Installation of the spidr system for a dfit test is shown below. The term onetoone function must not be confused with onetoone correspondence that refers to bijective. Well testing techniques downhole fluid sampling earth tidal analysis flow test. Theory and analysis of injectivity tests on horizontal. Step rate injectivity test step rate testing determines the maximum wellhead injection pressure and rate to optimize potential zonal injection. Introduction an injectivity test is one of several well tests typically preformed on geothermal production and injection wells upon completion of drilling operations. Disposal wells and water flood programs use our high accuracy, high resolution equipment to ensure data quality is maintained. An increase in pore pressure through injection will decrease the matrix stress. The knowledge of reservoir properties and near wellbore conditions in injection wells is as important as in. Planning, executing, and reporting pressure transient tests revised june 3, 1998 i. Oil well testing handbook is a valuable addition to any reservoir engineers library, containing the basics of well testing methods as well as all of the latest developments in the field. Dfit test, prefrac, injection falloff, data frac or mini frac has become the dominate pressure transient test for halliburton and the spidr system in the domestic usa marketplace. The number of barrels per day of gross liquid pumped into an injection well per psi pressure differential between the mean injection pressure and the mean.
Also, the company drilled a new water disposal well, the bn2w, on the flanks of the field, which was placed into operation following the injectivity test. The availability of adequate injectivity index data is essential in the planning stage of a fluidinjection project in order to ascertain whether individual well injection volumes, as indicated by reservoir analysis studies, can be handled at economically feasible injection pressures. At the same time, modelling fracturing in geothermal reservoirs using rock. In compliance with european union eu legislation for visitors from the eu, schlumberger requests your permission to place cookies on your computer to both. The hall plot analysis of a water injection test affected. In other words, every element of the functions codomain is the image of at most one element of its domain. Most proofs i have seen use a modified newtons method to test for injectivity on a sufficiently small neighborhood by means of approximating zeros. Geologic and stratigraphic settings of aluto langano geothermal field the aluto langano geothermal field is located in the lakes district, ethiopian main rift. Transient pressure well test analysis of fractured geothermal. Exception testing is essential to missioncritical code, and dead code stripping is an important byproduct of the process. Waterflood calculations, reports and graphics are presented by layer, zone, reservoir and project summaries.
The pressure charts from the treatment, including both accurate injection rates and recorded injection pressures, can be analyzed using transient pressure analysis to determine when or if the wellbore damage was removed by the treatment. A drawdown test is one in which the rate is held approximately constant while the well pressure is measured. A linear and easytocheck sufficient condition for injectivity of a trivariate bspline parameterization is proposed. The purpose of this oneday course is to offer a complete coverage the various injection tests conducted in the industry. To be able to interpret the results of well test analysis 4. At least injector wells were dropped from the field development plan because of uncertainties about the tar mat sealing were redefined. This article describes a comprehensive, longterm injectivity test whose objective was to characterize reservoir sweep patterns so the optimum number and location of injectors could be determined. Well test analysis is a critical tool to understand well and reservoir performance. A procedure conducted to establish the rate and pressure at which fluids can be pumped into the treatment target without fracturing the formation. Analysis of temperature and reservoir properties, case. Calculating the injectivity index ii is the most common way of analysing performance of injection wells. Injectivity indicestheir prediction and determination onepetro. Best practices for step rate testing 1 the well should be shut in for long enough to let bottomhole pressures and formation pressures equalize 2 lower permeability reservoirs will require longer time steps 3 begin at a very low rate 0. The pilot injectivity tests ultimately proved to be successful, with dynamic data that included pressure transient analysis removed several faults from the geological model.
Injection well testing and the associated analysis are essentially simple, as long as the mobility ratio between the injected fluid and the reservoir fluid is unity. In the early 1960s injectivity falloff tests and the hall plots were used to evaluate the injectivity efficiency of water disposal and injectors. The transient behavior pressure falloff of these wells cannot be matched using existing well test analysis methods. Reliability key to longterm injectivity test schlumberger. The hall plot analysis of a water injection test affected by. Transient pressure analysis of geothermal wells fractured. Pdf fracturing during injectivity testing can take place in geothermal. New steprate test analysis for fracture evaluation onepetro. Alberta energy regulator frequently asked questions directive 065. Planning, executing, and reporting pressure transient tests epa.
Geologists, drilling engineers, production engineers and reservoir engineers with 15 years experience. Issue information about the injection, confining, and other zones penetrated by injection wells is needed in order to assess the capacity of geological reservoirs to accept and contain injected. The injectivity test and the falloff tests are used to estimate the reservoir properties of injection wells in waterflood and tertiary recovery projects. The injectivity test and the falloff tests are used to estimate the reservoir properties of. Injection at gradients above the fracture gradient will greatly increase the injectivity of wells as determined by a fracture sensitivity parameter which is determined from steprate data.
Dynamic underbalance perforating system helps exceed. A comprehensive system of wizards is designed to guide the user through the appropriate steps to ensure data is entered properly and that a reliable analysis is obtained. Region 5 may require a more complete analysis to determine the. Fracturing during injectivity testing can take place in geothermal wells when the reservoir has a low permeability or when the well has skin damage. Transient pressure well test analysis of fractured. A software test case is an entity for lack of a better word which has a pass or a fail result nothing else. Freescale semiconductor techniques and tools for software analysis, rev. Because conventional gulf coast and offshore shelf gulf. Realistic rock properties were fed into span rock stressedrock perforating analysis software. Water injectivity tests on multilayered oil reservoirs. A variablerate and longterm water injection test, that was.
