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"(00:00) hello everyone uh this is me ahmed al-gharji as you know i'm an assistant professor at moreto college it is my pleasure to be with you today talking to students of the kuwait university by the way i have many kuwaiti students here also i have a kuwaiti flag in my office so it's always pleasure to talk to kuwaiti students okay so um thank you for the invitation and today we will talk about little introduction about hydraulic fracturing okay so let's begin so to cover the basics of hydraul ic fracturing i need to talk about (00:49) what is formation damage also i need to know what is will stimulation then i will talk about what is hydraulic fracturing why we do it and finally little information about the equipments and material okay so basically formation damage is uh a disease may uh affect my reservoir so this is the the the good way i like to use to teach my students here is always remember that you as a petroleum engineer you work as a doctor you are like a physician when a pa tient feels something wrong with his health or her health for sure we go to see the doctor okay (01:48) so when you talk to the doctor the doctor will ask you what is the symptoms what do you feel what is wrong in your body and most likely you have a disease so the disease this is the formation damage so a doctor is a petroleum engineer the patient is your reservoir maybe a gas reservoir maybe an oil reservoir maybe um you know water and oil and gas all at the same time so there's different type s of reservoirs and this is my patient this is the reservoir we are studying oil and gas in universities to keep these oil and gas (02:35) reservoirs healthy and producible you know producing a lot of oil and gas okay so i want you today to know what is what kind of disease may happen to the oil to the hydrocarbon reservoir also i wanted to know what is the symptoms okay also i wanted to know what is the medicine okay so it should be easy and interesting lecture so please give me all your attent ion remember again when you feel something wrong with your body you go out to see the doctor and the doctor will ask you about the symptoms he will try to do (03:19) some diagnosis to know exactly what kind of disease so he may ask you to do a blood test he may ask you to do a scan and at the end he will figure out what is exactly wrong in your body and he will tell you hey you have this disease and you need to take this medicine of this remedy and in oil and gas we have copy the same concept an d you as a petroleum engineer you are the doctor the hydrocarbon reservoir this is your patient and we are trying to know what is the disease what is the symptoms and what is the medicine okay (03:59) okay so formation damage is a kind of disease but actually it is not one type of disease it is many many many types of diseases okay so formation damage may happen to any formation maybe if it is a sand stone formation if it is a limestone if it is dolomite if it is shale all this kind of you know all of these types of reservoirs may have uh formation damage also this formation damage may happen at any time so maybe from day one production or maybe after one or two years there's uh all you know chances may happen so how to figure out (04:45) um there was a problem with the formation damage problem you may notice there is a loss of will performance the well used to produce let's say 1 000 barrel every day but today you find it 500 you keep asking yourself why you lost 50 percent of your pr oduction so maybe there is a formation damage maybe something else but you need to check that yes maybe there is a formation damage so most likely uh a formation damage cause plugging of poor throats you know that we have pores we have pores inside the formation (05:28) and these pores which is uh the voids include or you know have the hydrocarbon as maybe has some water some gas and some oil and these voids must be connected together so the hydrocarbon can flow from somewhere inside the reservo ir to another place inside the reservoir or reach the world bore and we can produce it easily later so if you plug these channels of the pose throats or the little bottleneck connecting the two um you know pools beside each other if you plug this uh pathway it means the hydrocarbon cannot move to the wool (06:15) ball and cannot be produced okay so this is a formation damage also a change of watability you know that if we are producing oil i prefer to have a water with reservoir a water with res ervoir means your formation or your rock love to keep the water keep the water inside the reservoir and like to produce the oil which is favorable this is what we want okay so if you inject a chemical and by mistake you change your reservoir from being water wet and become oil wet means your reservoir will keep the oil inside it and will produce (07:01) water this will be too bad why because we are petroleum engineers not water engineers we are here in this business to produce oil and gas not to produce water okay i mentioned it it may occur anytime also it can take various uh periods of time okay what else about formation damage it can be simple uh just one type of information damage also it can be multiple types it is similar to an old man who has many diseases okay so when you go to see the physician or the doctor you may have only one problem like high blood pressure for example or you (07:53) may have diabetes or whatever problem but in some cases especially with old men or you kn ow old ladies you may have multiple diseases at the same time okay so formation damage is very similar and maybe just a single you know type or maybe a multiple types okay remember uh we always say if you have let's say when you have a little kid your dad and mom always you know ask you to uh to avoid being sick it is better to avoid being sick then go and see go to the hospital or get hospitalized so it is better always to (08:43) avoid bad things so it is the same scenario here it is always be tter to avoid formation damage than treated why because to treat or to fix a problem or information damage it may cost you millions of dollars and this is not wise to do okay how to identify how to know there's a formation damage problem the same thing if you go to the doctor he may ask you to do let's say a blood test i will ask you to go to a medical lab to get a blood sample from your arm for example and they will tell you exactly you know (09:29) if you have anything wrong or not so also the y may the doctor may ask you to go to a scan place to do let's say scan for your chest or for whatever part of your body