Developing and managing assets in an uncertain world presents a comprehensive survey of cuttingedge approaches used by industry to quantify the uncertainty in. Even though the results are more attractive running more than reservoir simulations on a large scale model. Uncertainty analysis of reservoir models ldi training. Engr 2600 modeling and analysis of uncertainty appreciation and understanding of uncertainties and the conditions under which they occur, within the context of the engineering problemsolving pedagogy of measurements, models, validation, and analysis. Click download or read online button to get geostatistical reservoir modeling book now.
Reducing the uncertainty of static reservoir model in a. These uncertainties stem from multiple sources and for most reservoirs cannot be eliminated. Reservoir model design available for download and read online in other formats. Validating reservoir models to improve recovery schlumberger. Production curve optimization is also necessary to ensure that maximum recovery is achieved for every well and reservoir. Geostatistical reservoir modeling download ebook pdf. Evaluating uncertainty in the volumes scholarlink research. The results always carry out a band of uncertainty 12282017 dr. After nearly 50 yr of production, an updated reservoir model was required for planning further development. A probabilistic workflow for uncertainty analysis using a. Modeling uncertainty in seismic imaging of reservoir structure satomi suzuki1, jef caers1, robert clapp2 and biondo biondi2 1department of petroleum engineering, stanford university 2department of geophysics, stanford university 1. Pdf uncertainty analysis in reservoir characterization and. This page topic builds on this with more details of how to approach uncertainty analysis as part of creating production forecasts.
In addition, the author discusses the role of uncertainty analysis in the static model and its impact on volumetric estimation. Introduction exploration and production of hydrocarbons1 is a highrisk venture. Conclusion if 3d modeling is now well established as a central piece of an integrated study, the systematic quantification of 3d uncertainties is quite new in our industry. Uncertainty analysis and reservoir modeling pdf bitbin. The understanding of uncertainties involved in reservoir modeling is an essential tool.
Uncertainty modeling and analysis in engineering and the sciences presents a holistic view of understanding uncertainty in systems that are of relevance to engineers and scientists in practice, in a more generalized approach, and is a useful book that provides a fundamental understanding to analyzing uncertainty in engineering and scientific. Uncertainty analysis of flow performance predictions involves identifying significant. A geological uncertainty study was initiated to identify and quantify the input parameters of greatest impact in the reservoir model. Wireline logging provides various recordings of subsurface formation properties and well logs are the main sources for petrophysical analysis. The methodology includes using multiple faulted geocellular models s grids covering a range of uncertainty in input parameters with multiplepoint statistical simulation faciesbased modeling, combined static and dynamic experimental design, probabilistic history matching, and use of model building and analysis automation tools. Developing and managing assets in an uncertain world presents a comprehensive survey of cuttingedge. Application of quantitative seismic geomorphologic. Download pdf geostatistical reservoir modeling free. Uncertainty analysis is an integral part of reservoir modeling process to capture various uncer. All assessments are subject to the risk of limited data, sometimes from only a single well. A new procedure to reduce uncertainties in reservoir simulation models using statistical inference and observed data is presented in this paper. Uncertainty is a function of our state of knowledge.
The text puts the focus on geostatistical modelling of facies and heterogeneities that constrain the distribution of reservoir properties including porosity, permeability and water saturation. Uncertainty can be modeled, but there is no objective measure of uncertainty. Uncertainty analysis and reservoir modeling aapg store. That is, uncertainty in the reservoir characterization and modeling is caused by theuncertainty inthe inputdataand uncertaintyinthe inference, as shown in figure 1. Engr 2600 modeling and analysis of uncertainty acalog acms. Uncertainty analysis and reservoir modeling request pdf. To initialize a reservoir simulation model, the initial oil, gas and water pressure distribution and initial saturations must be defined in the reservoir model.
Geologic modeling and uncertainty analysis of a gulf of mexico reservoir yuhong liu. Gregory zimmerman, 2011, geologic modeling and uncertainty analysis of a gulf of. Numerous channels and larger incised valleys can be found in the pliocene and pleistocene reservoir intervals of the northern gulf of mexico. A probabilistic workflow for uncertainty analysis using a proxybased approach applied to tight reservoir simulation studies. Modeling uncertainty in seismic imaging of reservoir structure. Uncertainty propagation during integrated reservoir modelling of. In addition, the author discusses the role of uncertainty analysis in the static model and. Uncertainty and risk analysis in petroleum exploration and. Petrophysical analysis is critical in a reservoir study because it provides a primary source of input data for integrated reservoir characterization and resource evaluation. All geostatistical methods used in estimation of reservoir parameters are inaccurate, modeling of estimation error in form of uncertainty analysis is very important. Reservoir uncertainty assessment using machine learning. Request pdf uncertainty in reservoir mod eling uncertainty is due to incomplete and imprecise knowledge as a result of limited sampling of the subsurface heterogeneities. In doing this, it serves the same purpose for the next generation of pestlike software. Reservoir simulation model initialization and validation reservoir simulation model initialization.
