Decline curve analysis dca is a graphical procedure used for analyzing declining production rates and forecasting future performance of oil and gas wells. This book will serve as an authoritative reference on modern production declinecurve analyses, including details of some recent advances in the technology. Exponential decline appears to be a rare occurrence in nature, even though it is the most commonly used decline technique fetkovich theorydeveloped because traditional decline curve analysis is only applicable when well is in boundary dominated flow fetkovich used analytical flow equations to generate typecurves for transient flow, and. Gas reservoir declinecurve analysis using type curves with. 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. Fetkovichs decline curve dimensionless variables are defined as below12. Over the past few years, several empirical models have emerged to address the second limitation, but they. Reserve estimation using decline curve analysis for boundary. The most popular decline curve is that which represent the decline in the oil or gas. The constantpressureinfinite and finite reservcir solutions are placed on a common dimensionless curve with all the standard empirical expmential, hyperbolic, arid harmoni declinecurve. The constantpressureinfinite and finite reservcir solutions are placed on a common dimensionless curve with all the standard empirical expmential, hyperbolic, arid harmoni declinecurve equations. Fetkovich 1968 improved on earlier work by arps in predicting.
On a larger perspective, it aids as a means of identifying well production problems. Historymatching and forecasting of three unconventional oil. Oil and gas production rates decline as a function of time. Data points lying outside the type curve represent transient flow. Pdf decline curve analysis using type curves evaluation. The use of the fetkovichmccray type curve format i.
The analytic dimensionless terms for pressure, production rate, decline rate, and decline time were derived for saturated steam using the real gas potential and. Pdf decline curve analysis using type curves evaluation of. Discussion and study guide spe 4629 decline curve analysis using type curves m. Fetkovich dca decline curve analysis course youtube. The analytic dimensionless terms for pressure, production rate, decline rate, and decline time were derived. Decline type curve analysis fetkovich mccray format. These variables must all give consistent and reasonable numbers when compared with each other. Prediction of reservoir performance applying decline curve analysis. Reserve estimation using decline curve analysis for.
Types of decline analysis in production forecasting. This, in fact, is a graphical method for visual matching or comparison of observational data using preplotted curves on a loglog diagram 8. Fetkovich documented that decline curve analysis that only applicable through the reduction period, when production reaches in boundarydominated flow. Production decline data from different types of waterdrive reservoirs were analyzed as examples of using the new decline analysis model. Comparison of empirical decline curve analysis for shale wells a thesis. Decline curve analysis using type curves evaluation of well performance behavior in a multiwell reservoir system. Jun 19, 2015 for the love of physics walter lewin may 16, 2011 duration.
Pdf decline curve analysis using type curves semantic scholar. Exponential decline appears to be a rare occurrence in nature, even though it is the most commonly used decline technique fetkovich theorydeveloped because traditional decline curve analysis is only applicable when well is in boundary dominated flowfetkovich used analytical flow equations to generate typecurves for transient flow, and. Production decline analysis is a traditional means of identifying well production problems and predicting well performance and life based on real production data. Arps type curves could only be used to analyze the data in the period of boundarydominated flow. Using vogels method, draw the ipr curve, and estimate the wells potential. Historymatching and forecasting of three unconventional. It uses empirical decline models that have little fundamental justifications. Fetkovich recognized that decline curve analysis was only applicable during the depletion period ie. A decline curve analysis model based on fluid flow mechanisms. In the early 1980s, fetkovich introduced an analysis of decline curve using type curves. Production forecasting decline curve analysis petrowiki. Fetkovich 2 developed type curve, marhaendrajana and blasingame 5 extended type curve method to a multiwell system, and li and horn 3 verified. Geological survey scientific investigations report 20175062, p.
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. Spe 84287 decline curve analysis using type curves. Permeabilitythickness determination from transient. Fetkovich 1971 developed a method of describing the approximate water influx behavior of a finite aquifer for radial and linear geometries. Analysing gas well production data using a simplified decline curve analysis method. This paper presents rigorous methods to analyze and interpret exponential,hyperbolic. The production data analysis methods started long ago when a decline trend was used as a tool for economic evaluation. Basic concepts in decline curve analysis fetkovich tapes table. This faper shows that the declinecurve analysis approah does have a solid fundamental basis. Production decline curve analyses are the most widely used tool in the industry for oil and gas reservoir production analyses. Production declinecurve analysis is accepted for prediction of future performance of oil and gas wells and fields. Pdf verification of decline curve analysis models for. Arps three types of decline and their formulas on a semilog plot after arps 1945. Fetkovich established the typecurves that extended the arps type curves into the transient flow region 3,4.
Aug 22, 2017 most decline curve methods have two main limitations. A decline curve analysis model based on fluid flow. Equation, decline curve and type curve technique, of which decline curve analysis numbers among the earliest methods and yet the conventional tool most practically applied. The left part when t dd decline rate curve shifts downwards with the increased r ed, and the right part when t dd 0. Estimate what the wells potential rate will be when the static pressure dropped to 1500 psig. Assessment of reservoir performance of a well in south. Discussion and study guide spe 4629 decline curve analysis using. Truncating a hyperbolic decline with an exponential decline solves some of the problems associated with decline curve analysis, but it is not an ideal solution. Spe 84287 decline curve analysis using type curves fractured.
