Changes

==Interference and pulse tests==

==Interference and pulse tests==

Interference and pulse tests are run to obtain the following information:

Interference and pulse tests are run to obtain the following information:

* Directional permeabilities between tested well pairs

* Directional permeabilities between tested well pairs

* Average porosities in the areas influenced by the tests

* Average porosities in the areas influenced by the tests

===How the tests are run===

===How the tests are run===

Interference tests are run by first shutting in the portion of the reservoir in the area affected by the test. Then one produces (or injects into) one well (called the active well) and measures the pressure response in the offset wells. Figure 9 shows a typical interference test pattern, and Figure 10 is a plot of a typical response in an observation well.

Interference tests are run by first shutting in the portion of the reservoir in the area affected by the test. Then one produces (or injects into) one well (called the active well) and measures the pressure response in the offset wells. [[:file:pressure-transient-testing_fig9.png|Figure 9]] shows a typical interference test pattern, and [[:file:pressure-transient-testing_fig10.png|Figure 10]] is a plot of a typical response in an observation well.

 

[[file:pressure-transient-testing_fig9.png|thumb|{{figure number|9}}Active and observation wells in an interference pulse test. (After <ref name=pt09r7>Earlougher, R. C., Jr., 1977, Advances in Well Test Analysis: Dallas, TX, American Institute of Mining, Metallurgical and Petroleum Engineers, Society of Petroleum Engineer's Monograph 5, 264 p.</ref>.)]]

 

[[file:pressure-transient-testing_fig10.png|thumb|{{figure number|10}}Schematic illustration of rate history and pressure response for an interference test. (After <ref name=pt09r7 />.)]]

Pulse tests are performed by first producing (or injecting into) the active well for a few hours. The active well is then shut-in, then returned to production, shut-in again, and so on in a regular, repeating pattern. The response in the offset wells is then measured while continuing to produce all wells in the field except those directly involved in the test. This is possible because the “noise” caused by continued production of wells not directly involved in the test can be filtered out using the response caused by the repeated on-off pattern in the active well. Figure 11 shows a typical response in a pulse test observation well.

[[file:pressure-transient-testing_fig11.png|left|thumb|{{figure number|11}}Schematic Illustration of rate (pulse) history and pressure response for a pulse test.<ref name=pt09r7 />]]

[[file:pressure-transient-testing_fig11.png|thumb|{{figure number|11}}Schematic Illustration of rate (pulse) history and pressure response for a pulse test. (After <ref name=pt09r7 />.)]]

Pulse tests are performed by first producing (or injecting into) the active well for a few hours. The active well is then shut-in, then returned to production, shut-in again, and so on in a regular, repeating pattern. The response in the offset wells is then measured while continuing to produce all wells in the field except those directly involved in the test. This is possible because the “noise” caused by continued production of wells not directly involved in the test can be filtered out using the response caused by the repeated on-off pattern in the active well. [[:file:pressure-transient-testing_fig11.png|Figure 11]] shows a typical response in a pulse test observation well.

===Comparison of pulse and interference tests===

===Comparison of pulse and interference tests===