GAS NETWORK LEAK SURVEY EFFECTIVENESS IMPROVEMENT WITH INNOVATIVE MANAGEMENT TOOLS AND FIELD EQUIPMENT A GLOBAL APPROACH TO IMPROVE LEAK SURVEY OUTPUT

Transcription

1 GAS NETWORK LEAK SURVEY EFFECTIVENESS IMPROVEMENT WITH INNOVATIVE MANAGEMENT TOOLS AND FIELD EQUIPMENT A GLOBAL APPROACH TO IMPROVE LEAK SURVEY OUTPUT Backgrund Gas distributin netwrk peratin is ne f Gaz de France cre business. Mains Gaz de France perates (and the crrespnding services) were laid at different time perids with different techniques, frm grey irn t HDPE. During the nineties, Gaz de France started t expand its business area and frm a 100% French setting up turned t a wrldwide netwrk peratin business, having t cpe with different states f the art and varius netwrk states. Maintenance is a critical issue with cnsequences n safety and effectiveness f the energy supply fr all the clients, frm dmestic t industrial premises. Scheduled leak survey is a pwerful tl netwrk peratrs wn t knw the state f their netwrks and perfrm the needed crrective peratins, frm emergency repair t frecast replacement, t ensure the best safety level fr peple and the envirnment clse t the netwrk and t keep a high energy supply quality by maintaining the netwrk in a gd peratin state. One simple apprach fr netwrk leak survey is t submit all the netwrk t a cmmn same survey prcedure with the same survey frequency : this apprach allws fr very simple survey management but is nt always fitted t the varius states f netwrk parts, especially if the netwrk is cmpsed with very distinct technlgies, frm varius time perids and lcated within very changing envirnmental cntexts. Anther apprach is t define mre detailed maintenance guidelines, based n experience feedback as well as risk analysis issues, in rder t set different netwrk survey pririty levels with assciated survey frequencies. Cntrary t the first apprach, this is mre cmplex t manage but allws fr imprving the survey effectiveness because leak survey is fitted t each netwrk sectin characteristics : we can give as an example ne pssible rganisatin where sme sectins culd be surveyed every tw years whereas sme thers wuld be surveyed every three mnths. With gas market penings, Authrities defined lcal r natinal guidelines in rder t put netwrk peratrs under harmnised cnditins. One imprtant demand is the need fr traceability f the leak survey peratins : netwrk peratrs have t be able t reprt any part f survey peratin. This need fr traceability is ne f the needs which appeared with market penings. Eventually, urban envirnment, which cncentrates the highest netwrk density, is cntinuusly changing and frces gas cmpanies t adjust netwrk survey techniques and prcedures. Leakage surces and pints f surface detectin mved frm the street up t the sides with bth main reliability imprvement and tighter rad surfaces. On anther hand, urban areas get mre and mre prtected fr the pedestrian safety, envirnment prtectin and the increase f life quality. Bth trends intrduce strng demands fr the imprvement and the ptimisatin f leak survey prcedures and the effectiveness f the survey materials, which culd end up t the use f new types f equipment, alng with traditinal nes : this culd be anther increasing factr fr the leak survey management cmplexity. Given the abve mentined cntext changes and cnsidering the cntinuus expansin f gas distributin netwrk t answer the increasing natural gas demand, the management f leak survey peratin becmes mre and mre cmplex when gas cmpanies wish t run an ptimised leak

2 survey plicy in rder t fit their survey prcedure t netwrk characteristics. Then, leak survey management becmes a key issue and requires adapted data analysis tls and data bases t be implemented, in rder t allw the perating staffs fr keeping n perfrming their day t day duty with a always high quality and safety level. The apprach On ne hand the evlutins f the cntext created the need fr a new generatin f ptimised and better fitted t envirnmental cntext survey tls, n the ther hand ne result f these develpment as well as thse f the adjusted leak survey prcedures bring a higher cmplexity fr the survey management and this tends t create the need fr leak survey management tls, allwing netwrk peratin teams fr rganising and fllwing the whle leak survey prcess n their netwrks. These develpments have t be carried ut keeping in mind sme basic needs : T achieve the best safety and energy supply quality; T ensure the Cmplete traceability f the leak survey fr the imprvement f the prcess quality and t fit t Authrity guidelines: this leads t review all the data management prcess; Imprve the management tls in rder t allw fr cntinuusly adjusting the survey methds t the needs f the netwrk, increasing the safety level and cntrlling peratin csts; Better fcused leak survey equipment in rder t fit t tday s leak characteristics; Give a mre accurate picture f the netwrk cnditin and supply critical data fr maintenance peratins thrugh leak survey feedback. Met pmaak: psmmingstekens en nummering Gaz de France R & D divisin wrks n tw different areas t address this situatin : Management tls t fit leak survey peratins t the netwrk needs, in rder t imprve the effectiveness f the leak survey : this is dne n ne hand by analysing n a regular basis the feedback f the leak survey prcess as it is perfrmed n field and n the ther the R&D Divisin develped better fitted leak survey management tl in rder t be able t frecast, rganise and fllw the leak survey prcess while ensuring the cmplete traceability f the whle prcess: the way leak survey is managed is fed by the leak survey carrying ut feedback; A new generatin f leak survey equipment bringing traceability and data prcessing tls like GPS and nbard sftware, better fitted t mdern urban envirnment as well as the changing leak characteristics.