In addition, the manuscript suggests criteria for deciding when a quantitative analysis of uncertainty is necessary and when such analyses may not be necessary. It is best to use the simplest model which can meet the study objectives. In fact, this methodology provides a quantified decisionbased plan for minimizing risk in oil reservoirs kloosterman et al. Case example and workflow implementation 18 estimation of prediction uncertainties 1. Estimation of prediction uncertainties in oil reservoir simulation using bayesian and proxy modelling techniques part i. Asnul bahar introduction uncertainty analysis is an integral part of reservoir modeling process to capture various uncertainties that influence the quality and accuracy of a reservoir model. Consequently, the application of sensitivity analysis on stochastic models of reservoir horizons, petrophysical properties, and oilwater. Geological concepts are uncertain with respect to structure, reservoir seal, and hydrocarbon charge. Download pdf reservoir model design book full free. Reservoir simulation models in production forecasting. Reservoir uncertainty assessment using machine learning techniques jincong he abstractpetroleum exploration and production are associated with great risk because of the uncertainty on subsurface conditions. Reservoir simulation aspects uncertainty simulation has inherent uncertainties. With the help of the resgrid, a reservoir engineer can transparently take advantage of grid resources and services for computeintensive and dataintensive uncertainty analysis as well as enforce the understanding of multiphase reservoir modeling. Pdf uncertainty analysis of a co2 sequestration project.
Uncertainty analysis and risk management in reservoir. Uncertainty modeling and analysis in engineering and the. The hydrologic model parameters are selected here as the source of uncertainty propagation in the hydro. Since all geostatistical methods used in estimation of reservoir parameters are inaccurate, modeling of estimation error in form of uncertainty analysis is very important. Developing and managing assets in an uncertain world. Uncertainty range in production forecasting gives an introduction to uncertainty analysis in production forecasting, including a prms based definition of low, best and high production forecasts. The quantification of uncertainty in reservoir management. Uncertainty analysis in reservoir characterization m96. Observed data is used to guide the obtainment of posterior probability density functions pdf. Uncertainty assessment in 3d reservoir modeling an integrated approach uncertainty is not an inherent feature of our reservoirs. For the static reservoir uncertainty analysis, three scenarios are done a. Pdf a reservoir is the result of geologic processes and is not randomly generated. Uncertainty analysis and modeling to analyze uncertainty in reservoir characterization and modeling, it is convenient to put it under the framework of a scientific process. Uncertainty analysis is an integral part of reservoir modeling process to capture various uncertainties that influence the quality and accuracy of a reservoir model.
These type of models include but are not limited to petroleum and geothermal reservoir models, groundwater models and surface water hydraulic and hydrologic models. Our prior beliefs change as we compare the model output with the observed data. This work critically examines the foremost statistical reservoir uncertainty analysis approaches, the current probabilistic and stochastic uncertainty modelling workflows which are typically based on various numerical models, and the very recent development of embedding some artificial intelligence algorithms which include genetic algorithms. The benefits of using realistic 3d models for reservoir uncertainty quantification. Apply optimization to the forecast to select the optimum. Quantification of uncertainty in reservoir simulation performance. Estimation of prediction uncertainties in oil reservoir. Additionally, the events considered for reservoir analysis are commonly extreme events, adding to the analysis difficulty and uncertainty. The permeability simulation based on facies and the cloud transform between porosity and permeability allows better control across the reservoir of spatial connectivity patterns that could be used for improved reservoir performance prediction as carried out in the present static model. Reservoir geometry and dimensions the geometry and dimensions of the reservoir influence the selection of the model grid. A new procedure to reduce uncertainties in reservoir models. Workflow used in the gridbased geologic modeling and uncertainty. Prediction under uncertainty in reservoir mod eling mike christie1, sam subbey1.
Uncertainty analysis and reservoir modeling in searchworks. Such a decision making includes buyingselling the field, wherewhen to drill wells, how much oil should be. If the reservoir is small and vertical and areal effects are important, it may be possible to use a fullfield 3d model. Modeling rift basins uncertainty analysis in basin modeling evolution of normal faults. Use historyconditioned simulation models as a basis for forcasting single field development 3. In this study, one variable at a time design is used. Like many other exploration and production activities, uncertainty and risk in developing shale gas reservoirs are quite significant. Multiple reservoir models are generated, all honouring both static and dynamic data in the historic period. Although many reservoir characterization efforts have been made to help understand shale gas reservoirs, a systematic reservoir modeling based approach appears lacking in. Integrated shale gas reservoir modeling uncertainty.
A probability distribution always sums up to 1 100%, stating that one of the outcomes covered on the xaxis will certainly come true. On the other hand, economic evaluations have uncertainties related to costs. Coping with uncertainties through an automated workflow for 3d. Understanding the impact of those uncertainties on the production performance is. Quantification of conceptual and parametric uncertainties in fractured reservoir models paul r.
