Reservoir surveillance engineer with master degree and 9 yrs. This test overcomes the limitation of the isochronal test, which requires long shutin times to reach the average reservoir pressure. Our third course in our online education series is test design. Deliverability test an overview sciencedirect topics. Gas deliverability analyses require gas properties in addition to pressure and rate data. A test design is developed to portray the test effort, in order to give project and test personnel a mental framework on the boundary and scope of the test program. Validity of isochronal and modified isochronal testing of gas. Software test design techniques static and dynamic testing.
Introduction to the software, input data, functionalities and limitations. After a stabilized sibhp is achieved, the well is produced in the same sequence as a rateafterrate test, except that at the. The program also uses backpressure test data and current flow data to predict flow at a given suction pressure for use in compressor design. In software engineering, test design is the activity of deriving and specifying test cases from test conditions to test software definition. Interference test pulse test producing well measure pressure in another shutin well away from the producer communication test gas well test back pressure, isochronal test, modified isochronal test well productivity, aofp, non darcian skin. The fracture treatment design and analysis data for the selected. Standard for software component testing from bcs sigist. Conflict between design engineers and test engineers. The shutin periods should equal or exceed the length of the flow periods. A modified isochronal well testing simulation model is developed based on the.
A simulation method for modified isochronal well testing to. For the modified isochronal test, the analysis presented in the board manual is incomplete. Technologist and evangelist peter varhol and gerie owens, a test architect and certified scrummaster, discuss their starwest presentation, what aircrews can teach testers about testing. Examples to some of the techniques you can find in. The same procedure typically is repeated four times. Oil deliverability analyses require only pressure and rate data. Sep 17, 2015 a test design is developed to portray the test effort, in order to give project and test personnel a mental framework on the boundary and scope of the test program. Pepta is a pressure transient analysis software for interpretation of pressure build up, draw downs and back pressure tests. Test design is complex document describing the testing process.
Guidelines for conducting production tests energysea. This course provides an extensive and practical knowledge in well test design and analysis aimed at evaluating well productivity and reservoir parameters in the best technical and economical way. Well deliverability is calculated using a modified form of the evingermuskat pseudopressure originally proposed for solution gas drive oil wells. Software test design techniques static and dynamic testing the importance of software test techniques. Software testing is a process carried out to check and confirm the delivery potential of the software.
The duration of this complex deliverability test could be shortened with the modified isochronal test with an increasing step rate test. This test is used to generate a stabilized gas deliverability curve without actually flowing the well for the time required to achieve stabilized conditions pseudosteady state. Conclusions 1 in this paper, a productivity model for a tight gas reservoir is developed. Combining the simplified analysis and the more rigorous laminar inertial turbulent lit analysis of isochronal and modified isochronal tests, it has been shown that these tests are valid, within engineering accuracy, for all values of the inverse sloe, n. It is called isochronal because the flow periods are of the same length. Design for testability design for testability dft dft techniques are design efforts specifically employed to ensure that a device in testable. A multirate test designed as a series of drawdown and buildup sequences at different drawdown flow rates, with each drawdown and buildup of the same. Test conditions can be stated for any part of a component or system that could be verified.
Back pressure, isochronal test, modified isochronal test well productivity, aofp, non darcian skin. To further economize backpressure testing, katz et al. Deriving test cases directly from a requirement specification or black box test design technique. An earlier pbu analysis will help to improve the design of the deliverability test. Internationally representative well test software includes saphir kappa.
Gas well absolute open flow aof tests publications. A type of deliverability test conducted in gas wells to generate a stabilized gas deliverability curve. Mar 10, 2015 software test design techniques static and dynamic testing the importance of software test techniques. The equation which relates gas flow rate, average pressure within drainage area and stabilized sand face flowing pressure. In that methodology, the tests are written before anything else. Likewise, the pressure build up periods are also of equal duration, but not necessarily the same as the flow periods. Identification of well problems using well testing in the petroleum industry, a well test is the execution of a set of planned data acquisition activities.
