Streamline pipeline integrity data management for Engineering

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good afternoon everybody um my name is andy stevenson i'm the chair of the t-side committee of the institute of mechanical engineers and i'm pleased to welcome you to what is now our seventh tech talk event so we have two chartered engineers and members of the mcgee speaking today we've got samuel from rosen is going to give a talk entitled structural integrity in pipelines failure is not an option and that's going to be followed by king from durham university talking about structural health monitoring protecting cracks in oil pipelines so it was a bit of a reminder and if you haven't joined us before the event will be recorded and we'll be available to watch on the images youtube channel um the last events that we've had have included topics like subsidy cables canal barges stratna rotors and development of the sofia offshore wind farm and t-side net zero projects so you can go online and catch up on those events we're going to take a break over august i'm going to start again in september with the talk in the 9th of september titled minimizing the inspection and ndt work scopes during turnarounds very much kind of process driven process centered we're going to be running our series of professional registration events starting up on the 22nd of september and i'll be following details of that and emailed out to members in the northeast over the coming weeks so finally as a reminder we're always interested in volunteers for for different topics that will be of interest to our members so if you're interested in giving a short talk at a future event please get in touch with me by the email address shown on the screen or by the imac ease near you website so thanks for listening um if anyone's any questions i'd like to ask the speakers if you can submit these by the question panel and i'll relay them to the speaker at the end of the first talk so i will um hand over to sorry to get underway with the first presentation over to you sorry thanks angie uh thanks for the opportunity thanks for the imacky for the opportunity to present today uh good evening everyone and thanks for for joining uh this session so today i'm going to be talking about structural integrity and with a special focus on pipelines the contents of this presentation i'm going to talk a bit about rosen to give you an overview of the company then are going to move to pipeline fundamentals and then structural integrity in general and some elements like inspection damage mechanisms and inspection again integrity assessment repair methods and then some a conclusion okay right so very quickly about rosin uh rosen is a company that is around for for four years it started at the founder's home uh who started the company by himself and today is a is a big company uh with almost 3 000 employees it's based in the headquarters are in germany as you can see in this slide uh rosen has a presence uh in many places around the world mainly on those uh hub cities for oil and gas and we provide pipeline inspection services for about 120 countries uh uh now a bit about rose in uk uh since this is a this is a presentation for the northeast some of you might have heard about mccall engineering macau is a traditional engineering and consultancy company that was founded in 1996 and macau actually is an acronym that means materials and corrosion and welding so this is at the areas of expertise of the company and in 2006 it started to do a lot of joint uh projects with rosen especially in the pos pose inspection work which is the evaluation the analysis and interpretation of the eye line inspection results and this partnership worked very well to the point that in january 2017 macaul became a part of rosen and now all the services that we provided are under the rosen brand okay some numbers about the integrity side uh of rosen because rosen is very famous for the ioli inspection work for for the integrity ma maybe not everyone is aware of it but we have also a big presence in this uh in this activity so we have more than 500 integrity studies completed every year we have 350 customers around in 65 countries globally we have 200 integrity engineers and 20 principal engineers so uh quite a a big team of uh specialists in different disciplines related to pipeline integrity and integrity in general okay uh just my idea of some other services that we provided not all of them related necessarily to integrity some material testing stress analysis flow assurance uh we we also have a base uh in brunswick which is the test facility and also an ili office which is related to the ili business in silverlink okay now let's move on to a bit of pipeline fundamentals just to to try to get everyone on the same page so the basics of pipelines pipelines is the more efficient way to transport liquid gas and solid even solid products for example slurry pipelines for iron oil for example so you mix the ore with water and you can pump it using pipelines which is not not everyone is familiar with uh those products can be transport transported over hundreds of kilometers sometimes even thousands in the oil and gas industry the main purpose of the pipelines is to get the crude oil from the production sites to the refineries where it is transformed in different finished products and sometimes in between you have the terminals that can work as import or export facilities for the crude oil and also for the finished products as well and another another purpose of the pipelines is to transport the finished products from the refineries to the distribution centers my focus here is on transmission pipelines which are usually the the ones that cover larger distances have larger diameters and operate at higher pressures so i'm not talking about the smaller pipelines that we have for example for for city city distribution for natural gas that comes to our houses for example but some of the principles are still the same an important difference in difference between pipelines as compared to other equipment