Interference effects among wells produced at constant pressure
Although there are numerous techniques for analyzing pressure interference effects for constant rate wells, the analogous rate transients due to interference among constant pressure producers have never been investigated in detail. The transient pressure behavior resulting from interference effects among wells produced at constant rates can be determined in a straightforward manner using the principle of superposition in space. For constant pressure producers, the flow rates are continuously changing. Hence, the pressure interference among constant pressure wells cannot be determined in the conventional way. In this study, the rate interference among constant pressure production wells is modeled using the diffusivity equation. Pressure distributions in the reservoir for both constant pressure and constant rate couplets were obtained. The two are qualitatively similar and exhibit a similar zone of zero pressure gradient, which confirms the existence of an apparent no-flow boundary between any two constant pressure producers analogous to the one that is known to exist between wells flowing at constant rate. Results also show that a nearby fault boundary can be detected in a drawdown well test as the doubling of the slope of the semi-log straight line produced when the reciprocal of the flow rate is graphed versus the log of time. Another principal function of modern well testing is to evaluate the formation anisotropies. The method given by Ramey for the constant rate environment does not fully hold for the constant pressure setting. Therefore, a new method for evaluating directional permeabilities has been developed. To demonstrate the theory in application, example problems have been worked explaining and emphasizing the practical applications of the new techniques.
- Research Organization:
- Univ. of Alaska, Fairbanks
- OSTI ID:
- 5458555
- Report Number(s):
- CONF-8305148-
- Journal Information:
- Soc. Pet. Eng. AIME, Pap.; (United States), Vol. SPE11715; Conference: Rocky Mountain regional meeting of the Society of Petroleum Engineers, Salt Lake City, UT, USA, 22 May 1983
- Country of Publication:
- United States
- Language:
- English
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