It is a semianalytical approach in that type curves are generated from analytical solutions of transient infinite radial systems at constant flowing pressure, while the boundarydominated flow period is defined using hyperbolic decline typecurves, originally developed by arps. This technique, which is similar to the approach used in pressure testing, involves loglog plots of qq i or q dd versus a i t or t dd for different values of n see figure 5. Advanced production decline analysis and application by. Reliable information about the coronavirus covid19 is available from the world health organization current situation, international travel. Analysis of production decline curves ebook, 2008 worldcat. However, a great number of studies on production decline analysis are still based on this empirical method. Oclcs webjunction has pulled together information and resources to assist library staff as they consider how to handle coronavirus. Download citation decline curve analysis this chapter covers different decline curve models and the use of decline curve models for reservoir performance. Production declinecurve analyses are the most widely used tool in the industry for oil and gas reservoir production analyses. The empirical arps decline equation represents the relationship between. Production decline curve analyses are the most widely used tool in the industry for oil and gas reservoir production analyses. Traditional decline generates a forecast of future production rates based on the equations defined by arps. However, the application of pdca in shale gas reservoirs is relatively new.
A decline curve analysis model based on fluid flow. Fetkovichcourseoutline basic concepts in decline curve. However, most curve analysis is done by computer today, promoting a blackbox approach to engineering and leaving engineers with little background in the fundamentals of decline analysis. As a result, the fetkovich arps decline analysis method is fit for the condition when the well is producing with constant bhfp, and the type curve could not be used until it reaches the period of boundarydominated flow. Estimate what the wells potential rate will be when the static pressure dropped to 1500 psig. Using vogels method, draw the ipr curve, and estimate the wells potential. Fetkovich plots are even used to describe the behaviour of unconventional well production data e. Decline analysis can be used to predict different oil wells production nature decline rule. The most popular decline curve is that which represent the decline in the oil or gas. A decline curve analysis model based on fluid flow mechanisms.
A method for estimating reserves and predicting production in oil reservoirs and oil fields. Advanced production decline analysis and application starts from the basic concept of advanced production decline analysis, and thoroughly discusses several. The arps decline curve analysis approach4 was proposed nearly sixty years ago. Computerassisted approach, elsevier science and technology books, 2007, pages. He suggested that e xperimental production rate data could be overlaid on a graph and matched to a series of type curves. Spe spe 14237 case study of a lowpermeability volatile oil field using individualwell advanced decline curve analysis by m. For exponential decline it is a constant with time. A practical systematic introduction to each method helps the reservoir. Fetkovich typecurve analysis theory fekete associates.
Feb 19, 2015 however, most curve analysis is done by computer today, promoting a blackbox approach to engineering and leaving engineers with little background in the fundamentals of decline analysis. Before the availability of computers, decline curve analysis was performed by hand on semilog. An ideal decline curve for shale wells would be able to forecast linear flow followed by boundarydominated flow. This popular course explores reservoir engineering in relation to decline curves and the types of decline curves used and how they are applied throughout the industry. J decline curve analysis for variable pressure dropvariable flow rate systems spe paper 215 presented at the spe gas technology symposium january 2324. Production forecasting decline curve analysis petrowiki. Spe 167253 decline curve analysis for unconventional.
Read advanced production decline analysis and application online. The production rate is then extrapolated into the future with the assistance of the curves. Aug 04, 2015 the arps decline curve analysis approach was proposed nearly60 years ago. Numerous and frequentlyupdated resource results are available from this search. Fetkovich showed that the value of b was an indication for efficiency of recovery, where zero was the lowest efficiency with small compressibility and 0. An advanced approach for decline curve analysis, which is applicable for changes in pressure or drainage, has been presented by fetkovich, 14. If you have a fairly fast connection, you may wish to download the entire package. Raghavan and ohaeri 19, and sageev zo also examined the rate dedine behavior of naturally fractured reservoirs. Pdf verification of decline curve analysis models for.
Fetkovich dca decline curve analysis course whitson academy. Probabilistic decline curve analysis pdca methods have been developed to quantify uncertainty in production forecasts and reserves estimates. In recent years, production declinecurve analysis has become the most widely used tool in the industry for oil and gas reservoir production analysis. N2 to understand the reservoir flow behavior and estimate its parameters e. The decline curve shows how oil and gas production rates decrease over time. In gomsmart, decline curve analysis is available from the feature info page under completions only. Decline curve analysis is an exercise in seeing, understanding and predicting the reservoir and operational dynamics. Read unlimited books and audiobooks on the web, ipad, iphone and android. Limited work has been done on the performance of pdca methods when the available production data are limited.
