GASWAT-PC: A Microcomputer Program for Gas Material Balance With Water Influx

Author(s):  
B. Wang ◽  
T.S. Teasdale
1992 ◽  
Vol 4 (05) ◽  
pp. 8-19 ◽  
Author(s):  
Ben Wang ◽  
B.L. Litvak ◽  
G.W. Bowman

Author(s):  
Tri Handoyo ◽  
Suryo Prakoso

<em>The success of the discovery of new structure Akasia Bagus with potential L layer in 2009 at PT Pertamina EP's Jatibarang Field was followed up by the drilling infill wells with Plan of Development (POD) mechanism which is currently in the process of drilling the last well. The basis of the L layer hydrocarbon calculation in place on the POD is a static analysis. The wells currently produced are still able to flow with natural flow and enough production data since 2009 this structure was found. This study will present an analysis of production in the L layer of Akasia Bagus structure for Original Oil In Place (OOIP) updates using the conventional material balance method and then carry out the best development strategy to optimize oil production. Economic analysis is also carried out for reference in making decision on which scenario to choose. The conventional material balance method gets an OOIP value of 17.36 MMSTB, with the drive energy ratio being 5:3:2 for water influx : fluid expansion : gas cap expansion. Three (3) production optimization scenarios were analyzed, the results showed that the addition of 2 infill wells reached Recovery Factot (RF) of oil up to 23% of OOIP, minimal water production and attractive economic results.</em>


2016 ◽  
Vol 5 (2) ◽  
pp. 18-32
Author(s):  
Ira Herawati

Primary recovery is the stage of oil production by relying on the natural ability of the driving force of the reservoir. Kind of driving force that is water drive reservoir, depletion drive, segregation drive and a combination drive. The pressure drop occurred along its produced oil from the reservoir. Reservoir so that the driving force is the main parameter in maintaining reservoir pressure balance. Through the concept of material balance is the determination of the type of propulsion quifer reservoir and the power that generates driving force parameter analysis capability and aquifer in oil producing naturally. Then do the forecasting production to limit the ability of primary recovery production phase. Combination drive depletion of water drive and the drive is a driving force in the dominant reservoir Falipu Fields with a strongly water aquifer types of drives obtained through material balance equation. Calculations using the method of water influx Havlena & Odeh used as a correction factor for determining the type of propulsion reservoir and aquifer strength. Forecasting production in the Field Falipu generate recovery factor of 41% with a pressure boundary in 2050.


2013 ◽  
Vol 2 (2) ◽  
pp. 24-27
Author(s):  
Novrianti Novrianti

Water Influx adalah air yang merembes ke dalam reservoir. Water Influx terjadi untuk mengimbangi gejala penurunan tekanan yang terjadi di reservoir karena masuknya air berfungsi untuk menggantikan minyak yang diproduksikan. Water Influx perlu diperhatikan untuk mengetahui luas aquifer serta pengaruhnya terhadap tingkat perolehan ( recovery factor). Lapangan X mulai produksi tahun 1955 dan injeksi air mulai dilakukan tahun 1974. Estimasi perhitungan Water influx pada lapangan X dilakukan dengan menggunakan persamaan  material balance dan metode Hurst – Van Everdingen. Selain menentukan Water influx metode Hurst – Van Everdingen juga berfungsi untuk menentukan bentuk dan luas aquifer. Kumulatif water influx yang diperoleh dengan menggunakan Metode Material Balance adalah 30 MMMSTB  sedangkan dengan metode Hurst – Van Everdingen adalah 32 MMMSTB. Bentuk aquifer lapangan X adalah  finite aquifer dengan rD = 8  dan Luas aquifer lapangan  X adalah 241016,62 ft.


1983 ◽  
Vol 23 (02) ◽  
pp. 209-218 ◽  
Author(s):  
J.S. Rodgers ◽  
R.S. Boykin ◽  
L.E. Coble

Abstract A method has been developed for using nonstatic pressure measurements directly in gas reservoir material balances composed of various energy mechanisms. Applying this method leads to simultaneous determinations of the reservoir p history, gas in place, and other parameters relevant to water influx and effective compressibility. Well-known methods of determining average static pressure, p, have at least two shortcomings:an estimation of reservoir shape andan often-neglected implicit relationship between p and the viscosity-compressibility product. Errors resulting from these deficiencies are minimized by the proposed method through a simple coupling of the well-known pseudo steady-state flow and material-balance equations. The solution of this coupling is obtained through nonlinear regression, and it allows simultaneous evaluations of gas initially in place, static pressure history, and several other reservoir parameters. These parameters can include the initial reservoir pressure, a stabilized gas-deliverability constant, the effective compressibility, aquifer diffusivity, and aquifer volume plus water-influx constants. The results of applying the method to six published cases are presented to illustrate the utility of the method. Introduction Before performing material-balance calculations, separate determinations of the average static reservoir pressure history from available drawdown and buildup tests and shut-in or flowing gradient surveys were required. Well-known methods used for these determinations have been shown by Matthews et al., Odeh and Al-Hussainy, Brons and Miller, and Dietz. All these methods for determining p have one or more undesirable requirements such as a preknowledge of the hydraulic diffusivity in terms of the reservoir area and the reservoir boundary shape plus the assumption of a volumetric depletion-type reservoir-drive mechanism. An additional drawback is found in the implicit relationship between p and the viscosity-compressibility product of the dimensionless time parameter. This product must be evaluated at p in the aforememtioned methods; therefore, the solution of p is implicit. Kazemi has discussed this problem for both oil and gas cases. The proposed method eliminates the intermediate steps in determining a p history before calculating material balances, and it does not require a preknowledge of the hydraulic diffusivity, boundary shape, or reservoir-drive mechanism. Part of the original development work on this problem was presented by Garb et al. This publication showed an iterative method that coupled the functional p terms of the material-balance and the pseudosteady-state flow equations for drawdown and buildup cases. However, the method was limited to determining only gas initially in place for normalpressured, nonwater-drive reservoirs. The new development formulates the problem in a different manner to obtain nonlinear solutions in various reservoir-drive mechanisms. This method eliminates the prerequisite of p determinations, and it provides simultaneous solutions of gas initially in place, p history, water influx, and effective rock and connate water compressibilities. SPEJ P. 209^


