Decline curve analysis three basic decline curve equations. Decline curve analysis dca is a graphical procedure used for analyzing declining. Finally, the cumulative recovery should result in a reasonable recovery factor, based on volumetrics. Both type curve fitting and type curve matching techniques will be explained and demonstrated. Decline curve analysis for estimating eurs and ooips. Crains petrophysical handbook reserves from decline curve. Larkey 1925 proposed the leastsquares method to extrapolate the. Quick decline production oil and gas decline analysis. Decline curve analysis help exponential decline curve analysis new features display on chart allows the user to display the decline line on the chart itself decline curve start date when you want the decline curve to be displayed on the chart initial flowrate in the context of the exponential decline curve analysis, this is the flowrate essentially on the first day of production.
To estimate ooip we need to know the estimated ultimate recovery eur and the recovery factor we can get eurdirectly from a graph we use a standardized average recovery factorof 35% for all reservoirs undergoing. Select some leases in the lease tree, then click the summation button and select create summary lease. The effective decline factor d is a stepwise function that is in better agreement with data recording practices. Some of the reservoir factors that affect the decline rate. The theory of all decline curve analysis begins with the concept of the nominal instantaneous decline rate a, which is defined as the fractional change in rate per unit time. The class includes a variety of handson problems, and exposure to modern computerbased decline analysis tools.
The decline curve equations assume that reservoir rock and fluid properties porosity, permeability, formation volume factor. Aug 17, 2015 drillnomics released its oil and gas economic evaluation and decline curve software to the public this quarter, and industry response has been overwhelmingly positive. Petroleum engineers had noticed that oil production fell over time, but they did not have a model to work. But this is where decline curve analysis algorithms are these daysat a fork in the road, and the one you choose to evaluate your. Decline rate or b factor choice can use p90, p50, p10, or another method. The utility of type wells in predicting initial rates and shortmedium term decline does not necessarily depend on the. Quickdecline was written by petroleum engineers as a tool to make quick and easy decisions. The cumulative oil production after the production decline upon decline time t can also be evaluated based on the total reservoir compressibility. Production forecasting decline curve analysis petrowiki. Arps observed that the ratio of production rate to change in production rate played a crucial role in determining the type of decline a well would undergo. With the company growing at a rate of over 50% per month and a free trial to subscriber conversion rate of over 60%, the product is quickly capturing market share.
Provide a name for the new lease, and it will be added to the lease tree. Dm minimum decline rate decline rate at which hyperbolic projection becomes exponential segment null projection pressing this button causes a 0 or null projection to be input for the 1st decline segment. 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. Wells decline curve analysis comparison historical diagnostic analysis is performed by automated curve fitting, then the relevant parameters are used for forecasting. This analysis uses three methods for predicting the deline of a reservoir, exponential, harmonic and hyperbolic. Production declinecurve analysis is accepted for prediction of future performance of oil and. Quick decline ultimate proffesional petroleum decline. L337tech llc also offers paid training for quickdecline.
Black dots represent the outliers, whereas red dots are the oil rates included in the analysis. The nominal decline factor d is defined as the negative slope of the curve. In the equation below, qi initial production rate, qt the production rate at the given time, t time, diinitial decline fraction, b hyperbolic exponent from 0 to 1. Phdwin offers evaluators a tool that combines an intuitive interface with sophisticated functionality. The product will save significant man hours over traditional decline curve analysis software. Conversely, predictions from the decline history assumes that no significant changes in these factors will take place. Dca parameters are easily input to fit your data and forecast production on the fly. Working with decline curves phdwin oil and gas software. New oil and gas economic and decline curve software tool is. Khulud mustafa rahuma pertroleum engineering department tripoli university abstract. For the hyperbolic case, b is equal to any number between zero and one.
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. Wells decline curve analysis comparison historical diagnostic analysis is performed by automated curvefitting, then the relevant parameters are used for forecasting. Cutler 1924 also used the loglog paper to obtain a straight line for hyperbolic decline, so the curve shifted horizontally. The b factor regulates the initial steepness of the decline curve. Mar 11, 2012 quick decline ultimate is a professional oil and gas decline analysis and economic package meant to be affordable to anyone direct competitors like phdwin charge thousands of dollars for a license. I have been successful at calculating the function and solving for q over a range of t values. Decline curve analysis nontechnical, easy read published on august 10, 2016 august 10, 2016 11 likes 0 comments. Vol volume under the curve segment adjusted for historical production. A decline curve analysis model based on fluid flow mechanisms.
A curve fit of past production performance is done using certain standard curves. The hyperbolic curve requires estimation of both di and the exponent b. Practical decline curve analysis society of petroleum. Decline curve analysis is a means of predicting future oil well or gas well production based on past production history. Initial rate and b factor can be fitted to historical production data as best fit, p90, or p10, and commercial software packages are available to. Dynamicforecaster has integrated decline curve analysis software to forecast oil and gas wells. Decline curve analysis free decline curve analysis. A decline curve analysis model based on fluid flow mechanisms kewen li, spe, and roland n. New oil and gas economic and decline curve software tool. Arnold and anderson 1908 presented the first mathematical model of dca. Initial flowrate in the context of the exponential decline curve analysis, this is the flowrate essentially on the first day of production, although the average flowrate for the first full month could also be used.
