Decline Curve Analysis for Unconventional Reservoir Systems -- Variable Pressure Drop Case

Determining the reliable values of the filtration parameters of productive reservoirs is the most important task in monitoring the processes of reserve production. Hydrodynamic studies of wells by the pressure build-up method, as well as a modern method based on production curve analysis (Decline Curve Analysis (DCA)), are some of the effective methods for solving this problem. This paper is devoted to assessing the reliability of these two methods in determining the filtration parameters of terrigenous and carbonaceous productive deposits of oil fields in the Perm Krai. The materials of 150 conditioned and highly informative (obtained using high-precision depth instruments) studies of wells were used to solve this problem, including 100 studies conducted in terrigenous reservoirs (C1v) and 50 carried out in carbonate reservoirs (C2b). To solve the problem, an effective tool was used—multivariate regression analysis. This approach is new and has not been previously used to assess the reliability of determining the filtration parameters of reservoir systems by different research methods. With its use, a series of statistical models with varying degrees of detail was built. A series of multivariate mathematical models of well flow rates using the filtration parameters determined for each of the methods is constructed. The inclusion or non-inclusion of these filtration parameters in the resulting flow rate models allows us to give a reasonable assessment of the possibility of using the pressure build-up method and the DCA method. All the constructed models are characterized by high statistical estimates: in all cases, a high value of the determination coefficient was obtained, and the probability of an error in all cases was significantly less than 5%. As applied to the fields under consideration, it was found that both methods demonstrate stable results in terrigenous reservoirs. The permeability determined by the DCA method and the pressure build-up curve does not control the flow of the fluid in carbonate reservoirs, which proves the complexity of the filtration processes occurring in them. The DCA method is recommended for use to determine the permeability and skin factor in the conditions of terrigenous reservoirs.

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CALCULATION METHODS OF VARIABLE PRESSURE-DROP FLOWMETERS ACCURACY IMPROVEMENT

Scientific Papers Collection of the Angarsk State Technical University ◽

10.36629/2686-7788-2018-1-1-88-92 ◽

2018 ◽

Vol 1 (1) ◽

pp. 88-92

Author(s):

I.L. Ilina ◽

◽

A.I. Noskova ◽

Keyword(s):

Pressure Drop ◽

Variable Pressure ◽

Calculation Methods ◽

Accuracy Improvement ◽

Variable Pressure Drop

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Evaluation of natural gas production optimization in Kailashtila gas field in Bangladesh using decline curve analysis method

Bangladesh Journal of Scientific and Industrial Research ◽

10.3329/bjsir.v50i1.23807 ◽

2015 ◽

Vol 50 (1) ◽

pp. 29-38 ◽

Cited By ~ 1

Author(s):

MS Shah ◽

HMZ Hossain

Keyword(s):

Production System ◽

Gas Production ◽

Curve Analysis ◽

Production Optimization ◽

Reservoir Pressure ◽

Gas Field ◽

Wellhead Pressure ◽

Decline Curve Analysis ◽

Decline Curve ◽

Overall Performance

Decline curve analysis of well no KTL-04 from the Kailashtila gas field in northeastern Bangladesh has been examined to identify their natural gas production optimization. KTL-04 is one of the major gas producing well of Kailashtila gas field which producing 16.00 mmscfd. Conventional gas production methods depend on enormous computational efforts since production systems from reservoir to a gathering point. The overall performance of a gas production system is determined by flow rate which is involved with system or wellbore components, reservoir pressure, separator pressure and wellhead pressure. Nodal analysis technique is used to performed gas production optimization of the overall performance of the production system. F.A.S.T. Virtu Well analysis suggested that declining reservoir pressure 3346.8, 3299.5, 3285.6 and 3269.3 psi(a) while signifying wellhead pressure with no changing of tubing diameter and skin factor thus daily gas production capacity is optimized to 19.637, 24.198, 25.469, and 26.922 mmscfd, respectively.Bangladesh J. Sci. Ind. Res. 50(1), 29-38, 2015

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