrs are defined as reservoirs where fractures created by geological processes have a. Simulations of naturally fractured reservoirs onepetro. Naturally fractured reservoirs not only contain a significant share of the worlds hydrocarbon resources, they are also important to support the transition to a low carbon energy future, for example when producing low and highenthalpy geothermal heat or sequestering co 2. There are two models to simulate this kind of reservoirs. Coning studies in nfrs needs near wellbore modeling of multiphase flow in different directions for matrix and fracture systems. In that article i concentrated on types of fractures, how to intersect. Chemical flooding in naturally fractured reservoirs. Naturally fractured reservoirs aguilera, roberto on. It allows geologists and reservoir engineers to pragmatically understand the impact of fractures and their associated uncertainties.
It demonstrates the various kinds of discontinuities using geological evidence, mathematical kinematics model and computed tomography and uses this as a basis for proposing a new classification for nfcrs. The fractures serve as highly conductive flow paths for the reservoir fluid, increasing the reservoir s effective permeability significantly over that attributable to the rock matrix. Applications and limitations of geologic procedures and tools are discussed. Naturally fractured reservoir characterization seeks to confront many of these challenges by providing an introduction to the engineering and geological character of naturally fractured reservoirs. It is important to establish some basic criteria for recognizing when fractures are an important element in reservoir performance and to recognize the nature and performance characteristics of a naturally fractured reservoir. A new equation for the determination of a well drainage. Natural fractured reservoir engineering phdg textbooks in preparation, intended to be issued during 2015. Most of todays producing naturally fractured reservoirs were discovered accidentally. Do not copy or distribute in any form without explicit permission. These reservoirs are challenging to operate because natural fractures are ubiquitous and there is a tendency for carbonate reservoirs to be oilwet or mixedwet. Natural fractures, adverse wettability and complex matrix heterogeneity are all uncertain and can all negatively impact upon recovery.
Pdf the nature of naturally fractured reservoirs researchgate. To simplify this actual reservoir system, warren and root 1963 first presented the idealized system with an orthogonal set of cubic matrix blocks with intersecting fractures as shown in fig. Spe 84590 presented at the spe technical conference and exhibition held in colorado, 5 to 8 october. Geologic analysis of naturally fractured reservoirs 2nd. The high permeabilities of the fractures effectively short circuits the matrix blocks, making it difficult to establish sufficiently high pressure gradients to allow effective viscous displacement of the oil in the matrix a new important effect comes into play imbibition. Duc vietsovpetro vung tau city, vietnam paul gillespie david hunt hydro bergen, norway bingjian li ahmadi, kuwait richard marcinew. Pressure transient tests in naturally fractured reservoirs often exhibit nonuniform responses. Aguilera has presented his course on naturally fractured reservoirsand or render consulting services in more than 50 countries throughout the world. Fracaflow is the only package available on the market to provide all the necessary tools to assess fractured reservoirs, from secondary porosity assessment to permeability computation. The effect of connectivity on flow properties is well documented. Naturally fractured reservoirs present a production paradox. Eclipse simulation of naturally fractured reservoirs. Type 2 vs type 1 tectonic fractured reservoirs cenozoic asmari fields, zagros dual porosity reservoirs type 2 hydrocarbon storage capacity is given by micro and vuggy matrix porosity systems, whilst deliverability is provided by networks of fissures. Naturally fractured reservoirs, 2nd edition aguilera, dr.
Geomechanics, fluid dynamics and well testing, applied to. The focus is on understanding fractures in a reservoir how to. They include reservoirs with low hydrocarbon recovery. However, there are no panaceas, and tools and methods that work well in one reservoir can.
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