TABLE OF CONTENTS When the flow rate is changed and the pressure response is recorded in the same well, the test is called a single-well test. Examples of single-well tests are drawdown, buildup, injectivity, falloff and step-rate tests. When the flow rate is changed in one well and the pressure response is recorded in another well, the test is called a multiple-well test. Examples of multiple-well tests are interference and pulse tests.
Single-well tests provide valuable reservoir and well characteristics that include flow capacity kh, wellbore conditions, and fracture length as examples of these important properties. However, these tests do not provide the directional nature of reservoir properties (such as permeability in the x, y, and z direction) and have inabilities to indicate the degree of communication between the test wells and adjacent wells. Multiple-well tests are run to determine:
the presence or lack of communication between the test well and surrounding wells;
the mobility thickness product kh/ ?;
the porosity compressibility thickness product 
c t h;
the fracture orientation if intersecting one of the test wells;
the permeability in the direction of the major and minor axes.
The multiple-well test requires at least one active (producing or injecting) well and at least one pressure observation well, as shown schematically in Figure 1.98. In an interference test, all the test wells are shut-in until their wellbore pressures stabilize. The active well is then allowed to...