A completion test will include a waterloss survey, an injectivity test, and a pressure falloff test. Pressure transient data can be obtained during the pressure falloff test. A steprate injectivity test is normally used to estimate fracture pressure in an injection. Section 2 presents interval analysis that will be used to check the injectivity. Searched for injectivity test in term name 1 results found i. This chapter presents pressure analysis techniques in injection wells. A shape optimization method to obtain an optimal parameterization of a computational domain. The injectivity test will provide the well with an injectivity index rating, which is usually a reliable indicator of well performance. Most stimulation treatments and remedial repairs, such as squeeze cementing, are performed following an injection test to help determine the key treatment parameters and operating limits.
Not only are evergreen subjects, such as layered reservoirs, naturally fractured reservoirs, and wellbore effects, covered in depth, but newer developments, such as well testing for horizontal wells, are. The dfit test has become the dominate pressure transient test for spidr for. When is an approval required for an injectivity test. Injectivity index article about injectivity index by the. Production testing a procedure conducted to establish the rate and pressure at which fluids can be pumped into the treatment target without fracturing the formation. Most well tests consist of changing the rate, and observing the change in pressure caused by this change in rate. In an injectivity test a single phase water is injected continuously for a certain period of time in an oil saturated zone followed by a falloff period.
A short video to present well test analysis, also known as pressure transient analysis, and why we test oil and gas wells from exploration to production. Diagnostic fracture injection testing dfit the diagnostic fracture injection test dfit a. Review of well injection tests well test horizontal well. To understand the fundamental principles of well testing 2. Injectivity test article about injectivity test by the free. An injectivity index can be calculated for the well both before and after the hfacid stage. In the early 1960s injectivity falloff tests and the hall plots were used to evaluate the injectivity.
Test planning and analysis software geological data optimum frac design goffer software. Planning, executing, and reporting pressure transient tests. Citeseerx in the hellisheidi geothermal system, sw. Unlike any other oil and gas surveillance activity, a pressure transient test provides information about well and reservoir performance permeabilitythickness kh and skin s, hydraulic connectivity over large volume and average reservoir pressure. A step rate injectivity test is normally used to estimate the transition from matrix or pseudomatrix a fracture may already be present but the bulk of the flow is radial flow to fracturedominated injection, according to a change in slope of a plot of pressure versus rate. Injectivity testing is a pressure transient test during injection into a well. Additionally, pure system software was run to determine the optimal dynamic underbalance pressure level that would ensure effective cleanup of the perforation tunnels for better injectivity. The evolution of an injectivity test and the responsive variations in reservoir properties may be ascertained by the steadystate hallplot analysis. Waterflood performance calculations application this ventex web application predicts waterflood performance for oil recovery, using craig geffen morse method.
Thus the efficiency of injectivity may be evaluated by such analysis method, in a continuous manner. Highlights different parameterizations of a computational domain have different impacts on the simulation results and efficiency in 3d isogeometric analysis. It is the responsibility of the permittee to develop a testing procedure which will generate. Section 4 presents an algorithm able to test a given function for injectivity. Injectivity test article about injectivity test by the. Postacidizing well test analysis demonstrated that the acid stimulation successfully improved overall well characteristics. Request pdf transient pressure analysis of geothermal wells fractured during well testing fracturing during injectivity testing can take place in geothermal wells when the reservoir has low. A minifrac test is an injectionfalloff diagnostic test performed without proppant. The purpose of this test is to identify injection interval or wellbore problems and injection interval characteristics. Injectivity analysis provides additional formation data which is useful for fracture designs, formation evaluation and optimizing water injection rates. A standard test refers to the simplest form of transient test which assumes the analysis is linear.
Resources applications for oil and gas reservoirs updated april 2014. The calculation can be made from only the most basic data. The transient behavior pressure falloff of these wells cant be matched using existing well test analysis methods. Guidance specific to the pressure falloff test is provided in attachment 1.
This well was required prior to recompleting the existing water disposal well. The purpose of the injectivity test is to get an indication of the total permeability of the well. Saphir offers a comprehensive builtin analytical catalog combining well, reservoir and boundary models, complemented by external models. Matrix will be held less in compression and more in tension. Fracturing during injectivity testing can take place in geothermal wells when the reservoir has low permeability or when the well has significant skin damage. Though singlephase flow of a slightly compressible fluid analysis methods are well documented in literature, transient twophase solutions and analysis techniques need further development. In mathematics, an injective function also known as injection, or onetoone function is a function that maps distinct elements of its domain to distinct elements of its codomain. Apr 16, 2006 one software testing concept that beginning software test engineers often dont fully understand is the difference between testing and analysis.
Optimal analysisaware parameterization of computational. Influence of inflow or outflow on the wellbore pressure. The test consisted of an injecting pts survey, an injectivity test, and a pressure falloff test. A numerical grid can be used for geometries beyond the scope of analytical models. Analysis of temperature and reservoir properties, case study. Mar 27, 2016 well injection tests have been used in the oil industry for various applications. A completion test at awi 87 was conducted 40 days after drilling completion, before the stimulation. Pressure transient analysis of an injectionfalloff test.
Guidance specific to the injectivity test is provided in attachment 4. Halliburton also has the ability to analyze the dfit data set via our analysis software if the client needs a primary or backup analysis to his own. The interpretation software packages have been used for the preparation of. To perform a well test successfully one must be able to measure the time, the rate, the pressure, and control the rate. Jan 14, 2014 a short video to present well test analysis, also known as pressure transient analysis, and why we test oil and gas wells from exploration to production. Initial analysis of injection pts data provided information about the location of the permeable zones and the amount of liquid accepted by each zone. Theory and analysis of injectivity tests on horizontal wells article in spe journal 82.