but these things we use it to identify exactly what is a problem to know exactly what is what kind of disease do you have okay so the same thing here i may notice there's a loss of wood performance okay but when i notice there's a lot of worm performance i'm not very sure that this is a formation damage maybe a natural decline maybe i still don't (10:08) know maybe i i believe we should do something called plt or production logging tool plt is ver something very similar to when you do a scan for your body okay so you send something over the wire line uh down to your to the wilbur and you will see exactly what is wrong needs a perforation if the perforation produce water which part of the perforation produces that water and how much water and you can later do some uh analysis to know exactly what is the problem okay also i may take a sample i may get a sample uh from (10:51) the fluids down hole and i know exactly what kind of problems maybe there's a bacteria down uh you know uh near the wilbur near the uh perforation like srb sulphur reducing bacteria maybe there is a scale problem near the perforation so i need to check all of that and easily i can take a sample and do some analysis and i can figure out what is the problem also i can send a downhaul camera to see exactly what is going on it is very similar when you have something wrong with your stomach a qualitative to be something quantitative okay so when you have a positive skin (13:09) let's say when i say this reservoir or this formation that has a scan of plus 20 or plus 50 plus 50 this is mean positive skin this mean there is a a damage problem your permeability is damaged okay when you have zero skin the skin factor is zero means your formation or your reservoir is good not uh no damage happen at all and no stimulation happen at all so you are healthy but you did not go to the gym to be ay so this happen when we see the negative skin when we see the skin is let's say negative 2 or negative 3 or negative four it means we did a (15:28) stimulation technique and stimulation by definition means to make something better okay okay so keep in your mind s or the skin factor may be positive means formation damage maybe negative means the stimulation of you make you made the well instead of producing 1000 barrel as usual now it produced 1500 of 2000 barrel so you make it you made the wel he formation okay okay i will explain by details what is hydraulic fracturing just wait for a couple of minutes let's finish first what is uh the different types of formation damage formation damage may be mechanical or chemical mechanical formation damage (17:42) maybe the solids invaded the formation during drilling when we drill we use drilling fluids and this drilling fluids has a lot of uh you know solids suspended and these solids suspended may invade and go to the reservoir and damage the of a chemical reaction happen inside your wool board for example okay so sometimes we have something called sand production and sometimes we call it fines migration so i want to tell you what is the main difference between sand production and fines migration and both of them considered a formation formation damage sand production means you are producing (19:53) some sense go with the oil and gas and water producing for produce from the reservoir and reach the world bore and go to the surface th mber this model because this model will help you to imagine what is formation damage and what is the medicine we have as a petroleum engineer which is maybe hydraulic fracturing maybe acidizing maybe acid fracturing but in this lecture we will focus only in hydraulic fracturing as a medicine as something good we do to the reservoir to make it produce better okay well stimulation remember in oil and gas we have two famous walls one we call it well reservoir simulation and this is like we simulate t is will stimulation (23:22) so let's go to see what is hydraulic fracturing okay hydraulic fracturing simply we are injecting fluid into the wellbore and this fluid we call it engineered fluid which is a fluid with a recipe like you are cooking something a nice food and we need to follow exactly the same recipe okay so we prepare a fat fluid we prepare something we call propane this is the problem and later i will show you what is [Music] the flak fluid and we inject that in a high rate to the very bad okay also after you open your fracture after you crack it this fracture by nature will close again (25:24) so we need to inject some sands we call it perpend this is like a small balls i have many samples in my office okay different sizes like a small balls very similar to sands okay and we inject that why we inject it because after you stop injecting the effect fluid the fracture you created will close again and you will lose the permeability that good permeability you you the good co se until you break down the formation i can keep pushing on something if i am very strong i will break it okay if you break it you will increase the channels that reach the reservoir that connects the reservoirs with the (27:36) wilbur okay so if you look to the left this is a horizontal well and i can inject the fracking fluid again and break down the formation and i can do that on stages okay so if i ask you i will do that because the permeability is very low you'll you will say okay this make the oil and gas and water they will flow through the screen and the sands will stop inside the formation okay so if someone asked you do we do only uh hydraulic fracturing for for low permeability reservoirs the answer is no we do hydraulic fracturing for low permeability reservoirs and also we do it for high permeability (29:40) because of wars but for a different reason which is uh sand control not to enhance productivity but for to stop sand production guys please uh give me all your attenti ] once the casing cement has set drilling of the intermediate section of the hole continues by drilling through the wiper plug shoe and cement at the bottom of the wellbore and on toward the targeted zones throughout the drilling a mixture called mud is pumped down into the well through the drill pipe the mud serves to keep the drill bit cool it carries the cuttings to the surface and provides hydrostatic pressure prohibiting formation fluids from (31:50) entering the wellbore as drilling approa ll production casing is then inserted (33:12) as with the surface and intermediate casing the production casing is also cemented into the hole [Music] back on the surface the drilling rig is no longer needed a temporary well head is installed and the location is prepared for the service crews will