Naturally fractured reservoir characterization digital edition. However, due to transit disruptions in some geographies, deliveries may be delayed. Naturally fractured reservoir characterization digital. The productivity and development of naturally fractured reservoirs are mainly affected by the fracture net configuration. Fracture porosity of naturally fractured reservoirs onepetro. Geologic analysis of naturally fractured reservoirs nelson, ronald on. Pdf reservoir characterization for naturally fractured reservoirs. In this example, we model a linedrive waterflood of the naturally fractured reservoir introduced in section. 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. Naturally fractured reservoirs are elusive systems to characterize and difficult to engineer and predict.
In naturally fractured tight gas reservoirs, gas is mainly stored in the rock matrix with very low permeability, and the natural fractures have the main contribution on total gas production. The complexity of fracture development stems from the interaction of natural and induced fractures where a. Spe 69538 characterization of naturally fractured reservoirs s. This course covers geologic concepts, methodology, and technology used to characterize, evaluate, and manage naturally fractured reservoirs. Introduction in this chapter the characteristics of a naturally fractured reservoir are considered. Geologic analysis of naturally fractured reservoirs covid19 update. Naturally fractured reservoirs present a production paradox. Two thirds of the oil reservoirs have recovery factors 20%, which is certainly high enough to be commercially attractive. Relate fracture density, aperture, and length to facies, lithology and digenesis determine fracture porosity and permeability in nfr calculate porosity partitioning coefficient of a naturally fractured reservoir calculate storage capacity and interporosity flow factor analyze well tests in naturally fractured reservoirs.
Geologic analysis of naturally fractured reservoirs. Oil recovery in fractured reservoirs arne graue, robert w. A more accurate but also more expensive procedure is to combine a discrete fracture. Recognizing naturally fractured reservoirs petrowiki. The models are solved by utilizing laplace transformation and orthogonal transformation, and flow rate of the well is calculated by coupling the two models. Naturally fractured reservoirs not only contain a significant share of the worlds. Streamlinebased production data integration in naturally fractured reservoirs. The most difficult problem after finding basement rock reservoirs is to evaluate.
A new procedure for history matching naturally fractured reservoirs. How dual porosity reservoirs are modeled with modern numerical simulators and simulation exercises will also be. Geologic analysis of naturally fractured reservoirs 2nd edition. Reservoir characterization and simulation modeling of naturally fractured reservoirs nfrs presents unique challenges that differentiate it from conventional. Injectorproducer pairs can be used to help recover oil from a naturally fractured reservoir. Hydrocarbon production from fractured basement formations introduction this is a compilation of publicdomain information about commercial hydrocarbon reservoirs in fractured crystalline basement formations from approximately 30 different countries. Well production heterogeneity is a characteristic of most naturally fractured reservoirs. Naturally fractured reservoirs contain a significant portion of global. Therefore, identifying natural fractures characteristics in the tight formations is essential for well productivity evaluations. A fractured reservoir is one in which naturally occurring fractures either have or are predicted to have a significant effect on reservoir fluid flow in the form of 1 increased reservoir permeability, 2 increased porosity, andor 3 increased permeability anisotropy.
Reservoir characterization for naturally fractured reservoirs. 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. Fractured basement reservoir characterization for fracture distribution, porosity and permeability prediction marie lefranc. For fractured reservoirs, obtaining the right data and forecasting the reservoir performance is much more difficult than for conventional reservoirs. It allows geologists and reservoir engineers to pragmatically understand the impact of fractures and their associated uncertainties. Gilman, page 4 of 35 with all these issues, there may appear to be little hope of getting a unique answer. Evaluation of water coning phenomenon in naturally fractured oil reservoirs reda abdel azim1 received. In order to predict productivity of multiple fractured horizontal well in fractured reservoir, flow models of reservoir and hydraulic fractures based on the volumetric source idealization are developed. Most wells completed in newly discovered fractured reservoirs produce at high ip. This webpage version is the ed intellectual property of the author. Applications and limitations of geologic and engineering procedures and tools are discussed.
To investigate the boundary condition dependency of shape factor, the diffusivity equation is solved analytically in laplace domain for different depletion regimes in the fracture including. Prediction of naturally fractured reservoir performance using novel integrated workflow reda abdel azim chemical and petroleum engineering department american university of ras al khaimah ras al khaimah, united arab emirates abstractgeneration of naturally fractured reservoir subsurface fracture maps and prediction its production potential. This course will cover the oil recovery mechanisms in fractured reservoirs, which undergo the waterflood or gas cap expansion and gas injection. Natural fractured reservoir engineering phdg textbooks in preparation, intended to be issued during 2015. When properly analyzed and integrated with novel approaches often reveal key information to understand the these studies architecture and geoplumbing of fractured reservoirs in the subsurface. The behavior of naturally fractured reservoirs onepetro. Combining outcrop studies and numerical modelling tools we improve our ability to predict mechanic and flow behaviour of subsurface sediments. Numerical results show that d, the ratio of matrix system permeability to. The challenge of estimating recovery from naturally. Geologic and engineering aspects of naturally fractured. This statement is very well supported by a reservoir modeling study reported by phelps and strauss 2002.