In an isochronal test, the well flows at a constant rate and then is shut in, allowing. Other considerations when designing a production flow test. Software test design techniques, static and dynamic test design techniques, black box techniques, equivalence classes, boundary value analysis, decision table testing, state transition testing and. Sep 12, 2014 if too short, the results for this deliverability test on these types of reservoirs could be misleading. How to design a deliverability test combined with chinese geological characteristics. It is a comprehensive, stateoftheart, easy to use well test design and analysis tool. Advanced well test analysis certification ifp training. Modified isochronal test mit design and analysis for annual campaigns for current producing wells using saphir software kappa package. Instead of seeing through walls, you can see the inner structure of programs, the bugs lying inside, and how to expose them.
This type of test is especially useful for lowpermeability reservoirs. Both analytical and numerical methods will be applied. In this procedure, a set of predecided inputs are fed into the software and the output produced is measured against the expected results. Apr 10, 2016 software test design techniques, static and dynamic test design techniques, black box techniques, equivalence classes, boundary value analysis, decision table testing, state transition testing and. The analysis of a modified isochronal test using the simplified method is shown below. Energy technical resources for oil and gas professionals. They talk about how testers can apply airline safety practices to their teams delivery of highquality applications through complementary expertise, collaboration, and. The well does not build up to the average reservoir pressure during shutin. Involved in design of rups, louts and wo programs for safe well interventions. Its guibased data editor facilitates quick and easy editing of these and other data in desired. I want to design an optimum time to shut in an existing gas well. Test production from the well will most likely need to be routed into the test separator, and then the oil will be sent to a stock tank so it. Testing of dry gas, wet gas and gas condensate reservoirs.
A simulation method for modified isochronal well testing. A modified isochronal test in which the flow periods are of equal duration. Course rengadvwelltest advanced well test analysis. The results of the analysis are used to determine the minimum amount of material, better than the subgrade, required to prevent. The program also uses backpressure test data and current flow data to predict flow at a given suction pressure. If too short, the results for this deliverability test on these types of reservoirs could be misleading. It is the operators responsibility to design and conduct individual isochronal well tests so that. Deriving test cases directly from the structure of a component or system. Modified isochronal the modified isochronal test is used on tight reservoirs where it takes a long time for the shut in pressure to stabilise. In an isochronal test, the well flows at a constant rate and then is shut in, allowing the pressure to build up to the average reservoir pressure. Pepta has a simple but effective graphical user interface with interactive diagnostic plot of pressure, semilog derivative, and primary pressure derivative. The purpose of performing an isochronal test is to determine the rate dependent skin. Reservoir surveillance engineer with master degree and 9. Estimating the stabilized deliverability of a gas well.
Applied pressure transient analysis with real well testing. Basic concepts in well testing for reservoir description patrick corbett hamidreza hamdi. A test to verify the stabilized flow capability of every gas well must be carried out during the. As the duration of the shutin periods increases, the accuracy of the modified isochronal test also increases.
Basic concepts in well testing for reservoir description. A type of deliverability test conducted in gas wells. Gas well testing flow after flow test, isochronal test and modified isochronal test advanced well test analysis. An isochronal test is a series of drawdowns and buildups.
The analysis of modified isochronal tests to predict the stabilized deliverability of gas wells without using stabilized flow data. Estimating the stabilized deliverability of a gas well using the rawlins and schellhardt method. Distance applied pressure transient analysis with real. The approved test method is the fourpoint isochronal or modified isochronal method section. Isochronal and modified isochronal tests are developed to shorten. The goal is to capture the specification with a set of small positive and negative unit tests. Testdriven design, a methodology for lowdefect software. The modified triaxial design method requires the use of the subgrade andor base texas triaxial class as derived from laboratory test results. The analysis module in pta allows you to analyze deliverability data from flow after flow tests, isochronal tests, and modified isochronal tests to obtain an aof absolute open flow potential. Sep 19, 2016 the modified isochronal test is conducted like an isochronal test, except the shutin periods are of equal duration. Gas compressor design program journal article osti. The dawson bay watt mountain slave point interlude. The theoretical basis for both isochronal and modifiedisochronal tests was initially provided. Estimating the stabilized deliverability of a gas well using.