ready the well for production the first of these steps is to perforate or perf the casing a perforating gun is lowered by wire line to the lowest of the three target zones an electrical current is sent f the zones into the well the next step is to install a permanent wellhead and other necessary surface equipment sometimes a pump jack is used to help (35:05) bring the oil to the surface the final step is to install and connect the pipeline to the well that will transport the oil to the nation's pipeline network wells that produce from several zones simultaneously result in greater cost efficiency and increased productivity okay so the good thing about this video you know it summarized a lot of the bottom hole pressure will increase increase increase until the breakdown will happen okay then i will do some after i stop injecting i will do some will testing to get some uh you know information about the reservoir and to know to evaluate their fracking (37:12) job okay so try to memorize that in your mind okay so what is the applications of hydraulic traction we use hydraulic fracturing to enhance productivity to make a well that produce 500 barrel a day produce 800 or 1000 okay so we we l get fractured unintentionally like by mistake i don't want to fracture this formation but because the cooling down effect in the you know in this for this injector in our water flooding project it gets fractured unintentionally okay also here in the united states and many other countries sometimes we use hydraulic production as a disposal technique if you want to trash your dev cuttings (39:25) if you want to trash any any produced water you can find a location under the ground like isolated z is very crowded let's say during the rush hour let's say from let's say 2 p.m to 4 p.m for example every day and this square very very crowded and has many traffic jams and you know sometimes during summer some cars let's say because of temperature stop walking or any problem happens sometimes there's some accidents happen because of there's many many cars in in in one place and hydraulic production is very similar like you are using a highway instead of going (41:32) through when you finish yo and later because we found this this darcy law (43:01) this equation very helpful in oil and gas we start adopting the same equation and any production book in oil and gas now you will find it maybe in chapter one or chapter two you will see darcy low one of the very basic stuff in in our industry so the basic model that henry darcy introduced he has a pipe this pipe okay and we have two points a and b and this pipe has a lens also it has a you know and a cross-section area the diameter and the in the bathroom if this pipe is bigger for sure it can get you more water okay so try to remember what i will tell you right now if you can increase the contact area (45:10) between the reservoir and the world bore for sure q of the production rate will increase this is the same concept it is not me who told you this this is henry darcy who told you this okay because look to henry equation or henry law or darcy low increase the cross section area a you will increase q automatically okay so if i tive pass from the reservoir deep inside the reservoir and brings all the oil and gas and water directly and immediately to the wool board okay so now i am enhancing the conductivity the conductivity is the fracture width times the fracture permeability okay so this is a second reason why a (47:22) hydraulic fracture increase productivity the first one because increase the contact area between the world and the reservoir the second because i'm creating a conductive pass and increase the conducti pumps hydraulic fracturing pumps and here is hydraulic friction pumps and we have the manifold in the middle and we have something called the blender here in this side if you look to the other side you will see the wheel head here okay so we may have pumps we may have tanks this thanks for the water for the problem for the chemicals also we may have blenders the blender this is like the mixer that makes the fat fluid with the problem with the (49:29) chemicals and mix all of them together and s o that the job supervisor has a might has a mic has a (50:50) headset and he can talk to all the frag uh you know uh theme in the location and give them a direction when to inject when to stop when to increase the problem concentration and so on okay so i used to track my students here and ask them some funny questions and i i show them this picture and i ask them hey try to find me where is uh uh work overview and they keep looking in the picture and someone say hey there walk over egg is here countries is a very big challenge let's say here in the united states when we frag shale we we consume a lot of fresh water and if i wanna uh you know frag organic shale in kuwait or in saudi i (52:53) may get a big big question mark about there is not enough fresh water in the country to use it in in in fracking this is why we don't develop shale uh these days in in kuwait or saudi or even in egypt or you know in libya or algeria there there's a lot of organic shale but we cannot develop it ea this guy we call it fluid tech he work in the as a in the frog team and he prepares a fake fluid okay look the here is a guar look to this picture here is agua and it's very similar to beans see this (55:21) is beans here we we get the the seeds then we grind it we we you know we we mill it so it become like a powder we mix this powder with water it becomes something like a milk here this is a milky uh you know uh liquid if we add cross linker gel because you know if we add crosslinker which is nt gelling agent scale inhibitor breakers ph adjusting ion control bios a lot of things okay and because of these chemicals hydraulic fracturing in most of uh european countries is banned there is no fracturing in germany there is no fracturing in france for example because they like to (57:49) keep the environment as it is and they don't like to inject these chemicals underground okay why does he do it this way because he have green political parties in in in europe and you cannot approve doing mation i need to know an estimate for young youngest models and poisson's ratio of that formation then i will decide what should be the right proponent size for that formation also i need to know an estimate for the stresses in this formation to know how strong must be uh my potent because if my potent uh is not strong enough will get it will get crushed after that by the by the airs (59:44) stresses okay and they want to keep my opponent uh as it is and not crushed look t"