3 Develpments : Management tls The management tl (r sftware) PISte RSF fr leak survey has t be cmpletely fitted t the prcedures which are used within Gaz de France fr this area f peratin. Therefre, its functinalities and utilisatin prcedures entirely fllw the way peratrs define the leak survey management. This tl psitin within the leak survey prcess is intermediate between the netwrk data base (distributin netwrk G.I.S. as we will see further n) and the leak equipment nbard prcessing sftware. Main characteristics f this sftware are the fllwing : The management and frecast f the needed leak survey peratins; The fllw up f the perfrmed peratins, the prgress f the survey schedule and the crrective maintenance peratins, nce leaks have been detected; The analysis f leak survey carrying ut feedback in rder t keep n imprving leak survey management guidelines. Tw data inputs are necessary fr the leak survey management sftware : The netwrk data frm the Gaz de France distributin netwrk G.I.S.: this G.I.S. includes all netwrk characteristics, frm the gegraphic psitin f each part f the netwrk t the material f the pipe r the year the pipe was laid. This G.I.S. has t be able as well t hst specific leak survey parameters such as fr example the survey categry (pririty level), the survey frequency r the reference f the rute and the methd which is used fr surveying it ; The definitin f the maintenance rules f Gaz de France which include the leak survey : these rules have t be fllwed by the peratinal teams when they set up the management and the frecast f the leak survey. They are the prcedures t be adapted t the field cnditins and the capability f the teams each peratinal unit wns. Once bth inputs are available, the leak survey management prcess can be initiated.

4 Leak survey management Leak survey management prcess is a cmplete data analysis, prcessing and preparatin string. It can be cnsidered as a kind f prductin line, frm the G.I.S. data, ging thrugh several prcesses up t leak survey equipment data prcessing architecture and back t the G.I.S. nce surveys are cmpleted fr the feedback analysis and the pssible imprvements. The first step f the prcess is t extract all the data which will allw the peratr fr defining the leak survey management : it depends n the maintenance guidelines and it can be fr example the material f the netwrk (HDPE, steel, ), the year f installatin and bviusly the date f the last survey. The fllwing step is t apply the maintenance guidelines t the grup f netwrk cncerned in rder t set the pririty level f the survey fr each part f the netwrk and the crrespnding survey frequency. Fllwing this first step, the secnd ne will allw fr chsing the type f survey which will be used fr each netwrk part : walking survey, vehicle survey r any ther mean fr surveying. As the picture shws, bth prcesses result is t create different grups f netwrk parts which will have the same leak survey characteristics. Data f the Netwrk t be surveyed is extracted frm the G.IS. Pririty level and survey methd definitin Once all netwrk parts have been put within ne leak survey characteristic grup, tw peratins can be perfrmed : Set up the survey schedule depending n each pririty levels and the date f the last survey fr each cncerned sectins; Design fr each grup the rute the field teams will fllw t perfrm the survey n the mst effective way. On this way, field peratrs dn t have t think abut the way t fllw during the survey and they can fcus n the survey, the equipment and the leak detectins which culd ccur. Definitin f the survey schedule and f each survey ruting A key element f this prcess is the use f gegraphic data and maps in rder t lead the prcess with gegraphic restitutins at each step : peratr can either wrk with data tables r data maps, whichever is mre suitable t the way he wrks.