in the oil gas industry is the fact that the pipelines they are not confined to an industrial area so they go beyond and they go over areas that can be sensitive because there might be communities living nearby and also because there are some environmentally sensitive areas like rivers forests and other regions that uh can be affected if there is an incident right in general pipelines have a very good uh safety track record as compared to other alternatives to transport hydrocarbons but unfortunately accidents still happen and this is an example of a high profile accident that happened in 2010 in san bruno california unfortunately eight people were killed 51 injured homes were destroyed and other homes were damaged it was a natural gas pipeline there was a rupture that was followed by by an explosion and fire it was caused by some not igo practice practices during the relocation of a segment of the pipeline and there were some issues with the material quality and as a result there was a flaw in a well that grew with time by fatigue and after a long time a long time after this installation there was this rupture that unfortunately was a very severe accident now i'm gonna talk a bit about uh pipeline uh fundamentals just to to give an overall idea uh it's well there are a lot of details about pipelines but i think for considering the most of its length it's basically the connection of 12 meter carbon steel pipes that are welded together on site uh the main domain for most of those pipes the the design criteria is to make sure the pipe can withstand the internal pressure and it's basically using the barlow's formula of course with some design factors to ensure safety and to take into consideration what is around the pipeline and the products that are transported there are a lot of rules regarding it but the basic assumption is that and then it's considered that the pipeline is under main brain stress which is the constant stress along the wall thickness those pipelines are buried which is uh something uh important because the first thing is that you don't see them so they do a good job for you but you don't have to see them and the fact that they are buried uh also uh gives additional protection so it's very hard for someone to hit a pipeline because it's uh be buried but you see later on that it's still not impossible it might happen uh the products are pumped uh by means of pumps for liquid lines and compressor for for gas pipelines uh most of the pipelines they have an external coating which is uh the objective is to protect again external corrosion which is caused by the soil surrounding the pipeline and as a second uh barrier for for corrosion uh that is cathodic protection because uh after some time is it expected that the the coaching might have some some some flaws and in order to protect those areas with flaws there is the cathodic protection to make sure there is no corrosion at least you to minimize them of course and around the the region where the pipeline is buried you there is a right of way which is an area that uh it belongs it's associated with the pipeline and in this area it's like a buffer for protection and for easy access so it's not allowed to have uh constructions over the pipeline and then you have this well-defined area that sometimes you can even identify and there is some signalization that shows that there's a pipeline buried that so it's another important measurement that's part of the design approach for pipelines nowadays most of the pipelines are pickable which means that you can run ili tools uh along them so i'll go we'll come back to that later so i'm gonna now gonna move to structural integrity the main elements of structural integrity what is structural integrity well it's basically the ability of the structure to operate ing to the parameters it was designed for without any failure it looks a very straightforward statement um usually if the if the equipment had a good design a good material selection and a proper i cannot see my slide properly right now okay if there was a proper manufacturer and construction that should be a given there should be no surprises there but of course uh of course that's not that that is not enough in the long run because for some components uh over time there might be no modification no damage and that's fine but for other equipments because of the environments where they are you might have some issues uh that might modify the equipment and it's important for for the responsible for the equipment to make sure it's still uh possible to to operate under the design conditions if not some corrective actions must be taken or maybe the equipment must even must be derated for example reducing the operation temperature or or the operating pressure and the changes that might happen in a given structural equipment are caused by damage mechanisms that there are different damage mechanisms it depends on the environment the equipment is in so uh a metaphor i like to use for structural integrity is like health for us humans so it's an indication that your body works well there are no underlying issues and you can do everything to the best of your ability but that is translated to an engineering component so for that reason structural integrity must be managed because if that is not the case and if there is an active damage mechanism failure can happen this is a very famous example of the aloha airlines flight that part of the fuselage uh disconnected midflight the pilot managed to land uh the aircraft uh unfortunately one steel address uh was killed because she was not strapped she was standing so she she just flew away and unfortunately died but the other passages were okay it was caused basically by due to fatigue damage and it was this fatigue damage was also accelerated by a corrosive environment right it's a very interesting case to study well now i'm going to move on to the elements of structure integrity uh the main elements of structural integrity uh are the damage mechanisms that are already described which is what caused damage and my affect your