Changes

[[file:production-testing_fig1.png|left|thumb|{{figure number|1}}Typical drill stem test pressure chart. (From <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:production-testing_fig1.png|left|thumb|{{figure number|1}}Typical drill stem test pressure chart. (From <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>.)]]

Drill stem tests (DSTs) are used to obtain (1) samples of the reservoir fluid, (2) measurements of static bottomhole pressure, (3) an indication of well productivity, and (4) short-term flow and pressure buildup tests from which [[permeability]] and the extent of damage or stimulation can be estimated<ref name=pt09r14>Lee, W. J., 1982, Well Testing: Dallas, TX, Society of Petroleum Engineers of AIME, 159 p.</ref>. A DST is run in the open hole after drilling, and is often used in deciding whether to complete a particular zone. The total test duration is frequently a function of hole condition, and the tool assembly must be retrieved from the open hole after the test is completed (see “[[Drill stem testing]]”).

Drill stem tests (DSTs) are used to obtain (1) samples of the reservoir fluid, (2) measurements of static bottomhole pressure, (3) an indication of well productivity, and (4) short-term flow and pressure buildup tests from which [[permeability]] and the extent of damage or stimulation can be estimated.<ref name=pt09r14>Lee, W. J., 1982, Well Testing: Dallas, TX, Society of Petroleum Engineers of AIME, 159 p.</ref> A DST is run in the open hole after drilling, and is often used in deciding whether to complete a particular zone. The total test duration is frequently a function of hole condition, and the tool assembly must be retrieved from the open hole after the test is completed (see [[Drill stem testing]]).

To run a drill stem test, a special DST tool is attached to the drill pipe and run in the hole opposite the zone to be tested. A DST tool typically includes two or more clock-driven, bourdon-tube recording pressure gauges, a set of flow valves, and one or two packers. The tool isolates the formation from the mud column in the annulus. When the tool is opened, reservoir fluid can flow into the drill pipe (and possibly to the surface); pressure is recorded continuously during the test.

To run a drill stem test, a special DST tool is attached to the drill pipe and run in the hole opposite the zone to be tested. A DST tool typically includes two or more clock-driven, bourdon-tube recording pressure gauges, a set of flow valves, and one or two packers. The tool isolates the formation from the mud column in the annulus. When the tool is opened, reservoir fluid can flow into the drill pipe (and possibly to the surface); pressure is recorded continuously during the test.