This course begins with a brief description of the theory of decline curve analysis and its background. Formation factor and remaining oil saturation are included in this model, which reveals nonlinear relationships between natural decline rates and the production time. Petroleum engineers, landmen, royalty owners, prospectors, and everyone in between can easily use quick decline to get a leg up on the competition. Please direct your comments and questions to the author, dr. Decline curve analysis regression analysis applied. All functions are organized by categories for easy navigation and have a informative description.
Decline curve analysis dca is a technology that can be used to extrapolate observed early time production to predict future rate performance and the expected ultimate recoverable reserve eur volume that the well will produce during its life typically 20 to 30 years. Thus, a major advantage of this decline trend analysis is inclusion of all production and operating conditions that would influence the performance of the well. In the case of oil recovery improvements, such as infill, fracturing and fluid injections, the decline curve analysis is implemented to evaluate reservoir performance by comparing production outputs before and after these methods application. This allows type curve matching of the exponential decline curve for a reservoir with any shape. Decline curve analysis is a means of predicting future oil well or gas well production based on past production history.
Advanced production decline analysis and application, sun. There are several models related to the decline curve equation. A fractional decline curve analysis model for shale gas reservoirs. Advanced production decline analysis and application. This book will serve as an authoritative reference on modern production declinecurve analyses, including details of some recent advances in the technology. This explains decline analysis and shows a working example. Prediction of reservoir performance in multiwell systems using. Oil and gas conventional decline analysis roger sakatch. Decline curve analysis oil reserves petroleum reservoir. Apr 12, 2019 after this level has been reached transient flow period, there is a decline in production usually caused by loss of reservoir pressure or changing volumes of produced fluid. The hyperbolic curve requires estimation of both di and the exponent b. Decline analysis can be used to predict different oil wells production nature decline rule. An advanced approach for decline curve analysis, which is applicable for changes in pressure or drainage, has been presented by fetkovich 267, 268.
Petroleum office is an addin that integrates a ribbon tab into the excel window, giving you easy access to the included functions and tools. Decline curve analysis using two empirical models, the hyperbolic and the stretched exponential function, was used to derive typical tight oil production curves. This book covers the production characteristics and associated interpretation analyses of petroleum reservoirs in a. 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.
A normalized time has been developed that linearizes the rate decline vs. Analysis of production decline curves spe book store. Decline curve analysis models are frequently used but still have many limitations. Decline curve analysis dca is used to predict the future production of oil. Then, a decline analysis model is derived based on reservoir characteristic parameters and used to analyze natural decline rates for the xiaermen oilfield developed by waterflooding. The rate of production decline is depicted by a decline curve. The decline curve shows how oil and gas production rates decrease over time.
Since the beginning of this century the shale oil production has increased from practically zero to currently supply almost half of the u. Decline curve analyses are usually based on empirical arps. Production decline curve analyses are the most widely used tool in the industry for oil and gas reservoir production analyses. Decline curve analysis, introduced in the 1940s, is one of the most popular methods to date for evaluating the future production potential of oil and gas wells 1,2. Crains petrophysical handbook reserves from decline curve. Jan, 2014 this connects decline curve models with the depletiondriven production declines caused by the exhaustion of recoverable resources. In recent years, production decline curve analysis has become the most widely used tool in the industry for oil and gas reservoir production analysis. Decline analysis is applicable, as a technique, when volumetric sweep is changing slowly and when relative permeability is controlling oil rates. Decline curves are generally easy to use, but type curves usually provide better forecasts for complex reservoirs. Decline curve analysis dca is a graphical procedure used for analyzing declining production rates and forecasting future performance of oil and gas wells. Prediction of reservoir performance applying decline curve. Decline curves are generated from decline curve analysis dca software.
Depletion has a fundamental role in the extraction of finite resources and is one of the driving mechanisms for oil flows within a reservoir. The agarwalgardner type curve analysis spe 057916, 1998 is a practical tool that can easily estimate the gas or oil inplace, as well as reservoir permeability, skin effect, and fracture halflength for hydraulically fractured wells. The fullsize fetkovich typecurves can be ordered from the book order department of spe. A decline curve analysis model based on fluid flow mechanisms. The cumulative oil production after the production decline upon decline time t can also be evaluated based on the total reservoir compressibility. Quick decline is the ultimate production oil and gas decline analysis and economic evaluation tool for everyone. Decline curve analysis and its role in oil production forecast. The case of eagle ford linnea lund production of oil and gas from shale is often described as a revolution to energy production in north america. Decline curve analysis is probably the most widely used but at the same time mostly misunderstood methodology in petroleum engineering. Depletion rate also can be connected to decline curves. Decline curve analysis of oil and gas wells has evolved over time as we have learned how a reservoir behaves. Estimated ultimate recovery an overview sciencedirect.
