A drill stem test dst is some form of temporary completion of a well that is designed to determine the productivity and fluid properties prior to completion of the well. Drill stem tests dsts often provide unexpected or incongruous results when compared with data obtained from electric well logs, samples, andor cores. Drillstem testing dst is one of the most important completion techniques. Step 2 check data axis orientation time is horizontal axis and temperature and pressure are vertical axis, which is. Analysis of flowing dsts is less complicated because flow rates can be measured throughout the test. Commonly, dst recoveries from damaged productive zones consist of a combination of gas at low producing rates, oil or gas cut drilling mud, or mud filtrate water. Principal drill stem test database ubdst and documentation.
Pdf analysis of drill stem test dst results at osobnica oil field. A drill stem test dst is a procedure for testing the wellbore pressure. Drillstem testing dst is one of the most important completion technique s. A drillstem test, or dstdrill stem test, is the most common method to measure reservoir pressure. It is a type of temporary completion that is used to evaluate the formation and inspect a reservoirs properties. A drill stem test dst is some form of temporary completion of a well that is. Pdf analysis of drill stem test john ansa academia. Drillstem testing archives rubicon oilfield international. Onshore dst test string bourdet, 2001 analysis of drill stem test page 1. Although a dst can be performed in uncased hole open hole or in cased hole perforation tests, the open hole test is more common. Drill stem tests dsts often provide unexpected or incongruous results when compared with data obtained from electric well logs, samples. Practical considerations of drillstem test interpretation. Analysis of 78 drillstem tests dst from oil and gas wells in the uinta basin. Formation fluid pressure from drill stem tests aapg wiki.
Drillstem test data analysis considering inertial and. Drill stem test dst free download as powerpoint presentation. Joint photographic experts group or gif graphics interchange format image file. Drill stem test dst a drill stem test is a test which uses a special tool mounted on the end of the drill string. It is a test commonly used to test a newly drilled well. The combination of the drillpipe, the bottomhole assembly and any other tools used to make the drill bit turn at the bottom of the wellbore. There are essentially no standard ascii dst data files formats existing that will allow the user to read and process dst data. After the operator determines that a formation test is to be conducted, the test tool is assembled and lowered into the wellbore. Practical considerations of drillstem test interpretation of damaged. Dsts are the most reliable reservoir pressure measurement method if sufficient time elapses during the test for the higher formation pressure to equilibrate with the lower borehole pressure. Drill stem testing follows the basic principles of mechanics, hydromechanics, common sense and practicability.
Total lest times are approximately twenty four hours while on bottom test times average six hours. Open hole drill stem tests dits are conducted with a drilling rig in open hole hence the name. Pdf in the paper results of dst tests obtained in two wells at osobnica oil field are presented. The zone in question is sealed off from the rest of the wellbore by packers, and the formations pressure and fluids are measured. Drill stem test dst valve petroleum reservoir scribd. A low recovery on a test may be the result of damage rather than poor producing abil. It is a type of temporary completion that is used to evaluate the formation and inspect a reservoir s properties. This seminar paper will present methods for the quantitative analysis of drill stem test.