The true value of a quantity is related to the mean of several measurements by. Barton smeal college of business administration the pennsylvania state university 406 business building university park, pa 16802, usa barry l. A comparison of the deterministic and probabilistic methods, however, can. Uncertainty estimation in volumetrics for supporting. Risk infers that there is some material implication in the outcome.
Risk and uncertainty can be related at times, however sometimes uncertainty carries no material risk. Uncertainty analysis of thermocouple measurements 10 1 executive summary an uncertainty analysis was performed on several data acquisition systems dass that use type k chromelalumel thermocouples tcs. Rf stoiip 1100 1600 2100 2600 3100 3600 ur mmstb figure 6. World academy of science, engineering and technology. Chapter 6 petroleum economics uncertainty and risk. Guidelines for the evaluation of petroleum reserves and resources. Pdf coupling spatial and frequency uncertainty analyses in. Constraining uncertainty in static reservoir modeling. Decline curve analysis for estimating eurs and ooips. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. Coupling spatial and frequency uncertainty analyses in reservoir modeling. Petrel uncertainty analysis and optimization fundamental subsurface uncertainties assessment is an essential phase in any field development strategy. Since all geostatistical methods used in estimation of reservoir parameters are inaccurate, modeling of estimation error in form of uncertainty analysis is very important.
Other example from the western desert presented the effect of geological uncertainty on stoiip calculations of the cretaceous kharita reservoir. Conceptual basis for uncertainty analysis annex 1 a1. Uncertainty study on inplace volumes in statoil ninth. Mcmichael over the past 60 years, numerous technical organizations, regulatory bodies, and. Stoiip were estimated at 12, 25 and 95 million tons for 1p, 2p and 3p categorizes respectively. Our main concern is the impact uncertainty has on petroleum investment. Quantifying uncertainty differs for single measurements versus sample means. Uncertainty calculator standard operating procedure required by estimating type i and type ii errors. From the well data and background knowledge, the probability density functions pdfs. The stoiipuncertainty for a given segment in a given zone is modeled as where grv, ewell.
Evaluating uncertainty in the volumes of fluids in place in an. An uncertainty analysis gives us the support we need for decisions about milestones in the plan and buffers to protect against the impact of variability. Examples are presented in which uncertainty analysis was utilized or is needed to gain further knowledge of a particular measurement process and to characterize final results. Neumann1, bjorn kare hegstad2, elisabeth bratli3, inger kloster osmundsen4. Pdf uncertainty analysis encompasses the quantification and. A methodology is presented for uncertainty estimation in volumetrics. Tornado diagram illustrating the uncertainties affecting the ur. This course learning contents are design to provide the reservoir engineers with the concepts and necessary application skills for uncertainty assessment quantification and optimizations using. Stoiip validation for a heterogeneous multilayered. The uncertainties included in the uncertainty analysis of inplace volumes are. Guidelines for the evaluation of petroleum reserves and.
Guidelines on uncertainty analysis in exposure assessment. To better understand reserves estimation, a few important terms require definition. Uncertainty analysis now we will use what we learned in chap. As production continues, the accuracy and reliability of the estimates obtained from rta, material balance, and decline analysis increases. Uncertainty study on inplace volumes in statoil kjersti b. The significance of the standard deviation is this. Principles and applications of measurement uncertainty. Integrating all the techniques provides more reliable answers than relying solely on any. Pdf coupling spatial and frequency uncertainty analyses. Weyant energy modeling forum, stanford university terman engineering building, room 406 stanford, ca 94305 emf working paper 14. Facies interpretation and modelling an integrated workflow. Sensitivity analysis of input parameters shows a decreasing order effect on reserve estimate from thickness, area, porosity, water saturation and formation volume factor for first and second simulation analysis respectively keywords. Quantifying uncertainty, oil reserves estimate, stochastic, techniques.
Index termsuncertainty in scheduling, stochastic time. Ninth international geostatistics congress, oslo, norway june 11 15, 2012 uncertainty study on inplace volumes in statoil kjersti b. Monthly production volumes provide the data for material balance and decline analysis techniques. Remember that errors can be divided into two categories, bias and precision errors. These measurements are made in typical experiments performed. This array of variability presents a significant challenge in assessing the viability of recovering hydrocarbon. New approaches to geological uncertainties in stoiip. Uncertainty can be modeled, but there is no objective measure of uncertainty. Mehdi behnamrad, behnam jan ahmad, geostatic modeler. Petrel uncertainty analysis and optimization fundamental.
Estimating resource and reserves crosses the disciplines between geoscientists and petroleum engineers. Random uncertainty for a sample mean is estimated from the standard deviation, scaled by the tdistribution and the sample size. A framework for input uncertainty analysis russell r. Uncertainty analysis of thermocouple measurements used in. In the following gives an example by use of microsoft project and a special data program for planning under uncertainty. Stoiip validation for a heterogeneous multilayered reservoir of a. 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. It is common practice within oil companies to use expectation curves to express ranges of uncertainty.
Decline curve analysis three basic decline curve equations. This extremely wide range of reserves reflects high geological uncertainty. Systematic or bias b uncertainty is the same in both cases, but random or precision p uncertainty is reduced by increased sample size. Approaches for performing uncertainty analysis in largescale. How to apply the monte carlo simulation principles to a game of dice using microsoft excel. The uncertainty associated with each parameter may be expressed in terms of a probability density function pdf, and these may be combined to create a pdf for stoiip. Abstract this presentation focuses on a field case where the statoil standard workflow for estimating the uncertainty in inplace volumes is used.
Original oil in place ooip original oil in place and original gas in place ogip original gas in place refer to the total volume of hydrocarbon stored in a reservoir prior to production. While the geoscientist may well have primary responsibility, the engineer must carry the resource and reserve models forward for planning and economics. After the stages described above, 100 realizations of complete model were generated by varying seed number alone. Mcmichael over the past 60 years, numerous technical organizations, regulatory bodies, and financial. In this first iteration parameters were ranked by stoiip and p90, p50 and p10 cases picked as low, base. Across the breadth of hydrocarbon exploitation there is uncertainty from acquisition, analysis, application, technology, and economics, all the way to timing and resources. Stoiip validation for a heterogeneous multilayered reservoir. Approaches for performing uncertainty analysis in largescale energyeconomic policy models antje kann and john p.
Calculating oil in place by the volumetric method oil in place by the volumetric method is given by. During the asset life cycle more data is obtained in order to do technical analysis to provide. The highest ranked contributors to uncertainty in stock tank oil initially in place stoiip were oil water. A geological uncertainty study was initiated to identify and quantify the input parameters of. The relationship between pdfs and expectation curves is a simple one. Guidelines for the evaluation of petroleum reserves and resources 1 chapter 1 summary introduction claude l. Uncertainty assessment in 3d reservoir modeling an integrated approach uncertainty is not an inherent feature of our reservoirs. In this study, drive index 8 helped defining the most effective parameters to constraint uncertainty in production and pressure.
Example of judy creek reef complex in swan hills, alberta, canada article pdf available in aapg memoir december 2011. Project planning, uncertainty analysis and critical chain. We will study uncertainty analysis for the following measurement situations. Figure 61 tornado diagram illustrating the uncertainties. In statoil there is a requirement to undertake a thorough uncertainty analysis before making an. Certain biological tests, spot tests, and immunoassay tests are included in this category.
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