transcript

"(00:02) so good morning good afternoon and good evening hope you are all doing well and staying safe i am mariam shreve a senior petroleum engineering student at the lebanese american university and i'll be moderating today's session so welcome to the second session of the course titled introduction to wealth stimulation presented by a distinctive speaker with an extensive experience in the oil and gas industry dr ahmad elgar so let me reintroduce dr elgarhe dr elger is the director of pio petro a non-profit educational project he is an assistant (00:36) professor at mariata college ohio usa where he teaches hydraulic fracturing geomechanics and unconventional reservoir evaluation and development dr elgarhi holds a phd degree and a master's degree in petroleum engineering from texas tech university besides he holds a master's degree in petroleum engineering natural gas engineering postgraduate diploma and a bachelor in science of science and mining engineering all from cairo university in egypt dr elgarhe has over 11 years of olanga's industry experience with operation and (01:12) service companies that focuses on hydraulic fracturing geomechanics and unconventional reservoir evaluation and development prior to uh prior to working for mariata college dr elgarchy worked for advantage international ogs halda petroleum company texas tech university and solomon and associates moreover dr ugarhi published many journals and research papers with elsevier spe as wla and arma in addit ion he filled two u. (01:45) s patent applications to increase hydrocarbon recovery in both conventional and unconventional reservoirs so please join me in welcoming dr elgari and on a final note if you have any question related to the technical content of the presentation please feel free to drop it down in the q a section and for any comments please leave them in the chat box and please don't forget to do the quizzes assigned after each session they are posted on the google classroom and witho ut any further ado dr agar he the mic is yours mariam thank you very much for the (02:20) introduction uh again this is a second lecture and the course title is well stimulation so please remember when we talk about will stimulation most likely i will mention four things i will talk about formation damage i will talk about hydraulic fracturing i will talk about acidizing i will talk about acid fracturing so whenever you hear the word well stimulation and again don't get confused between well sti mulation and and or and reservoir simulation because many students get confused they don't know the word (02:59) stimulation again whenever we say stimulation we mean uh how to enhance the productivity so if you want to study how to enhance the productivity you should know uh how to do hydraulic fracturing how to do acidizing and how to do acid fracturing and also what is damaging your reservoir and what is damaging your permeability which is uh deformation damage you know uh all types of format ion damage so let's begin okay so before we start as usual because um uh piopito uh when started was doing only services for students and these days we are (03:41) also offering services for companies so please don't get confused we have the blue logo which is uh fire pit of students and we have the red logo pio patrol professionals and fire pit consulting and these uh two things are read logos this is for companies not for individuals not for students okay so uh one more thing tomorrow we will have the first lecture of field development geo mechanics by the way i'm a big fan of geomechanics and i started my work in oil and gas as a geomechanics engineer so i am encouraging all of you to register (04:23) in this class with dr mohamed sawz by the way hamid service one of the most you know famous geo mechanics engineers here in the united states he's not at all but again he has very good experience and it is enough to say he is one of dr mark zuback students okay so how to register in hi s class you have section one code here look at the mouse you have section two uh google classroom code and please if you wanna register try to use the section two first so because sometimes when you whenever you register in section one you (05:01) find it full so you cannot get the chance to register so try to use section two uh first and don't forget to register only in one class one section okay okay uh the last note the class by engineer johannes uh delayed to february so he is not available pump okay this pump most likely 2000 horsepower there's a bigger pumps like let's say 2 300 2300 horsepower there is smaller one sometime to 1600 or 1700 but the most common one is uh 2000 horsepower per each so you can count them one two three four five six seven eight and maybe in the other side there is another eight so eight uh so the total is sixteen sixteen multiply by 2 000 so you have 32 000 horsepower in this location (08:04) okay this is a big hydraulic flight job the jobs we used to d e tanks different shape of tanks for the propane and you (10:09) will see different shape of tanks for chemicals okay also you will see the most important part in the job is a blender so on this side this is a blender and the blender is um let's say the heart of this job or the the main part of the job because the blender is like the mixer we mix the frag fluid with the chemicals with the problem and we prepare it to send it to the manifold then from the manifold to the pumps from the pumps back here is a wheel head okay the second question where is our cover egg most likely in egypt for example in the western desert whenever we do a frag job sometimes we do it with a work over egg a work over egg is a (12:54) smaller leg very similar to a dwelling greg but it is smaller at will and greg we have three pipes we connect them together and we call it the stand this is the three pipes so the total will be roughly like 90 feet and if it is a a big rig like the deep water egg maybe it is four e will handle this pressure which is maybe a double or three times the pressure that can handle i can get something like a syringe like a pipe and put it from inside the christmas tree go deep deep deep from all the christmas tree and we sit it below let's say the casing hanger so the high pressure can go through this pipe and all the valves (15:43) that is the swivel walls and all the valves of the christmas tree is open and this steel pipe go through and until it reaches the casing that you kn rrying the wellhead itself okay with that you know the frag head itself