A reservoir simulation approach for modeling of naturally. Reservoir characterization for naturally fractured reservoirs. The focus is on understanding fractures in a reservoir how to. Pdf advances in the study of naturally fractured hydrocarbon. Behaviour of naturally fractured reservoirs re17 stephan k. The behavior of naturally fractured reservoirs including. Introduction the development of reservoir modeling and reservoir characterization for naturally fractured reservoirs nfrs has lagged behind simpler matrix flow dominated rock.
Characterization of naturally fractured reservoirs article pdf available in spe reprint series spe 69538 march 2001 with 1,474 reads how we measure reads. Aguilera, r naturally fractured reservoirs, pennwell. This publication deals exclusively with naturally fractured reservoirs, and includes many subjects usually treated in separate volumes. Spe 84590 presented at the spe technical conference and exhibition held in colorado, 5 to 8 october.
Controls on recovery factor in fractured reservoirs. Pdf naturally fractured reservoirs, within which porosity, permeability pathways andor impermeable. For these reservoir characteristics it is difficult to place a reasonable certainty of volumetric estimates of original hydrocarbonsinplace and reserves. Spe member price usd 45 naturally fractured reservoirs present unique and specialized challenges to hydrocarbon extraction. Petrophysical characterization of carbonate naturally.
Geologic and engineering aspects of naturally fractured. 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. Naturally fractured reservoirs 2nd edition free ebook download as pdf file. They are also notorious for early gas or water breakthrough. Therefore, naturally fractured reservoirs are termed as dual. They often comprise high permeable, low storage volume fractures, and tight, high storage volume matrix blocks. The challenge of estimating recovery from naturally. Pdf permeabilities and skins in naturally fractured reservoirs. Fracture propagation in naturally fractured reservoirs. They include reservoirs with low hydrocarbon recovery.
Carbonate naturally fractured reservoir is a multiporous system that contain microfractures, fractures, vugs, macrovugs, matrix, type of fractures network. Pdf though matrix and secondary porosity permeabilities of a naturally fractured reservoir are. Get pdf abstract 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. Introduction conventional reservoir engineering techniques and naturally fractured reservoirs do not mix well. Recovery efficiency in fractured reservoirs according to j. Naturally fractured reservoirs constitute a substantial percentage of remaining hydrocarbon resources. Pdf characterization of naturally fractured reservoirs. Fractured basement reservoir characterization for fracture. Problems related to naturally fractured reservoirs by adel. Because they must be incorporate into the numerical model of simulation the results of the petrophysical characterization, it is conceptualized like a. There are many logging tools and many methods that can be used for detection and evaluation of naturally fractured reservoirs see aquilera. Recovery factors and reserves in naturally fractured reservoirs.
In fractured reservoirs viscous displacement often fails. Oil recovery in fractured reservoirs arne graue, robert w. Calculate porosity partitioning coefficient of a naturally fractured reservoir calculate storage capacity and interporosity flow factor analyze well tests in naturally fractured reservoirs assess reservoir performance of horizontal wells in nfr use mbe to analyze impact of pressure depletion on recovery dr. Naturally fractured reservoir an overview sciencedirect topics. Numerical results show that d, the ratio of matrix system permeability to. Naturally fractured reservoirs are elusive systems to characterize and difficult to engineer and predict. Studies in naturally fractured reservoirs for improved eor. Well test analysis for fractured reservoir evaluation. Gilman, page 4 of 35 with all these issues, there may appear to. The problem is reduced to solving an integral equation. On the other hand, they represent some of the largest, most productive reservoirs on earth. Directional permeability has important applications to drawdown andor injection with regard to well placement, and eor. Fractures and open ings of large size form vugs and interconnected channels, whereas the fine cracks form blocksy5.
Natural fractures, which are part of the secondary porosity, can be classified as tectonic, regional, and diagenetic aguilera, 1988. However, there are no panaceas, and tools and methods that work well in one reservoir can. 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. Fractured reservoirs are not isotropic, and models of fluid movement must account for.
A good development strategy for such reservoirs requires accurate information on reserve in place. Reservoir characterization of fractured reservoirs in. Pressure response in a naturally fractured reservoir showing ideal dual porosity behavior. He held the title of senior research consultant for chevron energy technology company where he worked for 27 years on an array of international projects that included reservoir structural geology studies, consulting, technology development, training, and exploration. Purchase well test analysis for fractured reservoir evaluation, volume 27 1st edition. They found that water coning takes place in fractured porous medium with permeability up to 10 darcys in both good and poorly cemented wells. The best known attempts at simple continuum models are the dual porosity approaches for naturally fractured reservoirs aguilera, 1980. Well test analysis for naturally fractured reservoirs. This course covers geologic and engineering concepts, methodology, and technology used to characterize, evaluate, and manage naturally fractured reservoirs. Because they must be incorporate into the numerical model of simulation the results of the petrophysical characterization, it is conceptualized like a model of double porosity. Naturally fractured reservoirs present a production paradox.
In naturally fractured reservoirs, the matrix pore volume, therefore the matrix porosity is reduced as a result of large reservoir pressure drop due to oil production. Recognizing naturally fractured reservoirs petrowiki. The solution is straightforward, and involves only ordinary bessel functions. Naturally fractured reservoirs exist throughout the world and represent. Fractured basement reservoirs differ from other types of naturally fractured reservoirs in that they are generally considered to have no primary porosity le van hung et al. Hydraulic fracturing in tight gas and shale gas reservoirs is an essential stimulation technique for production enhancement. Jim has also been involved in training, consultation, and project work in reservoir engineering, reservoir simulation, naturally fractured reservoirs, horizontal wells and production uncertainty analysis. Fracture porosity of naturally fractured reservoirs onepetro.