equipment uh prevention is a very important part because it's a way to to take actions that might minimize uh the the damage mechanisms after that comes inspection which is a way to make sure that everything is going well you cannot just hope for the best you have to always check to see uh if there's anything uh going on that might not have been expected uh in design for example then it comes the assessment the assessment is where you look at the inspection results and you have to make to to to identify how serious uh whatever you find is so if you have for example uh corrosion with a 50 metal loss uh is that a reason for concern is it okay so for that you need some assessment tools to evaluate uh the damage caused by uh some some defects some some indication you can find in your equipment and the last resort is the repair when uh as a result of the assessment you realize that something must be done in order to re-establish uh the full capacity of your equipment so it's usually a replacement or some reinforcement uh in your structure or component and uh there are different approaches to structural integrity the level of detail to any one of those elements and it's mostly driven by risk so the higher the risk so the higher which is a a combination of likelihood and consequence of a failure so the higher it is more the more refined will be your inspection the intervals will be shorter and you will use more refined assessments to make sure no failure should happen in your equipment so i'm going to talk a bit about inspection uh in in in more traditional equipment especially the oil and gas environment the inspection sorry i cannot see these lights very well uh yeah is the process that allows the damage mechanism to be identified and quantified uh it's primarily visual and complemented by non-destructive testing external inspection usually can be done with the equipment in service but for internal inspection it required the equipment to be shut down cleaned and uh the inspectors need to come inside the equipment to to look and see if there is any damage so the images show that it's not an easy job whatsoever uh for pipelines is a bit different because unfortunately there is no access for external and internal expansion well actually there is access for external inspection but as you can see this is not straightforward if you have want to have a look at the uh fs a small section of a pipeline you have to make a big hole and get inside and do the inspection so uh the the the traditional approach for inspection of process equipment from in petrochemical units doesn't work for pipelines so we need something else but fortunately we do have something else which is in-line inspection inline inspection is a technology which is around for some time is the most effective way to inspect pipelines is basically in autonomous fully automatic uh non-destructive testing the tool travels inside the pipeline it's moved by the transported fluid there is no disruption for the pipeline operation sometimes it's necessary to reduce the flow rate in order to to avoid overspeed of the two which might compromise the inspection quality but on most cases even that is not necessary the tools can not only detect but they can also size they can also sorry they can also size and decay very accurately uh locate features along the pipeline so the the previous picture uh it was uh a field verification that was pointed by the ili two results because all the data is saved and there is a report that that tells uh the date the information the details about the feature that was detected and its location and as i said uh the detection size is very accurate for most type of defects some defects are more difficult to to to to size and detect so each two covers uh specific types of of features so the most commons are those for metal loss features geometric features cracks and to record the pipeline route these images are just uh some snapshots from a video that is available on youtube that shows that can give you a basic idea of how is a ioli inspection so you can see the i like driving along the pipeline and this is for this example is specific for the mfl2 where you have a magnetic field that it's uniform along the the wall thickness of the pipeline but if a discontinuity like a corrosion area is detected there is a leak in the in the magnetic field and that is detected by the sensor and that is the principle of the detection and sizing of corrosion features so now i'm going to talk a bit about uh damage mechanism and still a bit above inspection so the main damage mechanisms are corrosion erosion third-party damage joe hazards and cracking so corrosion erosion is by far the most common damage mechanism in pipeline and can occur both internal and externally the causes of course are different in in on the internal side is associated with the product being transported and on the external sides associated with the interaction of the metal surface with the soil if there is a flaw in the coating and if the cathodic protection is not effective at that specific location it can cause local or general thinning it uh the the the result the consequence of the corrosion is a reduction in the capacity of the pipeline for for loading in terms of pressure and it can lead uh in the end to a leak or a failure depending on the dimensions and the mechanical properties of the pipe it can be prevented by a control in the product composition water removal also using cleaning peaks that basically drag the water away from the pipeline so which because water is a is a is a big uh contribution a give presents a big contribution for internal corrosion and also the use of corrosion in inhibitors can help to avoid internal corrosion and of course our design cathodic protection system uh this is an example of an ili result where each dot here is a feature the along the pipeline which is the x-axis the y-axis shows the the clock position around the pipeline circumference so you can see a concentration of features in the bottom of the line because being a crude oil pipeline the water is