The limitation of this technique is that the transient typecurves are restricted to radial flow systems, and the method does not directly calculate originalhydrocarbonsinplace as is the case in modern methods. Finally, the analytical model was compared with conventional. For a more detailed explanation see analysis of decline curves. Fetkovich, mj 1980 decline curve analysis using type curves. Decline curve analysis is an empirical procedure that predicts the decline in production rates of gas and oil wells. Analysis of production decline curves digital edition. Prediction of reservoir performance in multiwell systems. The effective decline factor d is a stepwise function that is in better agreement with data recording practices.
Pdf prediction of reservoir performance in multiwell. These work indicate that the double porosity model predicts an initial high flowrate followed by p sudden rate decline and a period of constant 1. Workflow for applying simple decline models to forecast. Advanced production decline analysis and application. Depletion has a fundamental role in the extraction of finite resources and is one of the driving mechanisms for oil flows within a reservoir. Decline curve analysis for estimating eurs and ooips. Reservoir evaluation decline curve analysis esanda. Fetkovich 2 developed type curve, marhaendrajana and blasingame 5 extended type curve method to a multiwell system, and li and horn 3 verified decline curve analysis dca method. Because his method was rapid and easily applied, it was used extensively by ramsay in his evaluation of some 200 wells to determine the distribution of the decline curve exponent b.
This technique, which is similar to the approach used in pressure testing, involves loglog plots of qq i or q dd versus. Case study of a lowpermeability volatile oil field using. Decline curve analysis is a means of predicting future oil well or gas well production based on past production history. Types of decline analysis in production forecasting. Fetkovich 1968 improved on earlier work by arps in predicting the declining production rate of oil and gas wells.
The fetkovich typecurve analysis spe 004629, 1980 was the first analysis method to use analytical typecurve matching for production data. Basic concepts in decline curve analysis by mike fetkovich table of contents tape 1 click here to watch the entire fetkovich course from beginning to end of tape 1. Decline curve analysis predicts the decline in production rates of gas and oil wells as they age. In recent years, production decline curve analysis has become the most widely used tool in the industry for oil and gas reservoir production analysis. The proposed discussion and workshop consists of 6 major subjects with attendant work problems. J decline curve analysis using type curves jpt june 1980 1065. Depletion rate also can be connected to decline curves. Sep 15, 2011 decline curve analyses are usually based on empirical arps equations.
Decline curve analysis is the most common method used in reservoir engineering calculations to predict future field production rates from historical production data. A new direction for decline curve analysis was given by slider 2 with his development of an overlay method to analyze ratetime data. These variables must all give consistent and reasonable numbers when compared with each other. The applicable decline for the purpose of reservoir estimates is usually based on the historical trend that is seen on the well or reservoir performance. Verification of decline curve analysis models for production. Decline curve analysis three basic decline curve equations all of the equations give you the ability to predict cumulative production or production rate at some point in time. Decline curve analyses are usually based on empirical arps equations. The empirical arps decline equation isused to represent the relationship. Decline curve analysis using fetkovichstyle type curves.
Furthermore, we also introduce several cases with applications using the above method. System identification based proxy model of a reservoir. Fetkovichs decline curve dimensionless variables are defined as below12. Fetkovich transient and arps decline curve analysis techniques, methods to amend a nonconverging production curve to force it to the economic limit, reinitializing decline curves, material balance time, and real time relationships will also be covered throughout the duration of this course. Basic concepts in decline curve analysis by mike fetkovich table of contents tape 1 click here to watch the. Data points lying outside the type curve represent transient flow. Prediction of reservoir performance applying decline curve analysis. Fetkovich decline curve analysis excel calculations. Advanced production decline analysis and application starts from the basic concept of advanced production decline analysis, and thoroughly discusses several decline methods, such as arps, fetkovich, blasingame, agarwalgardner, npi, transient, long linear flow, and fmb. Decline curve analysis has been called the most commonly used and misused technique for forecasting future production and remaining reserves. Decline curve analysis is not a curve fitting exercise, and it should not be limited to a single ratetime graph of each well in isolation, much less just any ratetime graph created by the sloppy defaults of most graphing programs. System identification based proxy model of a reservoir under. This book will serve as an authoritative reference on modern production declinecurve analyses, including details of some recent advances in the technology. Prediction of reservoir performance applying decline curve.
