New Methods for the Analysis of Closed-Chamber Tests

Abstract

ABSTRACT A closed chamber test (CCT) is characterized by a variable wellbore storage coefficient, whereas, in a slug test, the wellbore storage coefficient is assumed to be constant. It is shown that for ranges of parameters often encountered in practical cases, a large span of the CCT pressure data can be converted to equivalent slug test pressure data which can then be analyzed by several available slug test analysis techniques. In addition, we derive a new convolution method for analyzing buildup data obtained in a closed chamber drillstem test. We also present a method to analyze slug test data influenced by a step change in the wellbore storage coefficient due to a change in the well-string diameter.