5 At this step f the prcess, the management f the leak survey peratins has been set up and the data has been prepared t be used within the nbard sftware f the leak survey equipment. The next phase is t perfrm and fllw up the leak survey peratins. Leak survey fllw up and feedback analysis Data transfer frm the management tl up t nbrad data prcessing tls Once survey peratins have been carried ut, all the data cming back frm the nbard sftware is cllected by PISte RSF in rder t perfrm tw different phases : Launching the crrective actins in case f leak detectin; Gathering and prcessing the acquired data fr traceability, schedule updating and keeping the perfrmed rute as a basis fr the next year rute definitin Survey data transfer frm nbard data prcessing tls t the management tl Day after day, nce each peratin f leak survey is perfrmed and the fllwing crrective actins are carried ut, the netwrk perating team can update the prgress f its netwrk survey schedule and make decisins fr adjusting the task frce t be run fr ensuring the schedule t be respected at the end f the perid. This last peratin is allwed thanks t the data feedback which is sent t the distributin netwrk GIS and which is stred within special data attributes within the G.I.S.. Leak survey infrmatin feedback t the G.I.S. fr analysis and prcedure imprvement After each survey perid, leak survey feedback is prcessed and the ptential imprvements fr the next perid survey prcedures are defined. Year after year, survey results are analysed and cmpared and, nce the particular variatins eliminated, it is pssible t evaluate the impact f the successive imprvements. The management tl PISte RSF shuld be deplyed within the next years, after have been experimented within several netwrk peratins units.

6 Develpments : New generatin f survey equipment Onbard data architecture The management tl PISte RSF wuld nt be useful withut a set f fitted nbard leak survey data prcessing architecture and especially leak survey equipment nbard sftware called Géfuite. This sftware added value is n several pints : Sharing data with the tl PISte RSF in rder t use the ruting data which is prepared by PISte RSF and sending back t PISte RSF all the traceability data which has been acquired during each survey peratin. Allwing fr the leak survey peratr t fcus n his survey and prcess the detectins n the mst effective way, with n additinal bligatins such as keeping a trace f the rute fllwed r nticing any unexpected event which culd ccur during the survey fr example. Onbard data prcessing architecture is cmpsed with three key elements : The GPS fr the psitining f the survey equipment infrmatin; The gas detectr; The sftware which gathers the signals sent n ne hand by the GPS and n the ther hand by the detectr (gas cncentratin, defaults, ) during the survey. Additinally, this data prcessing architecture allws fr perfrming sme quality testing, at the beginning, during and at the end f the survey, especially n the detectr, in rder t guaranty the quality f the data. Where peratrs used t wrk with paper maps and written ruting, they will nw fllw the ruting which cntinuusly appears n the screen f the nbard cmputer as lng as the vehicle r the survey equipment (prtable detectr) fllws the frecast rute. In rder t help the peratr t fllw the defined ruting, a vcal device is included in rder t give the driver all the needed directinal infrmatin during the survey. Figure 1 : nbard data prcessing sftware «Géfuite» interface

7 Vcal ruting as well as traceability f the fllwed rute is ensured with the help f a G.P.S. receiver : n this way, any infrmatin is linked t the actual survey equipment psitin when the infrmatin (event, gas detectin, equipment default, ) ccurs. Every secnd, the GPS psitin is linked t, at least, the actual gas cncentratin which is detected by the detectr and this infrmatin, with sme thers, is recrded t the survey traceability files. Once any gas cncentratin (1ppm sensitivity threshld) is detected, the nbard system gives several alarms (windw n the screen, sund frm the cmputer) t warn the peratr abut this new event. At this step, the traceability file is enriched with this specific gas detectin data. At the end f the survey, all infrmatin acquired is gathered and put within a cmpressed file, t be transmitted t the netwrk peratin team in rder t be prcessed and analysed. A first experimentatin release f this nbard prcessing data architecture has been develped and successfully tested by Gaz de France R&D during years 2003/04 (5500 km f surveyed mains). This architecture is peratinal since 2005 n the last generatin f survey vehicles fr Gaz de France Distributin netwrk : the nbard data prcessing system has been adapted t peratinal cnfiguratin with the survey vehicle supplier. Leak survey detectin equipment One f the last pints t be addressed cnsists in the answer t be given t the changes which ccur within the envirnment f the distributin netwrks (especially in urban areas) and their impact n the leak survey carrying ut. In rder t imprve the quality f the detectin (sensitivity, respnse delay, methane selectivity) during the surveys, Gaz de France cllabrated with several ptical detectrs manufacturers since the end f the nineties. The main cncern f Gaz de France R&D team in this field was t be able t find the gd prduct and achieve a reliable test set in rder t be able t qualify this gd prduct t cme fr peratinal utilisatin. On this way, Gaz de France R&D develped a new set f tests in rder t qualify sme unusual characteristics such as signal stability n time, resistance t vibratins, First attempts were nt very successful but in 2005, a new type f detectr came ut with a laser dide based detectr (1.65 µm wavelength) which went successfully thrugh the qualificatin prcess, allwing fr an peratinal utilisatin n Gaz de France survey vehicles. The advantages brught by the ptical detectr fr the peratrs is simplified utilisatin prcedure, with n warming time, a simplified testing prcedures and equipment (tests are perated frm the nbard sftware, nly ne gas bttle is used,..) and a very limited size, allwing fr an installatin in smaller and then better fitted t urban envirnment vehicles. Furthermre, the very shrt respnse delay (half f that f flame inisatin) allws fr surveying faster : survey maximum speed rse frm 20 t 40 km/h which allws fr a better prductivity and mrever a better safety fr the peratrs because the vehicle is nt that slw anymre, cmpared with the ther vehicles n the same rad. Six survey vehicles f this last generatin are being perated by Gaz de France leak survey teams and six thers are abut t be deplyed in 2006, in additin t the eight last generatin F.I.D. which will be upgraded with the n-bard data prcessing architecture. At the end f 2006, 20 vehicles ver a fleet f 27 will be equipped with this traceability and prductivity architecture.