Fetkovich, spe distinguished member and developer of the widely used fetkovich type curve analysis for oil and gas well production. However, formatting rules can vary widely between applications and fields of interest or study. Furthermore, we made computer programming in matlabm language to calculate the natural decline rate with any time, which made it much easier and practical to predict the future decline rate. Declines curve analysis is a common way to forecast future production rates and to determine the expected ultimate recovery of resources. Effectivewell method for matching and predicting oil. This book will serve as an authoritative reference on modern production decline curve analyses, including details of some recent advances in the technology. Types of decline analysis in production forecasting petrowiki.
It is a semianalytical approach in that type curves are generated from analytical solutions of transient infinite radial systems at constant flowing pressure, while the boundarydominated flow period is defined using. This course will give the learner a better understanding of how fundamental reservoir properties and drive mechanisms affect the shape of the production decline curve and how to avoid many of the mistakes commonly found in decline curve forecasts. Jan 01, 2017 an improved dca which considers reservoir parameters as part of the decline analysis was developed by fetkovich 4 and is referred to as fetkovich s type curve analysis. Many published papers have tried to interpret the arps declineequation theoretically 67. Decline curve analysis dca is a graphical procedure used for analyzing declining production rates and forecasting future performance of oil and gas wells.
Fetkovich used analytical flow equations to generate typecurves for transient flow, which he combined with the empirical decline curve equations originally documented by j. Production decline analysis is a traditional means of identifying well production problems and predicting well performance and life based on real production data. An advanced approach for declinecurve analysis, which is applicable for changes in pressure or drainage, has been presented by fetkovich, 14. Decline curve analysis is the most currently method used available and sufficient 1. T1 decline curve analysis for tight gas and gas condensate reservoirs. If your connection is slower, you will want to download the files separately. Nominal decline is a continuous function and it is the decline factor that is used in the various mathematical equations relating to decline curve analysis. To interpret rate transient analysis for the determination of. Jun 19, 2015 for the love of physics walter lewin may 16, 2011 duration. Rate decline analysis for horizontal wells with multiple. Prediction of reservoir performance in multiwell systems using modified hyperbolic model. This excel spreadsheet plots fetkovich decline curves for gas wells. Decline analysis curve an overview sciencedirect topics. Black dots represent the outliers, whereas red dots are the oil rates included in the analysis.
Depletion and decline curve analysis in crude oil production. In addition, this chapter also introduces several concepts related to the apda. Decline curve analysis for tight gas and gas condensate. If not, the matching point of r ed will be multiple. It involves matching production data history to an empirical equation and simply extrapolating the production trends. Many published papers have tried to interpret the arps 4 decline equation theoretically. Advanced production decline analysis and application in. Advanced production decline analysis and application ebook. Advanced production decline analysis and application 1st edition. However a great number of studies on production decline analysis are still based on this empirical method.
Fetkovich dca decline curve analysis course youtube. Brons 1963 and fetkovitch 1983 applied constant pressure solution to diffusivity equation and demonstrated that. Production decline curve analysis is a traditional means of identifying well production problems and predicting well performance and life based on measured oil well production. Oil and gas production rates decline as a function of time. It uses empirical decline models that have little fundamental justifications. Fetkovich recognized that decline curve analysis was only applicable during the depletion period ie.
This remains an important tool for the reservoir engineer, so that the practice of decline curve analysis has been. Ratetime decline curve analysis is a major technique which is mostly. Multiwell decline curve analysis shows the validity of the variables s skin, k, ooip, ultimate fractional recovery and gor versus fractional recovery evaluated from each wells type curve match point. Decline curve analysis is a long established tool for developing future outlooks for oil production from an individual well or an entire oilfield. In addition to reserves, calculated from the depletion stem bvalue match, this. In recent years, production declinecurve analysis has become the most widely used tool in the. Decline curve analysis three basic decline curve equations all of the equations give you the ability to predict cumulative production or. View notes fetkovichcourseoutline from petroleum 2 at petronas technology university. Decline curve analysis for unconventional spe 167253 3 for the case of unconventional reservoirs e. In recent years, production declinecurve analysis has become the most widely. Study on the decline analysis of oil well stimulation rule. Advanced production decline analysis and application 1st.