| Autor: |
A.B. Johnson, I.C. Walton, L.A. Behrmann, K. Hughes |
| Rok vydání: |
2002 |
| Předmět: |
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| Zdroj: |
All Days. |
| DOI: |
10.2118/77364-ms |
| Popis: |
Cased and cemented horizontal wells in the East Painter field in Wyoming have historically been perforated with modest underbalance pressures of 300 to 600 psi and then acid-stimulated to achieve economical production rates. The moderate success rate and expensive acid stimulations provided the motivation to evaluate other options for obtaining cleaner perforations. Conventional perforation-design techniques suggested that an underbalance of about 4000psi is needed to produce clean perforations for the low-permeability rock in this field. This would require a low wellbore pressure. An alternative is to use the PURE* (Perforating for Ultimate Reservoir Exploitation) system to create a high dynamic underbalance from a modest initial under or over balance. Two laboratory tests were conducted to evaluate these alternatives. The knowledge gained from these and other laboratory tests was used to modify the perforating techniques in the East Painter field to increase well production. Perforating gun design was changed, and the perforating process was modified to provide a substantial dynamic underbalance with only a modest initial underbalance. This new dynamic underbalance concept provides transient underbalances up to about 80 percent of the reservoir pressure without applying the equivalent static initial underbalance. This technique increased well performance, and eliminated the costly acid stimulation step by generating cleaner perforations and higher effective shot density. In this paper, details of the gun modifications and perforating process will be described along with specific well-performance data. Comparisons to previous perforating practices are also included. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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