It is a crosssection model with four rock matrix layers and four horizontal fracture layers. 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. A number of the selected manuscripts focus on outcrop analogues. The flow material balance method is applicable only when the flow reaches boundarydominated flow period. Pdf characterization of naturally fractured reservoirs gustavo. Pdf naturally fractured reservoirs present a production paradox. Evaluation of water coning phenomenon in naturally fractured. In fractured reservoirs viscous displacement often fails. Naturally fractured reservoirs in the ukcs tim wynn agr tracs 20 may 2018 1. Practical aspects of simulation of fractured reservoirs 08012003 2003, james r. Applications and limitations of geologic procedures and tools are discussed. Intermediateadvanced course objectives and description this course is designed for geologists, geophysicists and reservoir engineers who are part of. Fractured carbonate reservoirs american association of.
Boundarydominated flow an overview sciencedirect topics. Geologic analysis of naturally fractured reservoirs 2nd. Naturally fractured reservoirs present unique and specialized challenges to hydrocarbon extraction. Pdf the nature of naturally fractured reservoirs researchgate. Enhanced oil recovery in fractured reservoirs 91 capillary pressure curve, or more accurately, the positive part of the imbibition capillary pressure curve. The challenge of estimating recovery from naturally fractured reservoirs. Fractured basement reservoir characterization for fracture. We will overestimate fracture permeability if we ignore rugosity, tortuosity and continuity. In this case, the flow reaches a steady or pseudosteady state, and the pressures at all points of the reservoir drops at an identical velocity, as shown in figure 9. Journal of chemical and petroleum engineering, university.
In type 1 reservoirs, fractures provide the essential reservoir storage capacity and permeability. This course covers geologic and engineering concepts, methodology, and technology used to characterize, evaluate, and manage naturally fractured reservoirs. On the other hand, they represent some of the largest, most productive reservoirs on earth. This reservoir rock is mostly carbonate and it was proven that there are extended fracture networks through the reservoir. Nelson 1 identifies four types of naturally fractured reservoirs. Typical type1 naturally fractured reservoirs are the amal field in libya, edison. 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. Fractures are the most abundant visible structural features in the earths upper crust. Crains petrophysical handbook fractured reservoir basics. The 8 fractured gas reservoirs have an average ultimate recovery factor of 61%. Prediction of naturally fractured reservoir performance using. This article is published with open access at abstract water coning is a complex phenomenon observed in conventional and unconventional.
State of the art part 1 physical mechanisms and simulator formulation. I combine the elastic properties of fractured rocks and the reflectivity formulas in anisotropic media to derive the relationship between pwave amplitude anisotropy and fracture physical properties. Pdf use of fractured reservoir simulators can help reservoir engineers in the understanding of the main physical mechanisms and in the. How dual porosity reservoirs are modeled with modern numerical simulators and simulation exercises will also be covered. Characterizing natural fractures productivity in tight gas.
Effective models of fractured systems stanford earth. Discretization and gridding in reservoir simulation 2. Evaluation of water coning phenomenon in naturally. The type i, ii, iii and iv fractured oil reservoirs have an average ultimate recovery factor of 26%. 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 training course petroskills fr. Prediction of naturally fractured reservoir performance. Chapter 2 naturally fractured reservoirs sciencedirect. 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. Do not copy or distribute in any form without explicit permission. Gilman, page 4 of 35 with all these issues, there may appear to.
The focus is on understanding fractures in a reservoir how to determine whether fractures are important to hydrocarbon producibility, and if so. They are also notorious for early gas or water breakthrough. Fractured reservoirs distributed fractures, faults and folds have a profound impact on the geometry of sedimentary bodies and their physical behaviour, from mechanics to flow. They include reservoirs with low hydrocarbon recovery. They are apparent at most rock ridges, and it is likely that most reservoirs contain some natural fractures. Controls on recovery factor in fractured reservoirs. The influence of fracture closure from petroleum production from naturally fractured reservoirs. Introduction the development of reservoir modeling and reservoir characterization for naturally fractured reservoirs nfrs has lagged behind simpler matrix flow dominated rock. 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. P lemonnier and b bourbiaux simulation of naturally fractured reservoirs. Combine your geoscience knowledge with new technology, both on the data acquisition side fly that drone. 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.
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 solution is straightforward, and involves only ordinary bessel functions. Drones and dronederived digital data are the hottest growth areas around. Naturally fractured dualporosity reservoirs are usually idealized as a set of uniform. A new model to predict productivity of multiplefractured. However, due to the low matrix permeability and complexity of the formation in naturally fractured tight gas reservoirs, welltest data are affected by long wellbore storage effect that masks the reservoir response to pressure change, and it may fail to provide dualporosity dualpermeability models dynamic characteristics such as fracture. Moe and thomas bogno department of physics, university of bergen, norway abstract visualization of the effects of various wettability conditions on oil recovery in fractured reservoirs is demonstrated in twodimensional insitu imaging experiments in large blocks of. The problem is reduced to solving an integral equation. Naturally fractured oil reservoir c c is a naturally fractured oil reservoir in south west of iran. We can also see that the change in average pressure of reservoir equals to the change in bottom hole flowing pressure bhfp. The behavior of naturally fractured reservoirs including.
The shape and ra nge of the positive capillary pressure curve is dictated by the wettability. Purchase geologic analysis of naturally fractured reservoirs 2nd edition. Naturally fractured reservoirs differ from homogeneous reservoirs from many points of view. Naturally fractured reservoirs have been classified according to the relative contribution of the matrix and fractures to the total fluid production. Textbook series natural fractured reservoir engineering. 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.
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