1、Designation: D4520 13Standard Practice forDetermining Water Injectivity Through the Use of On-SiteFloods1This standard is issued under the fixed designation D4520; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last re
2、vision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This practice covers a procedure for conducting on-sitecore flood tests to determine the filtration and chemicaltreatment re
3、quirements for subsurface injection of water.2, 31.2 This practice applies to water disposal, secondaryrecovery, and enhanced oil recovery projects and is applicableto injection waters with all ranges of total dissolved solidscontents.1.3 The values stated in SI units are to be regarded sepa-rately
4、as standard. The values stated in each system aremathematical conversions and may not be exact equivalents;therefore, each system shall be used independently of the other.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility
5、 of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:4D420 Guide to Site Characterization for Engineering Designand Construction Purposes (Withdrawn 2011)5
6、D653 Terminology Relating to Soil, Rock, and ContainedFluidsD1129 Terminology Relating to WaterD2434 Test Method for Permeability of Granular Soils(Constant Head)D4404 Test Method for Determination of Pore Volume andPore Volume Distribution of Soil and Rock by MercuryIntrusion Porosimetry2.2 America
7、n Petroleum Institute Standards:6API RP27 Recommended Practice for Determining Perme-ability of Porous MediaAPI RP40 Recommended Practice for Core-Analysis Pro-cedure3. Terminology3.1 Definitions:3.1.1 For definitions of terms relating to water and waterchemistry, refer to Terminology D1129. Refer t
8、o TerminologyD653 for definitions relating to soil and rock3.2 Definitions of Terms Specific to This Standard:3.2.1 filtration requirement, nthe maximum suspendedsolids size (in micrometres) allowed in an injection water tominimize formation plugging.3.2.2 test core, na sample cut from a full-core t
9、hat hasbeen recovered from the formation into which water is in-jected.3.2.3 permeability, nthe capacity of a rock (or otherporous medium) to conduct liquid or gas; permaeability ismeasured as the proportionality constant between flow velocityand hydraulic gradient.3.2.4 pore volume, nthe porous med
10、iums void-volumethat can be saturated with the transmitted fluid.3.2.5 porosity, nthe ratio (usually expressed as a percent-age) of the volume of voids of a given soil, rock mass, or otherporous medium to the total volume of the soil, rock mass, orother porous medium.3.2.6 rock-water interaction, na
11、 reaction between a po-rous rock and the injected water causing precipitation orswelling or release of fines (clays) within the rock.4. Summary of Practice4.1 This practice assumes that the injection water has beencharacterized in terms of dissolved and suspended solids1This practice is under the ju
12、risdiction of ASTM Committee D19 on Water andis the direct responsibility of Subcommittee D19.05 on Inorganic Constituents inWater.Current edition approved Jan. 1, 2013. Published February 2013. Originallyapproved in 1986. Last previous edition approved in 2008 as D4520 03(2008).DOI: 10.1520/D4520-1
13、3.2Farley, J. T., and Redline, D. G., “Evaluation of Flood Water Quality in the WestMontalvo Field,” Journal Petroleum Technology, July 1968, pp. 683687.3McCune, C. C., “On-Site Testing to Define Injection Water QualityRequirements,” Journal Petroleum Technology, January 1977, pp. 1724.4For referenc
14、ed ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.5The last approved version of this historical standard is referenced onwww
15、.astm.org.6Available from American Petroleum Institute (API), 1220 L. St., NW,Washington, DC 20005-4070, http:/www.api.org.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United State
16、s1contents (including hydrocarbons and other organics as appli-cable) by established standard practices and methods.4.2 Test core material is selected by consultation betweengeologists and engineers and prepared for the tests by standardpractices.4.3 In the on-site core flood the permeability of the
17、 test coreis monitored to detect interactions between the formation rockand the injection water. The water is filtered at various levels todetermine the filtration required (in micrometres) to minimizepermeability loss (damage) from suspended solids. Backflow-ing injection wells are simulated by rev
18、ersing the flow direc-tion through the cores.5. Significance and Use5.1 The injectivity of a water is best determined by mea-surements as near to the well as possible to minimize changesin water properties due to air contact and time. This practicedescribes how core flow tests are carried out near t