New chapters on decline and type curve analysis as well as reservoir simulation updated material including the liquid volatility parameter, commonly designated rv provides a guide to predicting oil reservoir performance through the analysis of oil recovery mechanisms and performance calculation. Conventional decline curve analysis should be used only when mechanical conditions and reservoir drainage remain constant and the well is producing at capacity 197. Thus, they all assume constant operating conditions over the flowing life of a well. Decline curve analysis when the average reservoir pressure decreases with time due to oil and gas production, this in turn causes the well and field production rates to decrease yielding a rate time relation similar to that in the following figure.
What is a decline curve the decline curve is a method for estimating reserves and predicting the rate of oil or gas production. Traditional data analysis 114 reservoir simulation models 116. Sep 10, 2016 wells have a type curve that profiles expected production over their lifetime. The production forecasting guidelines will address the following types of decline analysis. Gas reservoir declinecurve analysis using type curves with. A method for estimating reserves and predicting production in oil reservoirs and oil fields. Forecasting oil and gas production for unconventional wells. Methods of decline curve analysis for shale gas reservoirs.
The existing decline curve analysis dca equations, some with valid theoretical justifications, cannot directly react to changes in operating conditions. Apr 27, 2006 new chapters on decline and type curve analysis as well as reservoir simulation updated material including the liquid volatility parameter, commonly designated rv provides a guide to predicting oil reservoir performance through the analysis of oil recovery mechanisms and performance calculation. The purpose of a decline analysis is to generate a forecast of future production rates and to determine the expected ultimate recoverable eur reserves. Decline curve analysis using arps empirical algorithms. In todays post, i will go over automating decline curve analysis for oil and gas wells, using both an exponential and a hyperbolic line of best fit. Types of decline analysis in production forecasting. For the oil gas well with edgebottom aquifer, the decline analysis curve can be separated into four stages, which are listed as follows with the corresponding characteristics, as shown in figure 12. This paper shows that the decline curve analysis approach does have a solid fundamental basis. Using an unified approach, the text includes the full range of reservoir fluids. Exploratory data analysis 111 reservoir characterization cycle 114 traditional data analysis 114.
The data for reservoir a located southeast, nigeria. These methods are simple and economic to apply and can provide valuable data on the quality of the reservoir. In cases for a decline in rate of production, the data are extrapolated into the future. The addition of practical field case studies make reservoir engineering a valuable resource for reservoir engineers and other professionals in helping them implement a comprehensive plan to produce oil and gas based on reservoir modeling and economic analysis, execute a development plan, conduct reservoir surveillance on a continuous basis. Oil depletion is the decline in oil production of a well, oil field, or geographic area. Oil and gas production rates decline as a function of time. Both type curve fitting and type curve matching techniques will be explained and demonstrated. Natural decline trend is dictated by the reservoir drive mechanism, rock and fluid properties, well completion, and production practices. Advanced production decline analysis and application kindle edition by sun, hedong. Decline curve analysis dca is a common graphical procedure used for understanding declining production rates and forecasting performance. Each function from addin can be selected from insert function dialog as well as from ribbon group. Traditional decline generates a forecast of future production rates based on the equations defined by arps.
Use features like bookmarks, note taking and highlighting while reading advanced production decline analysis and application. The y axis is a semi log scale, indicating the rate of oil depletion green line, and gas depletion red line. Advanced production decline analysis and application 1st. Advanced production decline analysis and application 1st edition. It covers rock and fluid properties, reservoir energies, surface separation, laboratory pvt methods, material balance, fluid flow, well deliverability, water influx, reservoir performance, and decline curve analysis. Petroleum engineering calculations in microsoft excel. How to automate decline curve analysis dca in python using scipys optimize. This reservoir engineering textbook is a contemporary analysis of primary recovery.
Types of decline analysis in production forecasting petrowiki. Decline curve analysis is a reservoir engineering empirical technique that extrapolates the trends in the production data from oil and gas wells. Performing accurate analysis and interpretation of reservoir behavior is fundamental to. Using decline curves to forecast waterflooded reservoirs. The hubbert peak theory makes predictions of production rates based on prior discovery rates and anticipated production rates. Prediction of reservoir performance applying decline curve analysis. Oil and gas decline curves rock river minerals, lp. The conventional analysis of production decline curves for oil or gas production consists of plotting the log of flow rate versus time on semilog paper. Decline curve analysis is the most common method used in reservoir. Initial production ip rates were compiled, and together with derived production decline curves estimated ultimate recovery eur of wells was calculated based on different.
Over time, well production rates typically decrease from a loss of reservoir pressure or changing volumes of the produced fluids. New to this edition is an additional chapter devoted to enhanced oil recovery techniques, including wag. Although decline curve interpretations have changed, the fundamentals are the same. Decline curve analysis is a long established tool for developing future outlooks for oil production from an individual well or an entire oilfield. Hubbert curves predict that the production curves of nonrenewing resources approximate a bell curve. The more common type curve fitting methods are demonstrated using. Two main analysis methods are decline curve analysis and type curve analysis. They utilize past production history of a petroleum reservoir to create a well production profile. Decline curve analysis is a means of predicting future oil well or gas well production based on.
