Analytical Model for Rate Transient Analysis in Low-Permeability Volatile Oil Reservoirs

2019 ◽  
Author(s):  
Le Luo ◽  
Shiqing Cheng ◽  
John Lee
Keyword(s):  
Analytical Model ◽  
Transient Analysis ◽  
Volatile Oil ◽  
Oil Reservoirs ◽  
Low Permeability ◽  
Rate Transient Analysis

Applying Rate Transient Analysis (RTA) to integrate geological and engineering data

2013 ◽  
Vol 53 (2) ◽  
pp. 473
Author(s):  
Nicholas Kwok
Keyword(s):  
Transient Analysis ◽  
Initial Pressure ◽  
Low Permeability ◽  
Late Time ◽  
Reservoir Pressure ◽  
Potential Consequence ◽  
Time Data ◽  
Engineering Data ◽  
Rate Transient Analysis ◽  
Measured Property

The Blasingame typecurve in Fekete’s Rate Transient Analysis (RTA) software has been used at Santos to increase the understanding and integration of well and reservoir data; however, the authors have discovered that in some cases the tool produced anomalous results, such as permeability being too low. The potential consequence of this was incorrectly writing off reserves or making projects (in particular compression projects) fail economic tests. After testing various hypotheses, a simple yet unorthodox solution was only discovered in a field where the anomaly was more profound, and required integrating geology and geophysics to explain it. This solution has since been applied in RTA models across numerous other fields, and it has improved the quality and confidence of these models. The solution was the realisation that in many cases the accessed gas in place (GIP) increased over time, but the underlying model in RTA assumes a single tank, linear P/z. Matching the RTA model with the initial reservoir pressure and final accessed GIP results in over-predicting the reservoir pressures, resulting in an artificially low permeability. The authors discovered that the appropriate well and reservoir parameters could be obtained by matching the late time data using a lower initial reservoir pressure value corresponding to when the well had accessed the final GIP volume but not the initial reservoir pressure. This step was initially regarded to be counter-intuitive as the initial pressure is a measured property. Numerous reviews have endorsed this methodology, which is now being used as a standard at Santos.

scholarly journals Rate Transient Analysis for Multistage Fractured Horizontal Well in Tight Oil Reservoirs considering Stimulated Reservoir Volume

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Ruizhong Jiang ◽  
Jianchun Xu ◽  
Zhaobo Sun ◽  
Chaohua Guo ◽  
Yulong Zhao
Keyword(s):  
Transient Analysis ◽  
Horizontal Well ◽  
Superposition Principle ◽  
Oil Reservoirs ◽  
Tight Oil ◽  
Stimulated Reservoir Volume ◽  
Reservoir Volume ◽  
Rate Transient Analysis ◽  
Fractured Horizontal Well ◽  
Tight Oil Reservoirs

A mathematical model of multistage fractured horizontal well (MsFHW) considering stimulated reservoir volume (SRV) was presented for tight oil reservoirs. Both inner and outer regions were assumed as single porosity media but had different formation parameters. Laplace transformation method, point source function integration method, superposition principle, Stehfest numerical algorithm, and Duhamel’s theorem were used comprehensively to obtain the semianalytical solution. Different flow regimes were divided based on pressure transient analysis (PTA) curves. According to rate transient analysis (RTA), the effects of related parameters such as SRV radius, storativity ratio, mobility ratio, fracture number, fracture half-length, and fracture spacing were analyzed. The presented model and obtained results in this paper enrich the performance analysis models of MsFHW considering SRV.

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