8 Once the nbard data prcessing architecture has been implemented n vehicle, the aim is t develp the same applicatin n the ther equipments used fr leak survey which are at the mment thse used fr the walking leak survey. But when defining the tls fr the future f the walking survey, sme ther parameters have t be cnsidered befre starting any develpment : Areas which cncern the walking survey are very ften difficult t reach, dense urban centers, pedestrian areas; Walking survey requires mre detailed survey than the vehicle due t all the parts f the netwrks t be surveyed (main, service, meter cabinet, undergrund valve, ); Walking survey is very much time cnsuming cmpared t vehicle. Fr these reasns and because imprvement f the walking survey has nt been very much investigated until the last few years, it appears that the walking leak survey deserves a mre ambitius apprach with a gal which wuld be beynd the simple traceability applicatin frm the vehicle t the walking survey equipment. Several ptins are available at the mment fr imprving the way the walking survey is perfrmed : Using remte detectin devices, based n harmless laser beam reflectin t cver the clse area : these devices allw fr cvering wider areas cmpared t a cnventinal prtable detectr; Using a mbile applicatin f the previus remte system n a vehicle s as t carry ut the walking survey and the vehicle survey at the same time ; Using small innvative and lw plluting vehicles in rder t survey the difficult t access areas while imprving the effectiveness f the walking survey (fr example in sme pedestrian areas) where areas are wide enugh t allw fr such a device t be used (sme cnsideratins have t be taken fr nt disturbing usual area activity). During the last tw years, Gaz de France R&D divisin started t wrk n the ptential utilisatins f the remte detectrs. Tw f these cncern the distributin netwrk: Walking leak survey f gas distributin netwrk; Survey f all elevated netwrk parts (utside risers, mains installed n bridges). Leak survey f distributin netwrk gives a gd ptential fr the use f remte detectin systems. The questin f the ptimisatin can be further investigated with the evaluatin f the mbile applicatin f such systems and/r the use f special vehicle fr difficult t access areas. The tests f these last applicatins are abut t start but a special attentin will have t be brught t the cntrl f the ability f such ptical devices t withstand the specific mbility cnstraints (vibratins in particular, lifetime expectancy, signal stability, ). If the testing phase is a success, the ptential fr imprvement f the leak survey, and particularly that f walking survey, is certainly very high.

9 Results Althugh several prmising develpments are still t be cnfirmed r industrialised, this new apprach fr leak survey and the related innvative systems already give prductive results in the fllwing fields: Cnclusins - Effectiveness f the leak survey fr safety increase : this is achieved because f the better fitted survey management and the cntinuus prcedure adjustment. As well, prductivity f the leak survey is dramatically increased thank t the reductin f survey management time, survey rganisatin ptimisatin and mre effective field equipment which allw t imprve survey utput; - Maintenance peratin csts decrease: methane selectivity dramatically reduced the number f false alarms, the expansin f survey area allws fr detecting mre leaks and reduce third party calls. This last pint leads t perfrm mre scheduled maintenance and less emergency peratins; - Prcess safety level and reliability imprvement: better fitted equipment fr envirnment cnditins, less maintenance peratins, less dwntime. On the same way, equipment is easier and less tiring fr the teams, allwing fr wrk incident decrease. The advantage f the glbal apprach fr the imprvement f the leak survey prcess is that each equipment is cnsidered as a part f the glbal system and all needed cmmunicatin phases and data exchange are frecast frm the beginning. The allws fr dramatic time savings when develping new equipment and a better fitted system. The cmplete data management chain ensures the whle survey traceability and the day t day survey feedback which is prcessed allws fr cntinuus imprvements in rder t ffer an always higher safety level and supply quality. The use f G.I.S. functinality gives the ability t prcess a great amunt f data with the maximum effectiveness, saving imprtant time amunt fr the benefit f the field leak survey carrying ut. Nwadays, sme develpment are still t be lead but the glbal system is n the way and the benefit shuld increase within the cming years.