Case study of a lowpermeability volatile oil field using. Decline curve analysis is the most currently method used available and sufficient 1. 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. Fetkovich 1968 improved on earlier work by arps in predicting the declining production rate of oil and gas wells. Application of decline curve analysis to estimate recovery. Advanced production decline analysis and application. The exponential decline rate used is arbitrary, and the value picked greatly affects the results of the forecast clark, 2011. Agarwal and gardner have compiled and presented decline type curves for analysing. 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. Matching and extrapolating these curves is equivalent to using the harmonic and hyperbolic declines with the usual semilog decline curves. Pdf analysing gas well production data using a simplified. Pdf decline curve analysis using type curves semantic.
Decline curve analysis has been called the most commonly used and misused technique for forecasting future production and remaining reserves. Brons 1963 and fetkovitch 1983 applied constant pressure solution to diffusivity equation and demonstrated that. Production data analysis future practices for analysis. Rate decline analysis for horizontal wells with multiple. Jahediesfanjani, hossein, 2017, application of decline curve analysis to estimate recovery factors for carbon dioxide enhanced oil recovery, chap. The b0 case is for exponential decline of a liquid reservoir. Decline curve analysis three basic decline curve equations all of the equations give you the ability to predict cumulative production or. If your connection is slower, you will want to download the files separately. One type of clinecurve analysis involves the hyperbolicdeclinecurve equation. Spe 4629 decline curve analysis using type curves semantic. Pdf analyzing well production data using combinedtype. The fetkovich production decline curve analysis method was extended for application to vapordominated geothermal reservoirs for the purpose of estimating the permeabilitythickness product kh from the transient production response. An approach to modeling production decline in unconventional. These rate integral and rate integral derivative typecurves aid in obtaining a more unique match.
Fetkovich introduced the idea of loglog type curve analysis to. Pdf a decline curve analysis was used for evaluating the well performance. To understand the effects of main parameters on rate transient behaviors of a hwms, we develop the blasingame compound type curves to perform the sensitivity analysis through the rda model proposed in this paper i. Most of the existing decline curve analysis techniques are based on the empirical arps equations4. 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. Types of decline analysis in production forecasting petrowiki. For boundarydominated flow, fetkovich showed the arps family of curves with b as a parameter.
For the love of physics walter lewin may 16, 2011 duration. Decline curve analysis is an empirical procedure that predicts the decline in production rates of gas and oil wells. This study compares four recently developed decline curve methods and the traditional arps or fetkovich approach. Decline type curve analysis fetkovichmccray format. Over the past few years, several empirical models have emerged to. Fetkovich used the curves with values of b between 0 and 1 hyperbolic and harmonic decline for matching solutiongasdrive depletion and gas reservoir depletion. Black dots represent the outliers, whereas red dots are the oil rates included in the analysis. This book will serve as an authoritative reference on modern production decline curve analyses, including details of some recent advances in the technology. If you have a fairly fast connection, you may wish to download the entire package. Fetkovich 2 developed type curve, marhaendrajana and. Fetkovich published 2002 ratetime decline curve extrapolation is one of the oldest and most often used tools of the petroleum engineer. Gas reservoir declinecurve analysis using type curves. Mathematics the arps decline curve analysis approach4 was proposed nearly sixty years ago. 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.
Modified fetkovich type curve which includes transient linear b 2 and. Its output the estimation of remaining reserves is completely dependent. Decline curve analysis for estimating eurs and ooips. In many cases, the results of this model closely match those determined using the van everdingenhurst approach. Blasingames improvements on the fetkovich style of production decline analysis are further enhanced by the introduction of two additional typecurves which are plotted concurrently with the normalized rate typecurve. Production declinecurve analyses are the most widely used tool in the industry for oil and gas reservoir production analyses. A practical systematic introduction to each method helps the reservoir. A normalized time has been developed that linearizes the rate decline vs. 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. Analysis methods traditional background for traditional analysis decline curve analysis is a graphical procedure used for analyzing declining production rates and forecasting future performance of oil and gas wells. We would like to clarify that our study and the discussions in this article are limited to twophase fluid flow. 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.
Fetkovich decline curve analysis excel calculations. A new direction for decline curve analysis was given by slider 2 with his development of an overlay method to analyze ratetime data. Arps in 1945 presented the classical decline curve analysis dca technique which is based on pure empirical. Spe spe 14237 case study of a lowpermeability volatile oil field using individualwell advanced decline curve analysis by m. A loglog plot with combined radial and bdf declines for various reservoir boundaries.
The socalled blasingame plot palacio and blasingame 1993 and doublet, et al 1994 is a replot of the traditional fetkovich plot fetkovich 1980, with provisions for a variable rate and pressure histories as opposed to the. Fetkovich dca decline curve analysis course whitson academy. Workflow for applying simple decline models to forecast. Most decline curve methods have two main limitations. 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 excel spreadsheet plots fetkovich decline curves for gas wells. A curve fit of past production performance is done using certain standard curves.