19、he well.5.2 This practice permits the differentiation of permeabilitylosses from the effects of chemical interaction of water androck and from the effects of plugging by suspended solids. Theprocedure can be utilized to estimate the chemical and filtrationrequirements for the full-scale injection pr
20、oject.5.3 Application of the test results to injection wells requiresconsideration of test core selection and geometry effects.5.4 This practice as described assumes that the water doesnot contain free oil or other immiscible hydrocarbons. Thepresence of free oil would require the method to be modif
21、ied toaccount for the effect of oil saturation in the test cores on thewater permeability.6. Sources of Rock-Water Interactions6.1 Water injected into a porous rock may interact with therock to reduce the permeability as a result of the formation ofprecipitates, clay swelling, clay dispersion, or th
22、e migration ofother fine solids.6.2 Rock-water interactions are more common in sand-stones than in carbonate rocks. However, within carbonaterocks dissolved iron in the injection water may precipitateespecially in the presence of dissolved oxygen. Alkalineprecipitates (CaCO3and Mg(OH)2) may also for
23、m in carbonaterocks.6.2.1 Dissolved hydrogen sulfide in the presence of dis-solved iron and oxygen can also be a problem in watersinjected into carbonate and sandstones resulting in precipita-tion of sulfides and hydroxides of iron.6.3 The iron and alkaline precipitates described in 6.2 canalso form
24、 from waters injected into sandstones. Swelling typeclays (montmorillonite and mixed layer clays) and dispersibleclays (kaolinite and chlorite) are potential sources of perme-ability losses due to changes in salinity or ionic content of theinjected water compared to the natural waters in the formati
25、on.In some sandstones fine mica particles have been caused tomigrate by the injection of a potassium ion deficient water.6.4 In some instances in both sandstones and carbonatessome fine particles are released to migrate as a result of watersaturating the cleaned and dried test cores.7. Apparatus7.1
26、A schematic diagram of the test apparatus is shown inFig. 1. The component parts are assembled from commerciallyavailable laboratory apparatus with the exception of the coreFIG. 1 Schematic of Test EquipmentD4520 132holders (Fig. 2). While four cores are shown in Fig. 1 thenumber used in a test is o
27、ptional. The apparatus essentiallyconsists of a filtration section and a core flood section. Thevarious components are connected with plastic or stainlesssteel flow lines with required valves and gauges as illustrated.7.2 The filtration section is assembled from four cartridgefilter holders mounted
28、two each in series. Valves are installedto permit flow through either filter pair or to bypass the filters.Pressure gauges are included for monitoring the inlet anddischarge pressure of the filters. Commercial filters are avail-able with ratings ranging as low as 0.2 m. The rated sizes usedin the on
29、-site core flood tests generally range from 0.45 to 10m. The filter holders should be provided with vents to saturatethe filters and purge air from the system.7.3 The core flood section of the apparatus consists of alaboratory constant temperature bath rated for up to 150C(302F) and of adequate capa
30、city to hold up to four coreholders (Fig. 2). Necessary valves and gauges are provided. Asshown in Fig. 1, two of the core holders (No. 1 and No. 2) areplumbed to allow the flow through the cores to be reversedwithout removing the core holders. The pressure to the coreflood section is controlled wit
31、h a regulator, and a test gauge isused to accurately monitor the test core inlet pressure. The testcore discharge pressure is atmospheric when the apparatus isassembled as shown in Fig. 1.7.3.1 Another option is to control the discharge at a pressureabove atmospheric by the addition of a regulator o
32、n each coresample discharge line. This option is recommended if theevolution of dissolved gas is anticipated from the water as itflows through the test core.7.4 An alternative to the core holders (Fig. 2) is a Hassler-type permeability cell (API RP40) which uses a rubber orplastic sleeve to form the
33、 seal around the core sample. Ahigh-pressure air (nitrogen) or liquid supply to maintain theseal would be required.7.5 The operating gauge pressure of the test apparatus isusually 700 kPa (100 psig) or less.7.6 As shown in Fig. 1, facilities may also be provided forthe addition of chemicals to the w
34、ater being tested. A chemicalsupply tank and an injection pump with pressure and flowratings corresponding to specific needs would be required.7.7 The apparatus is attached to a line carrying the waterbeing tested. Usually, the line pressure of the water source(regulated as required) satisfies the p