Decline analysis curve an overview sciencedirect topics. Critical new advances in areas such as well performance, waterflooding, and an analysis of decline and type curves are also addressed, along with more information on the growing extraction from unconventional reservoirs. Quick decline production oil and gas decline analysis and. Advanced production decline analysis and application starts from the basic concept of advanced production decline analysis, and discusses several decline. Typically, decline analysis is conducted on a plot of. Approaches of decline curve analysis used for naturallyfractured reservoirs developed by water flooding have been few. Comparative analysis of forecast of rate of production of oil from a reservoir using decline curve analysis and material balance was presented. To this end, a decline analysis model derived based on fluid flow mechanisms was proposed and used to analyze the oil production data from. Webbased decline curve analysis solution 216 unconventional reserves estimation 235. Unconventional datadriven methodologies forecast performance in unconventional oil and gas reservoirs keith r.
Decline analysis is a reservoir engineering empirical technique that extrapolates trends in the production data from oil and gas wells. Production decline curve an overview sciencedirect topics. However, the time distribution of active wells as well as temporary shutdowns and similar events. Although decline curve analysis was originally developed for single wells, it can also be applied to entire fields. Holdaway, louis fabbi, and dan lozie, sas institute inc. Analysis of production decline curves digital edition. Similar to conventional wells, future oil and gas production for unconventional wells is often forecasted by fitting a curve through historical production volumes then extrapolating the curve to predict future production, a technique called decline curve analysis dca.
This program is provided by gotech as is and gotech does not fully support this program. This book will serve as an authoritative reference on modern production decline curve analyses, including details of some recent advances in the technology. This chapter presents the various methods of decline curve analysis, the applications, the causes of production decline, factors affecting the decline rate and also the methods of identifying the decline model of. In recent years, production declinecurve analysis has become the most widely used tool in the industry for oil and gas reservoir production analysis. For the oilgas well with edgebottom aquifer, the decline analysis curve can be separated into four stages, which are listed as follows with the corresponding characteristics, as shown in figure 12. There is an overlap between the normalized rate curve and a certain type curve. How to automate decline curve analysis dca in python. Definition of normalized production rate decline, d. Aug 04, 2015 it was also found there are nonlinear relationships between oil incrementals for water flooding step stimulation and step time which different laws with permeability, net pay, and remaining oil saturation and structure place of reservoir in limit period. Download it once and read it on your kindle device, pc, phones or tablets.
A program, and screening data points to calculate remaining and recoverable reserves. By the aid of this knowledge the value of a property may be judged, and proper depletion and depreciation charges may be made on the books of the. Depletion and decline curve analysis in crude oil production. Practical decline curve analysis society of petroleum. The exponential decline is shown to be a longtime solution of the constantpressure case. Here i am going to introduce decline curve analysis through ratetime forecasting.
Pdf production decline curves of tight oil wells in. This includes down time related to facility and well maintenance. Oil and gas reserves can be estimated by identifying and extrapolating the decline characteristics of wells in a field. Decline curve analysis is a long established tool for developing future outlooks. Material balance equatio n decline curve analysis is a reservoir engineering empirical technique that extrapolates the trends in the production data from oil and gas wells. Calculating the estimated ultimate recovery eur using various types of decline curve analysis dca or using rate transient analysis rta is widely used to determine the flow capacity and strength of a well in conjunction with one another to tie back to completions design. Conversely, predictions from the decline history assumes that no significant changes in these factors will take place.
Is a decline curve analysis applicable on individual wells. The traditional decline analysis can also be modified to a terminal limiting decline rate. Study on the decline analysis of oil well stimulation rule. Production declinecurve analyses are the most widely used tool in the industry for oil and gas reservoir production analyses. Decline curve analysis for estimating eurs and ooips. Rate transient analysis rta, also know as advanced decline analysis is a relatively recent development that uses well flowing pressures to characterize well and reservoir. The most popular decline curve is that which represent the decline in the oil or gas. Production decline curves of tight oil wells in eagle ford. Decline curve analysis is the most currently method used available and sufficient 1. Oil well production rate naturally declines with time as the reservoir depletes and pressure drops. In order to properly use decline techniques to forecast oil rates, the waterflood decline correlation period should have the following criteria. However, most curve analysis is done by computers, promoting a blackbox approach to engineering and leaving engineers with little understanding of the fundamentals of decline analysis.
Secondly, if the decline curve analysis is to be used for reserves calculations, the forecast needs reflect a reasonable certainty standard. Production forecasting decline curve analysis petrowiki. A fractional decline curve analysis model for shale gas. Oil well decline modeling using hyperbolicexponential.
1163 840 1317 1288 334 12 592 1397 1389 591 368 1604 820 119 142 838 1518 746 1621 1526 179 1500 679 1107 414 276 475 978 196 1628 1376 147 229 1096 1055 49 1165 714 984 645 1018 1489 135 625 638