Real time pressure transient analysis methods applied to wireline formation test data
The primary objective of wireline formation testing is to estimate formation pressure and permeability from short duration transient well tests. This paper demonstrates new real time pressure transient analysis methods which may be used during testing to estimate permeability and pressure. These new plots may also be used to determine when sufficient data has been acquired for accurate pressure and permeability determination. Additionally, for tight zones with permeability less than 1 millidarcy, new methods and special plots are presented for interpretation of real time data obtained during the initial drawdown and buildup times. For tight zones the early time data may be distorted by flowline storage effects and is normally ignored by traditional well test analysis techniques. New methods are given in this paper for estimating the compressibility of the actual fluid within the flowlines and chambers of the tester during each test, and this value for compressibility is used in each real time model. A full 3D finite element near wellbore simulator (NEWS) that represents an exact solution is used to show that these new plots give the same values of permeability and pressure as would be obtained from very long buildup times using conventional analysis methods. The tight zone analysis substantially reduces the time required to test tight formations and utilizes data obtained within the optimal dynamic range of pressure transducers.
- OSTI ID:
- 170058
- Report Number(s):
- CONF-941185--
- Country of Publication:
- United States
- Language:
- English
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