A Well-Test Analysis Method Accounting for Pre-Test Operations
| Autor: | C.-F. Tsang, D. B. Silin |
|---|---|
| Rok vydání: | 2003 |
| Předmět: |
Asymptotic analysis
Hydraulics Computer science Energy Engineering and Power Technology Interval (mathematics) Geotechnical Engineering and Engineering Geology Field (computer science) law.invention law Feature (computer vision) Statistics Code (cryptography) Minification Algorithm Dimensionless quantity |
| Zdroj: | SPE Journal. 8:22-32 |
| ISSN: | 1930-0220 1086-055X |
| Popis: | We propose to use regular monitoring data from a productionor injection well for estimating the formation hydraulic properties inthe vicinity of the wellbore without interrupting the operations. In ourapproach, we select a portion of the pumping data over a certain timeinterval and then derive our conclusions from analysis of these data. Adistinctive feature of the proposed approach differing it formconventional methods is in the introduction of an additional parameter,an effective pre-test pumping rate. The additional parameter is derivedbased on a rigorous asymptotic analysis of the flow model. Thus, weaccount for the non-uniform pressure distribution at the beginning oftesting time interval caused by pre-test operations at the well. Bysynthetic and field examples, we demonstrate that deviation of thematching curve from the data that is usually attributed to skin andwellbore storage effects, can also be interpreted through this newparameter. Moreover, with our method, the data curve is matched equallywell and the results of the analysis remain stable when the analyzed datainterval is perturbed, whereas traditional methods are sensitive to thechoice of the data interval. A special efficient minimization procedurehas been developed for searching the best fitting parameters. We enhancedour analysis above with a procedure of estimating ambient reservoirpressure and dimensionless wellbore radius.more » The methods reported herehave been implemented in code ODA (Operations Data Analysis). A betaversion of the code is available for free testing and evaluation tointerested parties.« less |
| Databáze: | OpenAIRE |
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