Abstract due to complexity associated to petrophysical characterization of the porosity in naturally fractured reservoirs, a methodology to discretize it in four main systems was developed. Naturally fractured reservoirs fluid flow in petroleum. Fractured reservoirs the reservoir gasoil ratio, gor us. In naturallyfractured reservoirs, the derivative tends to show several stabilizations at different levels. Fractured reservoirs are not isotropic, and models of fluid movement must account for such heterogeneity. Evaluation of water coning phenomenon in naturally fractured. Field examples and case studies demonstrate the importance of integrated geologic and. The behavior of naturally fractured reservoirs joi%warren p, j, rqot members aime abstract. Naturally fractured reservoirs nfrs are defined as reservoirs where fractures created by geological processes have a significant impact on the migration, storage, and extraction of hydrocarbons table 5. Naturally fractured reservoirs nfrs have been studied intensively for several decades in the geologic and engineering fields and recently, two new approaches have been proposed to address the problem of transient pressure testing in naturally fractured reservoirs.
Get pdf abstract 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. He has served as senior technical consultant and manager for marathon oil company in. Depending on the selection of the radial flow regime, different well and reservoir models may be possible. It is written for students, reservoir geologists, log. Recovery the rate of pressure decline per unit of oil produced the absence of transition zones in a fractured reservoir pressure drop around a producing wellbore in a fractured reservoir is very low. A naturally fractured reservoir nfr has two different porosities and permeability.
Chapter 1 deals with geologic aspects of naturally fractured reservoirs, reasons for generations of fractures including tectonic, regional, contractio nal and surfacerelated fra ctures, migration and accumulation of petr61eum, direct and indirect sources of information. Coauthor of fractured reservoir analysis, an aapg school. 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. Castagna1 1university of houston 2schlumberger and 3delta geophysics received march 2012, revision accepted september 2012 abstract. This large pressure drop causes the fracture pore volume, therefore fracture porosity, to increase. Geologic analysis of naturally fractured reservoirs. Formation evaluation of naturally fractured reservoirs. Castagna1 1university of houston 2schlumberger and 3delta geophysics received march 2012, revision accepted september 2012. Simulation of naturally fractured reservoirs with simbestii. Textbook series natural fractured reservoir engineering. Studies in naturally fractured reservoirs for improved eor scott p. The use of the dualporosity approach for the modeling of naturally fractured reservoirs has become widely accepted in the oil industry.
Formation evaluation of naturally fractured reservoirs author roberto aguilera link web page. The most difficult problem after finding basement rock reservoirs is to evaluate. 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. The behavior of naturally fractured reservoirs onepetro. Seismic characterization of naturally fractured reservoirs using amplitude versus offset and azimuth analysis mehdi e. The focus is on understanding fractures in a reservoir how to determine whether fractures are important to hydrocarbon producibility, and if so. Naturally fractured reservoirs training course petroskills fr. Naturally fractured reservoirs have been classified according to the relative contribution of the matrix and fractures to the total fluid production. So talking about fractured reservoirs in general is not good enough. It is written for students, reservoir geologists, log analysts and petroleum engineers. A new method to estimate reserve in naturally fractured. How dual porosity reservoirs are modeled with modern numerical simulators and simulation exercises will. Seismic characterization of naturally fractured reservoirs.
The original idealized model assumes that the fracture is the primary conduit for flow, whereas the matrix acts. 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 applications. The challenge of estimating recovery from naturally fractured. Characterization of naturally fractured reservoirs digital. This course covers geologic and engineering concepts, methodology, and technology used to characterize, evaluate, and manage naturallyfractured reservoirs.
Wayne narr is a structural geologist with interest in characterization and modeling of naturally fractured reservoirs. Natural fractures exist practically in all reservoirs, dividing the reservoir rock in pieces, called matrix blocks. This behavior is observed particularly in reservoir where matrix porosity is. This course will cover the oil recovery mechanisms in fractured reservoirs, which undergo the waterflood or gas cap expansion and gas injection. An alternative analytical solution to the system of equations for fluid flow through a doubleporosity medium with a boundary condition of an equipotential surface is given in this paper. Naturally fractured reservoirs pdf free download epdf. The production of fluids from naturally fractured reservoirs has. Hydraulic fracturing in naturally fractured reservoirs and. 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. Applications and limitations of geologic and engineering procedures and tools are discussed.
Sun spe 84590 data obtained on the 100 fractured reservoirs examined in this study indicate that overall, their ultimate recoveries are somewhat lower than those of many conventional reservoirs, but they still compare favorably with some conventional reservoir types. The porosity of the matrix is the primary porosity, whereas secondary porosity is represented by fractures channels. Evaluation of water coning phenomenon in naturally. Naturally fractured reservoirs aguilera, roberto on. Characterization of naturally fractured reservoirs. Well production heterogeneity is a characteristic of most naturally fractured reservoirs. In naturally fractured reservoirs, the derivative tends to show several stabilizations at different levels. Practical aspects of simulation of fractured reservoirs 08012003 2003, james r. Most naturally fractured reservoirs i am familiar with are characterized by low matrix porosities less than 10% and low matrix permeabilities less than 1 md. 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. The same conclusion was reached earlier by odeh 1965 who studied several fractured reservoirs. Naturally fractured reservoirs nfrs are defined as reservoirs where. However, traditional rate transient analysis, a reserve estimation technique, is not suited for naturally fractured reservoirs. Roberto aguilera, 1995, naturally fractured reservoirs 2nd edition.
436 1301 620 38 1458 1221 276 367 1269 695 169 133 568 1454 646 308 168 575 716 809 1102 822 587 125 420 285 292 1075 622 936 549 1372 699 1087 994 329 709 881 505 651 228 778 89 1420 779 1351 486