One or more pressure gauges are customarily mounted into the dst tool and are read and interpreted after the test. This an illustration of the surface control equipment layout. Data attainable from a drill stem test dst duration. New technology drill stem testing technology expro. Drill stem testing drill stem test dst is used primarily to determine the fluids present in a particular formation and the rate at which they can be produced. 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. This java applet allows the user to enter or import drill stem test dst data directly into the program. Drill stem testing dst is one of the most important completion technique s. Each year, the offshore technology conference otc recognizes. Dst tcp drill stem testing tubing conveyed perforating. The zone in question is sealed off from the rest of the wellbore by packers, and the formations pressure and fluids are measured. Conventional drillstem testing dst is a proven and costeffective means of evaluating a well. Drillstem testing dst permits flow from the test zone to the surface, where the fluid is analysed.
The dst data includes permeability, quality codes, drill. Highly deviated horizontal wells where transmitting torque downhole is problematic. The list of acronyms and abbreviations related to dst drill stem testing. Although a dst can be performed in uncased hole open hole or in cased hole perforation tests, the open hole test is more common. Various types of surface pressure tests usually for gas wells. A drill stem test is the temporary completion of a well to gather reservoir data. A drill stem test, or dst drill 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 reservoir s properties. One of the most important stages of completing a well is discussed in this report which is the drillstem testing dst. The data derived from the drill stem test dst give a computation of the formations permeability, damage ratio, productivity index, transmissibility and radius of investigation. There are six products that are part of the rezconnect offering.
Use to calibrate logs only if zone is not fractured, has not been stimulated, and. Testing system combines advantages of wire line and drill. This data is also used to calculate bottomhole pressures 3. Drill stem testing ets design drill stem test dst jobs to achieve your test objectives economically. Equation box adobe pdf format54,102 bytes a new early formation pressure system efps combines the advantages of a drill stem test dst and a wire line formation tester wft and provides a. Expro is one of the most experienced international well testing companies in the world and an established provider of drill stem testing dst services to the oil and gas industry. Pro test has a high rate of successful tests, a key measure of performance and the.
Flexibility in the dst string design gives you reservoir information from multiple zones on the same test, saving rig time and allowing you to update your reservoir model sooner. What is a drill stem test dst and what data is attainable. Accurate down hole pressure measurements, even under very hostile. As originally conceived, a drillstem test provided primarily an indication of formation content. A drill stem test dst is a procedure for testing the wellbore pressure, permeability and productivity of a geological formation during the drilling of a well. Pdf analysis of drill stem test dst results at osobnica oil field. It is a type of temporary completion that is used to evaluate the formation and inspect a reservoirs properties. Drillstem testing dst is one of the most important completion techniques. Very, very common test so learn about them used to determine formation permeability boundary conditions. Aug 26, 2017 in order to evaluate a wells productivity there are number of direct and indirect tests but dst or drill stem test is the most authentic test of them all. In order to evaluate a wells productivity there are number of direct and indirect tests but dst or drill stem test is the most authentic test of them all. Pro test has a high rate of successful tests, a key measure of performance and the major factor in reducing the cost of testing services. One of the most important stages of completing a well is discussed in this report which is the drill stem testing dst.
This seminar paper will present methods for the quantitative analysis of drill stem test. A dst is a systematic procedure for evaluating the hydrocarbon potential of a reservoir. Kos announced today that it has successfully completed the drill stem test dst of the tortue1 well, demonstrating that the tortue field is a worldclass resource and confirming key development parameters including well deliverability, reservoir connectivity. The drill stem testing tools are applied in cased hole, open hole and slim hole, the main dst tool string includes rtts packer, circulating valve, safety joint, select tester valve, omni valve, hydraulic jar, shock absorber, rd safety circulating valve, high pressure retrievable packer with bypass, ipo valve, tubing string test valve, and so on. Drill stem test pressure chart is a chart created while performing drill stem test dst. Drill stem testing is an oil and gas exploration procedure to isolate, stimulate and flow a downhole formation to determine the fluids present and the rate at which they can be produced the main objective of a dst is to evaluate the commercial viability of a zones economic potential by identifying productive capacity, pressure, permeability or extent of an oil or gas reservoir. Conduct mini dst and fluid sampling to characterize a very low permeability formation in a north sea deviated hpht well. The dst or drill stem test used in both oil and gas wells, in cased or uncased wells. We suggest the running of a drill pipe safety valve in the test string, most drilling contractors have the safety valve on the rig floor, and if not bjs dst has the valve available. Overview drill stem testing dst is a procedure to determine the potential productivity, pressure, permeability or extent of an oil or gas reservoir before the permanent. Drill stem test a drill stem test dst is a temporary completion of a wellbore that provides information on whether or not to complete the well. The three fundamental components are a retrievable mechanically set packer, a downhole valve assembly dst tools and drill pipetubing to surface. Reservoir pressure and temperature formation fluid collection establish well productivity permeability drainage area delineation.