Geostatistics has played an increasing role in both groundwater hydrology and petroleum reservoir characterization and modeling, driven mainly by the recognition that heterogeneity in petrophysical properties i. However, many uncertainties exist in reservoir characterization. Developing and managing assets in an uncertain world presents a comprehensive survey of cuttingedge approaches used by industry to quantify the uncertainty in both conventional and unconventional reservoirs. Uncertainty analysis addresses fidelity and is used in different phases of an experiment, from initial planning to final reporting attention is needed to ensure uncertainties do not invalidate your efforts in propagating uncorrelated errors from individual measurement to final result, use the square root of the sums of the squares. Almost all the data used in reservoir simulation are subject to uncertainty. Introduction the modeling of structurally complex reservoirs is one of the most difficult tasks in reservoir modeling. Judy creek is a large carbonate reservoir in the giant swan hills oil field, located in alberta, canada. Petrel uncertainty enables the quantification of not only geophysical and geological uncertainties but also time and pressurebased reservoir uncertainties to provide comprehensive coverage of the quantification of the incertitude. In bayesian analysis, the posterior probability distribution characterizes the uncertainty in. Uncertainty analysis in creating production forecast. Keywords uncertainty, risk analysis, decision analysis, portfolio. The behaviour of the resulting simulation models can then indicate the associated level of economic uncertainty. While the uncertainty related to mappingquantification of hydrocarbons initially in.
Experimental design method distributes the simulation runs within uncertain ranges of parameters efficiently, thereby minimizes the number of required runs for studying an uncertain system steppan et al. Our approach data integration, risk assessment and quantification of uncertainty are key issues in petroleum exploration and development. Uncertainty analysis in reservoir characterization. Uncertainty analysis in reservoir characterization and management 7 risk apparently refers to vari ability markowitz, 1991, p. Perform a sensitivity analysis of a black oil simulation model using reservoir parameters that allow the final selection for an assisted history match process using cmost. Elf exploration production has developed a unique set of tools. Uncertainty analysis in reservoir characterization and.
Uncertainty analysis in predictive reservoir simulation using. The purpose of this document is to present, in one place, the theory that underpins pest and that underpins the plethora of utility software that supports and complements pest. This site is like a library, use search box in the widget to get ebook that you want. In this chapter, we discuss reservoir modeling and uncertainty evaluation of judy creek. For this purpose, first an uncertainty assessment method is introduced that evaluates the uncertainty associated with the hydroclimate processes. Reservoir simulation is used to forecast oil and gas production profiles under selected development scenarios. In reservoir uncertainty analysis one tries to quantify this ambiguity in order to assess the. The construction of the reservoir model and the implementation of the uncertainty analysis were. As each of these steps involves uncertainty, the resultant petrophysical data will have uncertainty and limitations. Pdf reservoir model design download full pdf book download. Constraining uncertainty in static reservoir modeling. To optimize the development plan for an underdeveloped reservoir associated with many uncertain parameters and subjected to this method of enhanced oil recovery, it is necessary to determine the effect of uncertain parameters on the behavior of the oil reservoir.
Uncertainty analysis and risk management in reservoir engineering. Learn sensitivity analysis, history matching, optimization, and uncertainty assessment techniques and their applicability in a black oil simulation model using imex. Such analyses are orders of magnitude faster than one using. Uncertainty quantification and sensitivity analysis of. This presentation covers only the static part of the modeling and uncertainty integrated workflow of a global. Integrated reservoir modeling reservoir management integrated reservoir modeling reservoir models a reservoir model is a mathematical representation of a specific volume of rock incorporating all the characteristics of the reservoir under study. Field development using compositional reservoir simulation. Errors and uncertainties in reservoir performance predictions. In addition, the program outputs the production data in a format. Integrated reservoir modeling of a pinedale tightgas reservoir in the greater green river basin, wyoming y. Even if the set of models all honour the same data measurements, there is still significant uncertainty in the production forecast.
This data was then implemented into a 3d numerical reservoir simulator cmggem, first to confirm pvt output in a compositional simulation cmgwinprop, then to simulate up to 20 years of production, and finally to use uncertainty analysis cmgcmost to optimize reservoir input parameters. It reveals that, depending on how the solution is going to be used. The text also addresses some typical approaches to modelling specific reservoirs. Uncertainty analysis of reservoir models featuring the application of workflow editor dr. The continuous probability density function right says, roughly, that values below zero are more likely than values above it, but that values around zero and slightly below are the most likely. Zee, 2011, uncertainty analysis in reservoir characterization and management. Principal component analysis is used to display the sets of realizations into the joint space of uncertainty of the response variables effective permeability, times to reach 5% and 95% water cuts. This uncertainty may be quite large, as is usually the case for the distribution of rock properties porosity and permeability away from the wells. In recent years, immiscible gas injection, as an effective method for enhanced oil recovery, has been used in many oil reservoirs. Constraining uncertainty in static reservoir modeling search and. Pdf uncertainty analysis in reservoir characterization. Fortunately, using 3d models as the basis for reservoir uncertainty quantification is now feasible due to advances in hardware and the development of reservoir modeling packages. These reservoir variables are typically not directly measured by welllogging tools. How can we manage risk and subsurface uncertainty in upstream.
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