Theoretical basis of isochronal and modified isochronal. Test production from the well will most likely need to be routed into the test separator, and then the oil. This indicates that the simulation method for modified isochronal well testing can be used reliably to determine shale gas well productivity in the absence of field testing. Although there are a number of terms to understand in software development, test planning and test design are two critical assets that must be fully utilized. Software test architecture design focusing on test viewpoints. Pdf calculation of horizontal well productivity in low. For the modified isochronal test, p ws must be used instead of p r because the duration of each shutin period is too short to reach static conditions. As a result, the modified isochronal test is less accurate than the isochronal test. Determination of gas well deliverability of vertically. Again, a final stabilized flow point usually is obtained at the end of the test but is not required for analyzing the test data. A modified isochronal testin which drawdown and buildup periods are of equal durationmay also be used.
Read more about our course rengadvwelltest advanced well test analysis. Deriving test cases based on testers experience on similar systems or testers. The purpose of the test is to determine well deliverability, and this type of test is most commonly done in gas wells. Pdf prepost frac test data analysis for hydraulically. Software test design techniques static and dynamic. The compress program written in microsoft quickbasic 4. How to determine the minimum shut in time for gas well testing. This paper gives an accurate method for modeling the deliverability of gas condensate wells. This is a simple method which rquires only data from a modified isochronal test to develop a performanceprediction for the well withouta priori estimatesof reservoirproperties. Participants will be introduced to a systematic approach to well test analysis and will apply it using modern well test analysis software. Isochronal modified tests isochronal tests and modified isochronal tests provide more accurate deliverabilities than those provided by a rateafterrate test and also permit evaluation of ratedependent skin. Then some code is written and run on the unit tests. In view of the long pressure stabilization time of low permeability gas reservoirs, the traditional backpressure test was modified based on the idea of isochronal test in order to evaluate gas.
Upon completion of the course, participants will be able to. Full text of simulating an isochronal scheduled inspection system for the p3 orion see other formats naval postgraduate school monterey, california thesis simulating an isochronal scheduled inspection system for the p3 orion by jeffrey a. The flow and shutin periods are of the same length, except the final flow period which is extended similar to the isochronal test. Good testing requires application of many test techniques. This is based on flow and shutin periods of same duration. Pumping rates vary for each drawdown, while subsequent buildups continue until the well reaches its original shutin pressure. Participants will look at a few techniques more closely than the rest but do not become skilled practitioners of any single technique. As a result, the analysis techniques are more complex than for flowafterflow, isochronal, or modified isochronal test data. The course emphasizes the practical application of well test theory to the solution of real well testing problems from design through interpretation for oil, gas and water injection wells. Mar 23, 2015 modified isochronal the modified isochronal test is used on tight reservoirs where it takes a long time for the shut in pressure to stabilise. In the modified isochronal test, the shutin periods are of equal duration, as are the flowing periods. This test, known as the modified isochronal test, is schematically shown in fig. The data is plotted on a loglog plot of d p 2 versus q st where d p 2 is defined as. Oil and gas well tests can be easily analysed by means of numerous analysis methods in pepta.
It describes a list of inputs for given software that will provide a set of expected outputs. Each technique is better at exposing some types of problems and weaker for others. How was your interview experience at ongc through gate. Practical well test design to evaluate hydraulic fractures in low permeability wells. A test condition is a statement about the test object. Validity of isochronal and modified isochronal testing of. Pressure buildup pbu and transient tests design and analysis using saphir software for both appraisal and development wells. Prepost frac test data analysis for hydraulically fractured vertical tight gas wellfield case study. However, the method provides a means to estimate deliverability of slowinstabilizing wells and consists of running a minimum of three modified isochronal tests with each test composed of a minimum of three flow rates. Following are the typical design techniques in software engineering.
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