okay so uh second i need to mention some uh materials the materials we are using and hydraulic fracturing again this is a very big job you will never see this in egypt or in saudi or in kuwait this is too big but we have just big jobs here in the united states because we use these big jobs to frack organic shave to flex shale formation and we don't have any shale activity in north (18:36) africa or in middle east in general uh for my another company look to the camera different size (20:51) sometimes it's a bigger ball sometimes the small balls and it is very similar to sand but it's the same size okay and here is more and more samples okay also uh we use a lot of chemicals many many many chemicals and these chemicals one of the main reasons why in europe they don't like hydraulic production because it says these chemicals will harm the environment so we we we may use crosslinker to make the fluid viscous and i wi hibitor like ph adjusting agent like breaker like crosslink iron control corrosion inhibitor biocide and some acids and friction reduce why we use friction reducer because we need sometimes we need to (23:40) over we need to enhance the pump ability i need to inject this frag fluid in a higher rate and it will cause a lot of friction with the pipes so i need to add something called friction reducer to to minimize these friction and let me inject in a higher rate okay so these chemicals this is t link gel very similar to jello okay please look to this video watch this video and this is a real video from a fracking location and this guy by the way we call him uh fluidtech fluid technician okay look nice this (27:14) see this is exactly what the spark fluid this is the fluid okay here in the us the they sell some stuff for the kids in in toys stores we could slime slime something very similar to this viscous fluid and the kids they play with it okay so this is what is frag fluid looks like the sieve that has 16 holes and cannot go through the sieve that has 30 holes in one square inch so this bowl can go through the bigger sieve which is 16 and cannot go through the smaller c which is 30. (30:14) so we call this propane 16 30. okay a second example look to 3050 i will have two screens sorry two sleeves and the first one has 30 hole in one square inch the second one has 50 holes in one square inch and these sands can go through the sieve that have 30 holes and cannot go through th ch formation is different if you create a crack in a glass it will be different from if you create a crack in a wood or a plastic sheet okay so whenever each material has a different different mechanical properties different youngest modulus different (32:53) poisson's ratio so if you are expecting that hydraulic fracture will be very narrow i must use smaller propane otherwise the problem cannot go through the fracture cannot enter okay if you know the fracture is wide so use bigger bowls why b know the magnitude of the minimum stress you can get a problem has a strength larger than this value and you know that this proton can resist and can stay inside this formation without getting crushed or at least you know most of it will not get crushed okay so let's talk about what is principal stresses and what is mechanical es model in the next lecture i will talk to you about how to design a crack and also i will talk to you a little bit (35:44) more about mechanical es modeling because thi aults which is we get a big crack in the earth's crust (37:50) or maybe you know and you know something like this and we have three different types this is not the only type of foods but this is the most common ones three fold regimes this is the most common and famous ones okay so look to this one at the top we call that normal fault system or no normal fall regime we have a crack and if you do the crack it means there's two sides and the side will get slide down so look again this side look at ontal one of them larger than the other so with the larger the largest one we call it maximum horizontal stress and the lowest one we call it minimum positive stress and the vertical one this is the overburden (40:48) and in all cases we must have a vertical one which is the overburden the two horizontals the angle of the direction of uh of the minimum and maximum may uh change from a location to another location okay so in this one sigma one here in the normal floating system sigma one here whi so if the movement is upward means the weight is less so the horizontal stress is pushing the weight upward so in this case in the middle you will see the overburden is the lowest in magnitude at the top the top one the normal faulting system the overbuilding will be the largest in magnitude okay the one at the bottom you will see the overbuilding magnitude in the middle (43:47) between the maximum stress and the minimum horizontal stress that's it and at the beginning i told you the largest mag 5:45) uh you know plotted in this location and for sure if you see a fault like this means this this is the direction of the maximum horizontal stress and i will tell you why later okay also you can do some failure uh analysis and this failure of analysis can let you know the direction of the minimum and maximum of the stress how to do that look here to the bottom the corner okay this is a well bore and this is a mud pressure when you dwell if the mod very low all your ball will collapse if look re is the direction of the minimum horizontal stress okay why the direction of the horizontal stress is important simply because when i (48:34) want to drill a horizontal well i have two options i should drill it with the direction of the maximum horizontal stress and they will ask you this is right or not or i will dwell it with the direction of the with the minimum horizontal stress and i will ask you this is right or not so if i ask you which one is better to dwell the horizontal lateral of t you are doing this is a idiotic mistake okay so i need to know what is the direction of the minimum horizontal stress to dwell with this direction why because it is not a dwelling story after i drill it i need to frack it when you flag by nature the track will be perpendicular to that so i can do (51:20) many many many factions okay so if i ask you which one is easier to dwell you will say is a top one this is easier to dwell but it is not a dwelling story i'm talking about the whole whole life e general information about the well its location and uh the mechanical properties of this well mainly the reservoir and the top the upper section and bottom