PETRO ◽  
2018 ◽  
Vol 5 (1) ◽  
Author(s):  
Eoremila Ninetu Hartantyo ◽  
Lestari Said

<div class="WordSection1"><p><em>The purpose of this thesis is to calculate the original oil in place of ENH zone in X field. There are two methods to calculate the original oil in place of ENH zone, which is volumetric method and material balance method. From the calculation of original oil in place of ENH zone using volumetric method is 5.860.310 STB.</em></p><p><em>In Havlena - Odeh straight line material balance method needs the number of water influx. The water influx can be determine using Van-Everdingen Hurst method. The constant number of water influx of ENH zone is 311 BBL/psia. The original oil in place calculation of ENH zone using material balance method is 6.000.000 STB. Decline curve analysis is a method to determine the production performance and estimate ultimate recovery (EUR). By knowing the economic limit rate of ENH zone at 40 BOPD, it can be searched the oil rate and cumulative oil production of ENH zone. The economic limit rate of ENH is reached in March 2019 with recovery factor at 57,95%.</em></p><p><em>Keywords: original oil in place, volumetric, material balance, decline curve analysis</em></p></div>


2020 ◽  
Vol 143 (8) ◽  
Author(s):  
Angang Zhang ◽  
Zifei Fan ◽  
Lun Zhao ◽  
Jincai Wang ◽  
Heng Song

Abstract Material balance is a basic principle in reservoir engineering, which is still used as a quick and easy analytical tool for reservoir evaluation. In this article, a new methodology of production performance prediction for water-flooding reservoir was proposed based on the material balance principle, which considers the water saturation change caused by water injection and natural water influx, and its effect on transient gas–oil ratio. Among them, the cumulative water production was calculated based on Tong’s water-driver performance curve; the cumulative water influx was obtained by the Fetkovitch method; the transient gas–oil ratio can be acquired by Darcy’s law and Baker’s relative permeability model. Comparisons have been made between the new methodology and commercial reservoir simulator for two different reservoirs. The results show that there is good similarity between these two tools, which verifies the correctness of the new methodology.


1962 ◽  
Vol 2 (02) ◽  
pp. 120-128 ◽  
Author(s):  
C.R. Mcewen

Abstract This paper presents a technique for calculating the original amount of hydrocarbon in place in a petroleum reservoir, and for determining the constants characterizing the aquifer performance, based on pressure-production data. A method for doing this based on a least-squares line-fitting computation was proposed by van Everdingen, Timmerman and McMahon in 1953. We found that their method would not work when there is error in the reservoir pressure dataeven moderate error. The technique presented here appears to give reasonable answers when pressure data are uncertain to the degree expected in reservoir pressure determinations. The major change introduced in the present analysis is to limit the least-squares line-fitting to yield only one constant the amount of hydrocarbon in place. The water-influx constant is then taken as proportional to the oil (or gas) in place. The constant of proportionality can be computed from estimates of effective compressibility and reservoir water saturation. It is also pointed out that the commonly used least-squares analysis assumes all of the uncertainty to be in the dependent variable. The material balance should be arranged so that this condition is fulfilled if correct inferences are to be made from statistical calculations. Examples are shown of the application of the new technique to gas reservoirs both hypothetical and real and to the oil reservoir example of van Everdingen, Timmerman and McMahon. Introduction The amount of hydrocarbon originally in place in a petroleum reservoir can be estimated by means of the material-balance calculation. Simultaneous observations of pressure and amounts of produced fluids are required, together with the PVT data applicable to the reservoir fluids. If water encroachment is occurring, it is desirable to try to infer the behavior of the aquifer, as well as the original hydrocarbon in place, from the pressure-production data. This imposes additional demands on the method of calculation, and uncertainty in the data can result in large uncertainty in the answer. In addition, if the size of a gas cap is to be established, the whole problem becomes indeterminate, as pointed out by Woods and Muskat. Brownscombe and Collins simulated a gas reservoir and its aquifer on a reservoir analyzer and derived quantitative information on the effect of uncertainty in pressure and aquifer permeability on computed gas in place. Among the various techniques of estimating the performance of an aquifer, the method of van Everdingen and Hurst, based on compressible flow theory, seems to have been the most generally successful (see Ref. 4, for example). In this paper we shall confine ourselves to their representation of the aquifer. In 1953, van Everdingen, Timmerman and McMahon introduced a statistical technique for deriving the amount of oil originally in place and the parameters which describe the aquifer. (We shall refer to this technique as the "VTM method", as suggested by Mueller.) Their example reservoir had no gas cap. It has been our experience that the VTM method gives a reasonable answer when the data are very accurate, but that inaccuracy (particularly in pressure) can cause the method to break down. The effect was first observed in gas reservoirs, but has since been seen in oil reservoirs also. In this paper we present another statistical method which has been successful in achieving a reasonable answer where the VTM method has failed. In the new method, one less parameter is derived from material-balance computations. It is assumed that values can be established for effective compressibility in the aquifer and reservoir water saturation independently of the material-balance calculation. The water-influx constant can then be obtained from these data and the quantity hydrocarbon in place. SPEJ P. 120^


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