usually on the bottom because it's heavier than the crude oil and then there is a concentration of features there i'm gonna have to speed up a bit uh another type of damaging mechanism is third party damage which is when there is a uh something hits the pipeline and causes a dent uh it can also cause a guard where there is also some removal of metal and that gives rise to a different stress state and because of the pressure fluctuation in the pipeline that can lead to fatigue and failure and then there is a specific tool which is the caliper tool that can also detect uh this kind of feature it can be avoided with uh seanalization uh patrolling in the right-of-way and even barriers to to to add another layer of protection to the pipeline uh now uh showing geo hazards which is basically when the soil especially when there is a lot of water from raining it becomes unstable and at some point there might be some soil movement and then you have additional stresses to your pipeline that if they are sideways they can cause recons or buckles and if they are in the actual direction they can cause a collapse which is what's being shown on the on the picture where the pipeline was basically severed in order to prevent them uh some stabilization structures can be built in sensitive areas and also some draining systems can avoid avoid the accumulation of water which causes the instability let's move on time is running out now regarding cracks cracks uh started to become more common cracking issues start to become more common in the last 10 years uh there are different types of cracks that can be present in the pipeline most of them are caused by welding defects also by environmental resistant cracking like scc stress corrosion cracking corrosion fatigue and any crack can potentially grow by fatigue due to pressure fluctuations and pressure cycling in the pipeline operation uh so here you can see different types of cracks with different mechanisms and different morphologies so it's very challenging uh to to address because in terms of detection they can be detected but they cannot be distinguished so there must be an additional uh engineering engineering assessment and judgment to to deal with those features i'm gonna have to speed up so basically now i'm talking about uh integrity assessment uh that is a lot of methods that uh assist in the interpretation of the different uh defects or indications that you can find in the pipeline in order to see if they are acceptable or not they are based on stress analysis fracture mechanics and other methodologies to see if the equipment can still withstand the design loadings so these are some examples of some calculations to evaluate corrosion defects this is an now an example to evaluate uh fatigue damage uh indents so that is a more simple approach and then a more sophisticated approach where the ili information from the geometric to the caliper 2 can be used to create an fe model and get a more refined stress concentration factor that can then be used through a fatigue study and all of that can be done without any excavation which is very uh interesting and then for crack assessment we use the methodologies that based on fracture mechanics approach like the failure assessment diagram that is uh incorporated uh as a procedure in both api 579 and also bs7910 and this would be basically the end result of uh integrity assessment so in the chart on the left you can see the black dots these are the features and uh the y-axis is the failure pressure and the red line is the maximum operating pressure of the pipeline it's not usually it's not constant it changes along the pipeline especially for liquid pipelines so the meaning here is that all the features in this particular pipeline have a filler pressure above the maximum operation pressure so that means that there's no immediate danger but of course uh if the if the feature you're looking at it can uh evolve with time it can grow at some point the failure pressure might uh decrease and reach the red line and as a result it's impossible to understand how quick these growth can take place to reach the the critical value and then we can establish a schedule of how many of those features need to be verified and repaired over the course of the next year so that's the usual uh integrity management approach uh i'm gonna jump this one this is basically the service the integrity service that can be used based on information that comes from specific i like tools well repair methods unfortunately i'm running out of time but yeah we have the replacement a replacement that keeps the pipeline operating yeah sleeve uh composites buffing for removal of cracks recoaching which is always used and then like an overall approach where uh we should look at all the data to have a broader understanding of how your pipeline behaves and to manage the integrity better so uh pipelines are very important are very safe but the uh failure can have serious consequences and that should be avoided with a proper integrity management approach uh sorry for going over the time and last uh just the competency club for rosen where you can get more information if you're interesting of those topics most of the contact is available for free thank you very much sorry for going a bit over the time and actually thank you for that so that was really really interesting really good introduction to um to pipelines so if anyone would like to ask a question um please uh please submit them and i'll read them to um to asario um while we're waiting for you to point out sorry interest in the work that you do what's the split between onshore and offshore pipelines yeah the the onshore and offshore pipelines that they have some different uh construction approaches uh my experience is mostly on onshore pipelines but the officer pipelines for example they are more susceptible to internal corrosion because you basically are working with the raw material which is the crude oil which can have a lot of water associated a lot of salt a lot of sand so it's a really nasty environment uh on the other hand