section okay so i need to know the mechanical uh properties to enter it to the software to the simulator okay so if you don't if you don't know how to uh calculate the mechanical properties how you will select the problem size how you will select the proton type you (54:04) don't know i told you there's a big relation between the problem si extremely explanations (56:16) you will find that some experts will tell you this explanation as a group of experts will tell you the other explanation but i want to tell you both explanations okay why we call them quad why we call them quiet and they are five and why we call them triple and therefore okay okay so mechanical es model i need to calculate the minimum horizontal stress i need to know the direction and the magnitude of the minimum total stress i need to know the value of poisson's likely the mini-frac we do it before fracking leak of tests we do it during drilling after we set the casing it is a test to test the casing shoe and also to predict the maximum value of the (59:04) mod weight i will use in the next section when you do the next section so it is most likely will know it or you will study that if you work in drilling more ballooning is sometimes when you drill a low uh perm uh formation sometimes this formation will take some uh fluids drilling fluids and after y amic measurement and static measurement and i will tell you exactly what is that very very soon so here is what is poisson's ratio if you get a class and material i believe most likely all of you you get that so poisson's ratio is the lateral strain over the longitudinal strain we call that poisson's ratio if you speak french you should know what (1:01:49) does the poissons mean what does poisson mean poisson means fish but poison is a name of one of the most famous scientists ever he was french use it is a strain of a strain so no unit for it okay but for youngest models we measured by psi and youngest modernist is a measure of solids stiffness it was a measure of uh deformation or you know for a measure of elasticity when you apply a load okay and youngest models is stress over strain (1:04:31) okay here is one of the most important questions the youngest model is value i'm getting from using will logs is it the right one i'm using we calculate sonic we calculate the youngest modulus what you get is the dynamic so you need to convert the dynamic youngest models into static english models to finish your design correct so there is many equations to convert dynamic to static here is i mentioned here's like a 10 equations here is 18 equations now it becomes 25 equations which one of them is correct which one of them is accurate trust me all of them are wrong no one of them correct do you know why because if i develop a correlation to (1:07:28) convert dynamic youngest models to or your area how to convert dynamic english models to static in a good (1:09:29) accuracy and less uncertainty okay so this is one of the major uh questions if you work as a geo mechanics engineer how to do that conversion uh with the maximum accuracy okay so here is my conclusion it is very hard to convert dynamic to static modeling mainly i'm talking about endless models it is very hard to convert dynamic angus models to static english models and what we need to use in our design is a static o the formation to the world board makes sense and if the spoken get crushed means you were you are losing the conductivity or the permeability of this problem okay so the right answer is uh the first one to avoid open (1:12:26) crushing and losing conductivity okay the third question which horizontal world direction is easier to dwell this is a very confusing question dwell parallel to the minimum horizontal stress or dwell parallel to the maximum horizontal stress if you dwell parallel to the m nd the minimum horizontal stress what should be the hydraulic fracture look like okay one more time if the overburden which is applied vertically okay and this is the minimum and i told you the hydraulic fracture will be perpendicular to the minimum and in this case the vertical is the minimum so the hydraulic fracture will be horizontal fracture (1:15:16) which is very weird but yes this is what will happen if you have if you in fact in a very shallow reservoir like let's say two thousand feet every reservoir will have different mechanical properties and based on the mechanical properties mainly the youngest modulus and the minimum horizontal stress i will select my problem so the right answer is the first one so [Music] here is the result and let's uh take some questions so i'm done with the lecture and please marry him if you have any questions please go ahead thank you doctor for this informative session uh now we will begin by addressing the questions so the first question states blends things it makes things this is like a mixer you have in your kitchen and maybe you can you want to do let's (1:20:03) say uh add a banana with some let's say uh strawberry and some milk and some sugar and you mix all of them together so the blender because i'm using a purple i'm using fat fluid i'm using the crosslinker i'm using breaker i'm using a lot of chemicals and i need to mix all of them together then i need to send them to the pumps because the pumps will send them to the to the he cases you know if you go to to see it by its definition let me get you here is the definition it is a ratio of the volume change of the fluid filled porosity to the volume change of the rock when the fluid is free to move out of (1:22:40) the rock so what is you you cannot measure it as a if you walk let's say for apache or halibut you will not measure it only you will measure if you have cools and your job or you your job is to get me a specific value or an accurate value for bytes constant tivity of their next year for example okay so you can say i'm planning to uh fracture 100 wills in my company this year into in 2021 and i'm planning to acidize 50 worlds and i'm planning to asset track another 50 words (1:25:14) okay so as a reservoir engineer you can input this data to your visible model and input some you know inputs and the model can calculate an estimate for the increase in productivity okay but again this is just an estimate before you do it and you get the the right numbe assigned quizzes after each session and do the final exam which will be held at the end of this course the dates will be posted on the aoga facebook group and now that's all for today have a nice day stay safe and see you in future webinars thank you"