Decline curve start date when you want the decline curve to be displayed on the chart. When d 0, the equation yields an exponential decline model, and when d 1 the equation is said to be a harmonic model. The remaining reserve calculation becomes more reliable whenever data points are well screening. Prediction of reservoir performance applying decline curve analysis. With inputs for multiple scenarios, running sensitivities on the dca inputs is fast and easy. Phdwin economics and reserves software by trc consultants. The decline curve equations assume that reservoir rock and fluid properties porosity, permeability, formation volume factor, viscosity, and saturation governing the flow. The decline curve analysis template for tibco spotfire allows you to quickly plot oil forecast curves on top of your actual production, using the arps hyperbolic equation. Working with decline curves phdwin economics and reserves. Production decline curve analysis the road not taken. How do you control flow with conidtional statement to.
Quick decline ultimate is a professional oil and gas decline analysis and economic package meant to be affordable to anyone direct competitors like. So, my goal is to modify my analysis in the most efficient manner possible so that beyond a certain point my decline curve declines at such a rate that eventually q 0. Phdwin is a fullfeatured economic and decline curve analysis program. The most popular decline curve is that which represent the decline in the oil or gas. A decline curve analysis dialog was included to allow the user to predict the economic limit for a specific lease, field, operator and county. The equation shows that the respective decline curves are generated based on the value of b. How do you evaluate a function over a range of more than. The b factor determines the initial steepness of the decline curve is. In advanced production decline analysis and application, 2015. Production decline data from different types of waterdrive reservoirs were analyzed as examples of using the new decline analysis model. Drillnomics released its oil and gas economic evaluation and decline curve software to the public this quarter, and industry response has been overwhelmingly positive. The decline type of well 1 is exponential, and the remaining reserve calculated.
For exponential decline it is a constant with time. Jul 05, 2016 production decline curve analysis the road not taken. Calculate ooip using 35% recovery factor if the reservoir has undergone tertiary recovery then also determine the tertiary eur. Harmonic decline is a special case of hyperbolic decline where b 1. But this is where decline curve analysis algorithms are these daysat a fork in the road, and the one you choose to. Practical decline curve analysis society of petroleum engineers. Decline curve analysis is a graphical procedure used for analyzing declining production. This may be the case still, even though ten years have past. The conventional analysis of production decline curves for oil or gas. Decline curve analysis dca is used to predict the future production of oil and gas, and it has been widely used since 1945.
Before the availability of computers, decline curve analysis was performed by hand on semilog. Factors that affect sandface flowing pressure are rate controlled wells, changing. The method can replace graphical or typecurve methods that are tedious and give subjective results. Pro duction prediction based on reservoir simulator 0. The production decline curves have two main functions, including a to determine the reservoir permeability parameter by matching the production decline curve with it, which belongs to quantitative analysis, and b to diagnose the production performance characteristics, that is, to qualitatively judge the flow state, the change of production. Phdwin phdwin economics and reserves software by trc. Fetkovich recognized that decline curve analysis was only applicable during the depletion period ie. For b 1 and as t infinity so does my output q infinity. Rrreeesssererervvvoir engoir engoir engininineeeering for. B oi formation volume factor for oil at initial conditions reservoir bbl barrels stb stock tank barrels from lab data. Decline curve analysis and application to eagle ford production data arps decline curve model. Decline analysis curve an overview sciencedirect topics. Decline curve analysis free decline curve analysis software. Investigation of reservoir production performance using decline curve analysis dr.
A method for estimating reserves and predicting production in oil reservoirs and oil fields. The production decline curves have two main functions, including a to determine the reservoir permeability parameter by matching the production decline curve with it, which belongs to quantitative analysis, and b to diagnose the production performance characteristics, that is, to qualitatively judge the. If you have a fairly fast connection, you may wish to download the entire package. Petroleum engineers, landmen, royalty owners, prospectors, and everyone in between can easily use quick decline to get a leg up on the competition. The more common type curve fitting methods are demonstrated using examples from fields in western canada. In this study decline analysis was applied for wells, and whole field. Hyperbolic decline curves have been used in many cases, particularly in the late history of pressure supported production. The plots can also help you choose which b factor is most appropriate for your well. Mathematics the arps decline curve analysis approach4 was proposed nearly sixty years ago. Phdwin is a fullfeatured, completely integrated economics and decline curve software package written by petroleum engineers for the oil and gas industry. It offers a complete solution to manage, organize, and evaluate reserves and economics. It was a study from arnold and anderson 1908 where for the first time was mentioned the production decline curve.
Quick decline production oil and gas decline analysis and. A decline curve analysis model based on fluid flow. The interpretation results of the numerical model, topaze software, and. Quite simply, i am trying to calculate the value of q given an initial rate qi, a constant b, and a decline rate di at time t. Data points lying outside the type curve represent transient flow. The drillnomics di factor is a similar representation of the initial decline rate in arps and in conjunction with the b factor will enable the user to easily model the hyperbolic section of a decline curve when fitting visually to well production data. Typewell analysis improves decline curve estimation oil. Prediction of reservoir performance applying decline curve. 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. Another way of representing the decline rate is based on rate q and the decline exponent constant b.
The decline curve shows how oil and gas production rates decrease over time. The nominal or instantaneous decline rate, r, of the skin factor, s, is assumed constant, i. Oil and gas decline curves rock river minerals, lp. Both typecurve fitting and type curve matching techniques will be explained and demonstrated. Quick decline ultimate proffesional petroleum decline and. Determine the amount of prior production and add that to the partial eur for the actual estimated ultimate recovery. How can i perform a decline curve analysis on a summary of leases.
The theory of all decline curve analysis begins with the concept of the nominal. Quick decline allows for easy production and well data imports for most of todays modern tools. Decline curve analysis software for oil and gas wells. Methodology and cases for decline curve analysis sciencedirect. A b factor is a hyperbolic exponent used in the arps decline curve equation to model either. Oil and gas reservoir and economic analysis software. Decline curve analysis is the most currently method used available and sufficient 1.