35、ressure requirement forflowing the water through the filters and test cores. If thesupply pressure is insufficient, a small pump capable ofdelivering about 1 L/min at 700 kPa is used.7.8 Other required apparatus are the following:7.8.1 Mechanical (non-aspirator type) vacuum pump,7.8.2 Assorted beake
36、rs (250 to 1000 mL),7.8.3 Assorted graduated cylinders (10 to 100 mL),7.8.4 Stopwatch,7.8.5 Vacuum tubing, and7.8.6 Assorted tools for assembling and disassembling theequipment as required.8. Procedure8.1 Core Selection:8.1.1 Choose proper core samples to yield the most mean-ingful test results thro
37、ugh close coordination with geologists,chemists, and engineers responsible for the water injectionproject.8.1.2 To assist in that choice include well logs, mineralogy,porosity, pore size distribution, permeability, and other coredescriptive data.8.1.3 Choose test cores to represent the zones that wi
38、llreceive the injected water. The best samples are from wholecores cut from those zones. Prepare sufficient samples torepresent the ranges of permeability, porosity, and mineralogyof the injected zones. Consider the presence of natural frac-tures.8.1.4 Select the number and properties of the cores f
39、or aparticular test according to one of the following options:8.1.4.1 Use cores having similar properties (porosity,permeability, mineralogy, etc.). Average the results.8.1.4.2 Use a set of cores with one of these propertiesdifferent in each core to test the effect of this property on thetest result
40、s.8.1.5 If cores from the flooded zone are not available,choose another zone with similar properties as the next bestalternative sample source. As a third choice use synthetic corematerial (alumina, silica, porous glass, etc.).8.2 Core Sample Preparation:FIG. 2 Schematic Diagram of Sample HolderD452
41、0 1338.2.1 Follow the recommended procedures for corehandling, preservation, cutting, and cleaning described in APIRP40. (This extensive document describes various proceduresand options that the investigator may choose depending on thetype and condition of the cores being tested.) Related ASTMstanda
42、rds are Guide D420, Test Method D2434, and TestMethod D4404.8.2.2 The preferred sample dimensions for the core floodtest are 19 mm (0.75 in.) to 38 mm (1.5 in.) outside diameterwith a minimum length to diameter ratio of 1:0.8.2.3 Carry out the following procedure for each coresample in the set to be
43、 tested:8.2.3.1 Cut the core sample parallel to the formation bed-ding plane and then clean by solvent-extraction to removeresidual hydrocarbons and water from the pore space. Dry thesample and determine the porosity according to the recom-mended procedures in API RP40.8.2.3.2 Use the air permeabili
44、ty of the core sample as aguide for choosing representative samples of the formationbeing tested. The procedure for measuring air permeabilities isdescribed in API RP27.8.2.3.3 Seal the core sample with an epoxy resin or othersuitable sealant in a metal (stainless steel, aluminum, brass)tube having
45、an inside diameter about 6.4 mm (0.25 in.) largerthan the outside diameter of the sample.8.2.3.4 Machine the ends of the core sample and metal tubeflat and perpendicular to the tube axis. Generally a stream ofcompressed air on the core ends during machining will preventthe intrusion of fines into th
46、e rock pores.8.2.3.5 Mount the metal tube (containing the core sample)in a holder designed to allow water to be flowed through thesample. An example of such a sample holder is shownschematically in Fig. 2.8.3 Vacuum Saturation of Test Cores :8.3.1 Install a 10-m rated cartridge in filter No. 1 and a
47、0.45-m cartridge in filter No. 2. Close valves to and fromfilters No. 3 and No. 4, the filter bypass valve, and valves to allcore sample holders.8.3.2 Open the valve-to-waste upstream and downstream ofthe regulator and the valves to and from filters No. 1 and No.2. Start water flow through the filte
48、rs to waste.8.3.3 Close the valve-to-waste upstream of the pressureregulator. Set the regulator at about 120 kPa (17 psi) more thanthe pressure planned for the test. After about 2 min, close thevalve-to-waste downstream of the regulator.8.3.4 Mount from one to four sample cores in the holders(lines
49、should not contain water) and attach the core sampleholders to the valves.8.3.5 Open the valves on the effluent ends of the coreholders and attach the vacuum pump (with vacuum tubing) tothe lines from the effluent end of the core holders. Run thevacuum pump for at least 1 h noting the vacuum gauge on thepump to check for leaks.8.3.6 After at least 1 h, close the valves from the effluentends of core holders and shut off and disconnect the vacuumpump and tubing.8.3.7 Open the valve-to-waste downstream of the regulatorto check water flow and then close the valve. Open