the wall thickness for offshore pipelines is usually determined not by the internal pressure but by the loads during the the the loading operation of the pipeline so you have a bit of a extra thickness uh an extra allowance for corrosion um yeah i think that would be the main difference uh and of course uh offshore pipelines would not be susceptible to to mechanism like sec because it's it's fully wet so there is no uh there's no risk of of the the different chemical interactions that you usually have in a buried pipeline and of course the the third party damage can happen uh for example an anchor for a ship can hit the pipeline but i i would say it's probably uh less likely than for an onshore pipeline but of course there are many other differences you mentioned in the presentation that there was um it was becoming more common to find cracks in pipelines what's the kind of reasoning behind that do you think i think the the main reason is because usually when you have a crack that is associated with a wealth defect if if the pipeline doesn't have a lot of cycling uh it will probably be there forever and it will not grow uh it's it's it's very much the case for for uh gas pipelines on the other hand when you have sec sec it's a time dependent mechanism so you need time for your coaching to to degradate and you uh and at some point uh you have failure in in coaching and then you have this interaction with the soil and the this kind of failures started to happen uh in north america and probably because those pipelines operate at higher pressures and i think that's why it happened there first but in the last 10 years we have seen it happening uh everywhere like south america europe that's still not a case in the uk not so far and no cases in africa but it might be just a matter of time because it's a it's a time dependent mechanism and of course it's also associated with the quality of the construction so if the the construction has a better quality the likelihood of having those failures would be lower okay i just got final final question that's coming um just about rosen and the uk office so do you cover the uk only or do you undertake studies for the rest of the world no we work we work for the whole world actually uh i i'm not i'm not erosion for a long time but i still have done any work for uk i'm currently working for south america and also for some projects in europe and canada but it it used to be a centralized team that uh worked for the whole world and and of course also for uk customers uh clients but we're starting to have some uh teams uh working uh spread to be closer to the clients and to to to to to have a more uh let's say a more uh closely presence but most of the team is here in newcastle excellent okay well thank you very much for your uh your talking style that was really interesting so so thanks for that thank you gonna move on to our second one um so king if you're if you're ready to um to pick up i will let you introduce yourself um on your presentation okay so um thanks for andy okay so good afternoon everyone um thanks for the opportunity that provided by i mechanically so the title of my talk today is structured health monitoring for detecting cracks in oil pipelines at durham our research project covers wind turbine blade measurement battery end-of-life performance evaluation power quality signal detection and control for urban distribution networks to name but few but today's presentation is much more focusing on structured house monitoring for detecting the cracks in the oil pipeline so um someone might be know the acidic which he said in 1914 he said if a thing exists it exists in some amount and if it exists in some amount it can be measured so there are four date measurement scales nominal ordinal interval and ratio so the nominal scale are used for labeling variables without any quantitative value so example of nominal scales are gender hair color and where do you leave a good way to remember all of these is that nominal sounds lot like name and nominal scales are kind of like names or labels and ordinal scales are typically measures of non-numerical concept like satisfaction happiness discomfort and so on so the the slides showing here the hub scale and the pain scale are two good examples of these and with ordinal skills and the order of the value is what is important and significant but the difference between each one is not really known the other scale which is interval scales are numerical scales in which we know both the order and also the exact difference between the values the classic example of an interval scale is so cell temperature because the difference between each value is the same so for example the difference between 60 and 50 degrees is the measure measurable 10 degrees is the difference between 80 and 70 degrees so interval scale are great but we can't calculate ratios which brings us to our last measurement scale and which is the ratio scale ratio scale tell us about the order they tell us the exact value between unions and they also have an absolute zero which allow for a wide range of both descriptive and also inferential statistics to be applied a good example of ratio variable include height weight and duration so when we're looking at some measurement techniques we first look at the data acquisition method normally update acquisition techniques will be classified as non-contact method and tactile method sometimes also called contact method the non-contact method depends on the date being acquired they can also be classified as the optical method acoustic method and magnetic method and for the ou pipeline crack detection we will use both acoustic and magnetic method for the measurement so um i'm just here talking a little bit about the the problems um the ou pipeline leakage is a major environmental concern therefore a safe and reliable pipeline network is vital and currently the average age of the oil pipeline in the usa is over 50 years and due to the various causes and pipeline leakage of more than 110 million us gallons of the crude oil and petroleum products