ASTM_E_1675_-_04_2012.pdf

Designation:E167504(Reapproved 2012)Standard Practice forSampling Two-Phase Geothermal Fluid for Purposes ofChemical Analysis1This standard is issued under the fixed designation E1675;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 The purpose of this practice is to obtain representativesamples of liquid and steam as they exist in a pipelinetransporting two-phase geothermal fluids.1.1.1 The liquid and steam samples are collected andproperly preserved for subsequent chemical analysis in thefield or an off-site analytical laboratory.1.1.2 The chemical composition data generated from theanalysis of liquid and steam samples may be used for manyapplications important to geothermal energy exploration,development,and the long-term managed exploitation ofgeothermal resources.These applications include,but are notlimited to,resource evaluations such as determining reservoirtemperature and the origin of reservoir fluids,compatibility ofproduced fluids with production,power generation and rein-jection hardware exposed to the fluids(corrosivity and scaledeposition potential),long-term reservoir monitoring duringfield exploitation,and environmental impact evaluations in-cluding emissions testing.1.1.2.1 To fully utilize the chemical composition data in theapplications stated in 1.1.2,specific physical data related to thetwo-phase discharge,wellbore,and geothermal reservoir maybe required.Mathematical reconstruction of the fluid chemistry(liquid and steam)to reservoir conditions is a primary require-ment in many applications.At a minimum,this requires preciseknowledge of the total fluid enthalpy and pressure or tempera-ture at the sample point.Fluid reconstruction and computationsto conditions different from the sample collection point arebeyond the scope of this practice.1.2 This practice is limited to the collection of samples fromtwo-phase flow streams at pressures greater than 70 kPa gauge(10 psig)and having a volumetric vapor fraction of at least20%.This practice is not applicable to single-phase flowstreams such as pumped liquid discharges at pressures abovethe flash point or superheated steam flows.Refer to Specifica-tion E947 for sampling single-phase geothermal fluids.1.3 The sampling of geothermal fluid two-phase flowstreams(liquid and steam)requires specialized samplingequipment and proper orientation of sample ports with respectto the two-phase flow line.This practice is applicable to wellsnot equipped with individual production separators.1.4 In many cases,these techniques are the only possibleway to obtain representative steam and liquid samples fromindividual producing geothermal wells.The sampling prob-lems that exist include the following:1.4.1 Unstable production flow rates that have a largedegree of surging,1.4.2 Unknown percentage of total flow that is flashed tosteam or is continuously flashing through the productionsystem,1.4.3 Mineral deposition during and after flashing of theproduced fluid in wellbores,production piping,and samplingtrains,1.4.4 Stratification of flow inside the pipeline and unusualflow regimes at the sampling ports,and1.4.5 Insufficient flash fraction to obtain a steam sample.1.5 This practice covers the sample locations,specializedsampling equipment,and procedures needed to obtain repre-sentative liquid and steam samples for chemical analysis.1.6 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility 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.For specific hazardstatements,see Section 7.2.Referenced Documents2.1 ASTM Standards:2E947 Specification for Sampling Single-Phase GeothermalLiquid or Steam for Purposes of Chemical Analysis2.2 Other Document:ASME Code Section VIII,Division 1(1986),Pressure VesselDesign,Fabrication and Certification31This practice is under the jurisdiction of ASTM Committee E44 on Solar,Geothermal and OtherAlternative Energy Sources and is the direct responsibility ofSubcommittee E44.15 on Geothermal Field Development,Utilization and Materials.Current edition approved Dec.1,2012.Published December 2012.Originallyapproved in 1995.Last previous edition approved in 2004 as E1675 041.DOI:10.1520/E1675-04R12.2Annual Book of ASTM Standards,Vol 12.02.3Available fromAmerican Society of Mechanical Engineers 345 E.47th St.NewYork,NY 10017.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.Summary of Practice3.1 Samples are collected from a pipeline carrying two-phase geothermal fluids by using a sampling separator thatseparates liquid and steam phases through centrifugal force.Af