Confirmed the very low permeability of the formation, with no fracture. The test is a valuable and cost effective test that is mainly employed in exploratory wells. Khosraw bazrafshan petroleum geology university of kurdistan hewler 1 abstract. Overview drill stem testing dst is a procedure to determine the potential productivity, pressure, permeability or extent of an oil or gas. Conclusion a drill stem test dst is a procedure for isolating and testing the pressure, permeability and productive capacity of a geological formation during the drilling of a well. Expro offers the complete well test package, utilising some of the industrys most reliable technologies. Drill stem testing follows the basic principles of mechanics, hydromechanics, common sense and practicability. After the operator determines that a formation test is to be conducted, the test tool is assembled and lowered into the wellbore. Pdf in the paper results of dst tests obtained in two wells at osobnica oil field are presented. Before any drill stem test, conduct a safety meeting of all personnel participating in the test. Aifes drill stem test dst database contains over 170,000 analyzed tests for the united states covering the period 1948 to present. Drill stem testing is an oil and gas exploration procedure to isolate, stimulate and flow a downhole formation to determine the fluids present and the rate at which they can be produced. With close links to our long established subsea product line development group, a dedicated dst engineering team guided by seasoned professionals, work together inhouse to develop and introduce innovative dst tools.
Kosmos energy announces successful completion of tortue. Deploy mdt modular formation dynamics tester with the dualpacker module to effectively isolate a large interval of the borehole for fluid sampling and to conduct a mini dst. The main objective of the test is to study the reservoir characteristics as well as. Drill stem test dst drilling operations netwas group oil. The procedures listed below may be followed by operating company personnel to improve drill stem testing safety on their rigs. Muhammad sohail khan muhammad bilal drill stem test dst. A drill stem test dst is a procedure for isolating and testing the pressure, permeability and productive capacity of a geological formation during the drilling of a well. The configuration from the drill pipe safety valve up through the test head, through the steel flow lines to the floor manifold up to the rigs flare line, is the standard layout for the surface equipment. Drill stem test dst drill stem testingdst drill stem. The main objective of a dst is to evaluate the commercial viability of a zones economic potential by identifying productive capacity, pressure, permeability or. This report discusses three main aspects of this technique, it indicates the detailed function of each component of the tool. They are run during or after the drilling of a well, but before casing installation.
After the well has been drilled and cased, the first stage of a well test is to run a dst string in conjunction with a downhole data system with the option to include tubing conveyed sampling and tubing. Formation fluid pressure from drill stem tests aapg wiki. The testing equipment is attached to the end of the drill string. A temporary well completion to gather information on the potential productivity of a formation. Pdf one of the most important stages of completing a well is discussed in this report which is the drillstem testing dst. Full bore test packers the fullbore test packer fbtp is specially designed for full bore drill stem testing dst and tubing conveyed perforating tcp operations.
Drill stem testing, dst drill stem testing provides a method of temporarily completing a well to determine the productive characteristics of a specific zone. The test is an important measurement of pressure behaviour at the drill stem and is a valuable way of obtaining information on the formation fluid and establishing whether a well has found a commercial hydrocarbon reservoir. A drill stem test dst offers the fastest and safest method of evaluating the potential of a newlydiscovered hydrocarbonbearing formation. A drill stem test dst is a procedure for isolating and testing the pressure, permeability and productive capacity of a geological formation during the drilling of a. After the well has been drilled and cased, the first stage of a well test is to run a dst string in conjunction with a downhole data system with the option to include tubing conveyed sampling. There are essentially no standard ascii dst data files formats existing that will allow the user to read and process dst data.