have spelled from the usa mainland pipeline network along and also the underwater pipeline leakage could bring even more consequence to the eco system so an early detection of potential pipeline leakage is very important not only just for the environmental concern but also will have a big economic benefit so the figures on the right hand side is a photo of the in bridge line 60 which ruptured in july 2010 and spelled 24 000 um oil filled barrel of oil into the color muscle river in michigan so these are becoming the largest inland oil spell in u.s history i'm so talking the situation in the uk so the uk onshore pipeline operator association which is uk opa they are the um regulators for the uk pipeline product laws and they have published a report in 2018 so the two figures are put in here are from their report so the last one shows the failure frequency during the period from 1962 to 2016 and which 0.212 incidents per 100 kilometer year so for the last five years for example 2012 to 2016 um which is 0.087 instance for 100 kilometer year so in order to see the result over recent period the moving average for each year is calculated with reference to the incident from the previous five years so for example 2012 to 2016 um 2011 to 2015 or 2010 to 2014 etc so the figure show on the right hand side you can see the development of the product loss incident frequency by cores pipeline philly due to causes other than those defined um on the graph will be classified the first one will be the actin external interference second one which is corrosion and third one is material and construction uh fourth one will be the ground movement and these are generally classified as other um on the on the chart and also these other accounted roughly about 22 percent of the total failure rate so from this we can see that it's important if we can find a good way to do the early detection um which is most importantly um which will be see the environmental benefit and also economically so um when we're talking about method which used for the structured house monitoring um a lot of the peoples were taking a lot of the different measurements so i listed here a few of the method which commonly been used in the on pipe industry and one of the particular one which is the ultrasonic um this this kind of method which can be used to do as a flow detection dimensional measurement and also material categorization so this method they are very sensitive to the surface and subsurface discontinuities also have the high accuracy and can measure the location size and also the shape of the defect and also they can produce the detailed image for the the defect but the also the disadvantage for this type of application is surface must be accessible so that's depending on the condition of the pipeline where they laid and also the extensive training which needs um to master this piece of the techniques and also um difficult to inspect the materials that are rough irregular thin small or non-human skinny human genius so every techniques which list in here they all have the advantage and also the disadvantage depending on the applications um location and also the structure of the the pipes which we actually need to to detect in the crack with it so the technique is in question uh for today's presentation uh is to using the impedance based method um which using a surface-bound uh pedo-electric pct transducer patches so this technique um utilize the p3 effective property of pct transducer patch which they are bounded to a structure acting as both a sensor and also a critter to detecting a change in the mechanical impedance of the hot structure when a defect such as a crack is present so the feature demonstrates the visual electric impact effect on a polarized cylinder of the feature electric material taken as a transducer patch in the case of this project so from the figure a which is showing the transducer patch is the arbitrarily paralyzed positively with the positive charge um at the top of the shape and the negative charge at the bottom and so if you see the b and the e these are presented a compressive stress on the patch this will produce a negative charge and a tensile stress will produce a positive charge so um looking at the b and the c these two figures which is actually you can see the negative the electric field applied will extend to transducer patch and the positive electric field applied will contract it so this is important as it can be see that if a ac signal is passed through the transducer patch it will expand and contract as a current alternative so it can operate it so it can evaporate um in addition it will vibrate at a frequency of ac signal being passed through it as the expansions and also contractions will increase with a fast charging current so um overall the impedance based method use a pedro electric transducer patch driven by a ac current and they are sweeped between a range of the frequencies foreign so for the experimentation and configuration in this work a mild steel pipe was used which has a length of the one meter an outer diameter of 101.64 millimeter and also a wall thickness of 2 millimeter so the coordinate system used to indicate the location of the transducer and holes drilled to simulate the damage described in the figure so you can see from the figures we put the five patch transducers and also the location of the transducers are also shown in the figure so you can see that one two three four five on the different location on the pipe so the baseline impedance measurement of five transducers were made with an undamaged pipe with a frequency range of 10 kilohertz and 20 kilohertz in steps of the five kilohertz subsequently the damage were made to the pipe and impedance measurements within the same frequency range and frequency steps were made for all five transducers the damage conditions invest investigated are listed here where the distance acts and also the angle theater of each of the whole drills are referred to in the coordinating system and shown in the previous slides in order to quantify damage a damage matrix rmsd for each damage condition was compute for each transducer the rmsd damage matrix is the root mean square differences of the damaged impedance from the baseline over the frequency analyzed so where the re k1 i is the impedance of the pct measured under health conditions rec 2 i is the impedance for the comparation with the baseline measurement at frequency interval i and n is the total number of the frequency points used in the comparison so the the figures um showing the rmsd value obtained for each transducer for each of the damage conditions as the rmsd is a measure of the damage the higher the value the more severe the damage is so the damage under condition one and condition two was a two millimeter diameter hole and a four millimeter diameter hole at x equals to zero theater equals 90. it can be seen that the damage matrix obtained under condition 2 are in general higher than that often under the condition 1. under condition 3 five millimeter holes were drilled with one at x equals to zero millimeter theater equals to ninety and one at x equal to twenty millimeter theater equal to ninety so it can be seen that the matrix obtained by transducer 1 and 4 under this condition are similar to those obtained under the previous two conditions while an increase in the matrix can be observed for transducers 2 3 and 5. under condition 4 one more 5 millimeter hole was located at x equals to 20 millimeter theater equals 90 in addition to damage under condition three again there is no significant increase in matrix observed for conducers one and four well marked increase can be seen for transducer two three and five and over the years a number of the researchers have proposed various damage matrix equations to provide better correlation between the matrix and the degree of damage primarily they are variations of the basic statistical model and the more common ones which are listed here which is rmsd1 b2 e3 and d4 i'm coming to the um i'm presenting the results so the value of this damage matrix were computed from the impedance measurements obtained from all tranduces for all the damage conditions so you can see that's the figure a b c and d and which is showing the ims d1 rms d2 rms d3 and rmsd4 the damage matrix respectively so they are not that much different but for the one which the green bar and that's how the significantly different for all the the measurement so you can see that figure a and the b show the ims d1 and ims d2 metrics so the trend showed by the figure a and b are such that there is no difference in the matrix obtained under all conditions for transducer 1 and 4 and the increase in matrix with increase in damage can be observed for transducer 2 3 and 5. so figure c showing the rms d3 matrix and the figure d shows the rmsd4 matrix so from the result obtained it can be concluded that all the damage matrix algorithms show us a similar trend matrix increase with damage apart from rms d3 the results show that the damage metrics are very sensitive to damage see for example condition condition one and two with a single with a single um two millimeter diameter and four millimeter diameter hole respectively there is a very strong correlation between all damage matrix and distance of the transducer from the from the the site of the damage so although the result obtained in the present work have demonstrated that impedance-based method can be used to detect the cracks in the pipelines so we propose the the following with proposed the following work which might be improve the efficiency of the the pipe inspection using pct transducers two first one is to investigate the effect on the damage matrix of the frequency range analyzed second one is to second one second one is to correlate the damage matrix with the transducer distance so as to locate the site of the damage the third one is to adapt the current setup to investigate crack detection using other structural health monitoring method techniques so i think that is everything for my presentation okay thank you very much um so that was interesting um if anyone would like to to submit a question please please do so we'll we'll pass this on in the last few minutes um if i could ask a question is it been um very theoretical or undertaking kind of trials and laboratories where does the kind of technology sit sorry can you repeat questions please um the work that you've done to date has that just been theoretical or you have you done experiments within a laboratory or any field trials yet um so the work which we did we do have the laboratory test rig and so we actually use them to testing or validating our method we currently had some discussion with the bp and we also have a student project with them in the past so um try to introduce our message to see whether they would actually take on or making any real field trip field work on their pipelines yes yes to try and uh to bring the technology on okay that's very very interesting in terms of time skills how um how far away do you see the kind of verification of what you're doing being before that could potentially be implemented into into the field um so i think that's depending on the complexity of the situation on the field um and i think currently you know it's also depending on the the technique which we use um so for the pipeline you can you can have the multiple transducers i think the hard work is actually um the hard work is actually um to reconstruction the image and i think that's a small more difficult to quantify the crack the information the size and also the depth of it okay thank you we haven't got any um any other questions and we'll um we'll bring today's tech talk to um to a close um thank you very much to asario king for giving up their time um i'm presenting today um it's always great to hear what other engineers get involved with um thanks to emma at the imf headquarters for for setting it up and everyone for joining us again and hopefully we will um we'll meet again in september when we have our next tech talk event okay so good evening and thank you thank you thank you everyone thank you