Every pump shutdown and startup is an opportunity to evaluate well productivity and obtain reservoir parameters. This test is a valuable and costeffective test that is mainly employed in exploratory wells. Slim hole drill stem test toolsround mandrel slip joint. Drillstem testing dst is one of the most important completion technique s. Drill stem testing injection testing well stimulation subsea wells where rotation of the work string is undesirable or prohibited. In making any interpretation, our employees will give customer the benefit of their best judgment as to the correct. The test is an important measurement of pressure behaviour at the drill stem and is a valuable way of obtaining information on the formation fluid and. During a dst drill stem test, pressure is continuously recorded against time.
During the well test, different drawdowns could be imposed via an mvd to create the required pressure transients and meet test objectives, and the artificial lift team has the expertise to obtain valuable reservoir parameters from any esp dst andor tcp test. Expro is committed to advancing technology in the field of drill stem testing dst and our investment is driven by the requirements of existing and emerging growth markets. Drill stem testing dst is one of the most important completion well testing techniques. Drill stem tests dsts are a type of bottom hole buildup test. Dst stands for drill stem test also decision support tool and 439 more what is the abbreviation for drill stem test. Analysis of drill stem test dst results at osobnica oil field, in terms of sampling of selected technology parameters article pdf available june 2017 with 988 reads how we measure reads. Minidst and sampling instead of hpht well test, north sea. Figure 2 is a dst drill stem test plot, showing the various pressures recorded during the different dst drill stem test periods point a is the initial hydrostatic pressure ihp, the pressure. Whether your goal is to determine reservoir pressure, permeability, skin, or productivity, our down hole technology delivers the right answers. Jan, 2018 conclusion a drill stem test dst is a procedure for isolating and testing the pressure, permeability and productive capacity of a geological formation during the drilling of a well. A drill stem test dstdrill stem test is a temporary completion of a wellbore that provides information on whether. Drill stem testing pro test personnel have extensive experience with open hole drill stem testing services across both conventional oil and gas well and coal bed methane wells. Each analysis is derived from the original drill stem test report,not transcribed from scout or field data. All of bjs dst s surface equipment is pressure tested regularly at the shop to 6,000 psi.
Petropedia what is drill stem test pressure chart dst. The rezconnect well testing system is the industrys first fully acoustically actuated drill stem test dst system offering a complete well testing solution for acoustic control of dst tools, with measurement and analysis of welltest data in realtime. A drill stem test dst drill stem test is a temporary completion of a wellbore that provides information on whether or not to complete the well. Drill stem test dst is the conventional method of formation testing and reservoir evaluation which obtains reservoir data under dynamic rather than static conditions. Pdf analysis of drill stem test john ansa academia. The test is an important measurement of pressure behaviour at the drill stem and is a valuable way of obtaining information on the formation fluid and establishing whether a. Crains petrophysical handbook permeability drill stem. Jan 12, 2018 drill stem test dst is the conventional method of formation testing and reservoir evaluation which obtains reservoir data under dynamic rather than static conditions. Often referred to as dst, these tests are usually conducted with a downhole shutin tool that allows the well to be opened and closed at the bottom of the hole with a surfaceactuated valve. Drill stem test dst2 zthe basic drill stem test tool consists of a packer or packers, valves or ports that may be opened and closed from the surface, and two or more pressure. The main objective of the test is to study the reservoir characteristics as well as evaluate the commercial aspects of the reservoir. The record begins as the dst drill stem test tool is lowered down the borehole and ends when the tool returns to the surface.
After the operator determines that a formation test is to be conducted, the test tool is. Jan 14, 2018 the data derived from the drill stem test dst give a computation of the formations permeability, damage ratio, productivity index, transmissibility and radius of investigation. We have vast operational experience both onshore and offshore, with more than 500 dst jobs successfully completed in more than 20 countries, worldwide. A drill stem test dst is a systematic procedure for evaluating the hydrocarbon potential of a reservoir. Drill stem test dst 2 zthe basic drill stem test tool consists of a packer or packers, valves or ports that may be opened and closed from the surface, and two or more pressure. The data derived from the drill stem test dst give a computation of the formations permeability, damage ratio, productivity index. Jan 14, 2018 for the love of physics walter lewin may 16, 2011 duration. One or more pressure gauges are customarily mounted into the dst tool and are read and interpreted after the test is completed. Halliburton improves on the technique by integrating existing technology with recent developments in dst tools and sampling technologies.