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From Fossil To Fuel™
From Fossil To Fuel™

Episode 7 · 2 years ago

Episode 6 - Drilling a Well

ABOUT THIS EPISODE

How the well is actually drilled and the things that we look out for.

My name is Brennan McDougall and I'm a professional engineer. Or the last decade I've worked in many different facets of the oil and gas industry. While I have a pretty solid technical background in oil and gas, I don't really know a whole lot about the other non technical departments that help run an oiling gas company. Recently I took a course to help develop my business acumen and better understand how the financial side of the business works. What a novel concept to educate the technical people on the business and financial side. I thought it would be a really cool idea to return the favor and educate the non technical people on the technical side. This is how the concept from fossil the fuel was born. Through these twenty four episodes, we will take a journey from how oil and gas was formed millions of years ago how it is refined into the fuel that runs our cars and keeps our homes. Come join me on this adventure as we learn how the oiling gas industry operates from fossil to a few...

...before you even drill a wall, there's a lot of planning that has to go into making it happen. Where exactly are you going to drill? In which direction are you going to drill? How long do you want or need the well to be? Are there any roads near by? Do you have to build your own? Are there any pipelines nearby, or do you have to build your own? Are you in the middle of nowhere or other services available near by? Remember, everyone you hire has to drive their people and equipment to your location, and it's not cheap. How are you going to get water and fluids to and from location? Are there any local or federal rules and regulations that may impede your operation? Are you going to drill one...

...well or do you want to drill multiple wells? If you live somewhere north like Canada, is winter going to impact your operations or, more likely, how is it going to impact your operations? What about wild life? Some areas are restricted during certain times of the year. Are there any residents, or perhaps other operations going on nearby that will be impacted? This is only a sample of the long list of questions that need to be answered before you can even get started. It's no surprise, then, that some of the more complex wells take years to plan before they are ever drilled. However, once you figure out what you want to do and where you want to do it. The general process goes a little something like this. The drilling rig is trucked out to the location in pieces, kind of like little lego building blocks. Therefore, you'll need to take some time assembling all of the little lego building blocks and connecting all of the electrical and hydraulic lines together. Once...

...the rig is assembled, you'll typically do a very thorough inspection and drill a pilot or conductor hole. Sometimes it's drilled ahead of time for you, but essentially it's there to isolate the very top part of the earth. It's kind of like if you're drilling or putting a screw into a piece of wood. Sometimes you'll pre drill a hole with a drill bit before you actually put the screwing. So that's kind of like what we're doing with the conductor hole. You're pre drilling a hole before you actually drill the well. So these conductors typically are less than fifty meters deep. But once the hole is drilled, the conductor casing is inserted into the hole and it's cemented in place. The way each set of casing is cemented in the hole is by pumping cement down the inside of it so that as you pump it down the inside, it comes out the bottom and back up on the outside and it fills the hole...

...between the outside of the casing and the inside of the whole. Is that little space between the outside and the casing and the whole or the ground. Remember, this is called the ANNULUS. The cement in the ANNULUS will help keep the casing in place and prevent anything from coming up the outside or the annulus of the casing. This process is basically repeated until you reach the target depth. Generally speaking, the deeper you go, the more sets of casing you have to run. Not always true, but pretty good rule of thumb. So drill a hole, insert the casing cemented, going with a smaller bit that will fit through the casing you just cemented. Drill to the next stepth insert the smaller casing and cemented, going with an even smaller bit that will fit through that string of casing, and drill to the next step. Insert casing and cemented. This process continues until you're done. Sometimes it could...

...only be one set of casing and you drill right from surface all the way the bottom without stopping. Sometimes you're running for more sets. Really just depends on what type of well you're trying to drill and how deep it is. In most areas you're required to at least set the first string of casing, which is called the surface casing, and that's finished somewhere below the water table. Generally, in order to protect the groundwater from any oil and gas contamination, most drilling rigs use drilling mud that is made from either oil or water, but for the surface section you should use water based mud, usually because if you're trying to protect the ground water from oil and gas contamination, you don't want to be using drilling mud made from oil. kind of makes sense, right. Drilling mud made from oil does have better drilling properties than water based mud, but it is much more expensive, simply because you have to...

...buy the base oil and you can get water for basically free, depending on where you are. There's a lot more involved in deciding what type of drilling mud you're going to use, but we'll keep it simple here. So just understand that, generally speaking, oil based mud is better but more expensive. So you just have to decide on whether you're okay spending the extra mula on it. The next part that needs to be considered is what type of bit you're going to use. As we mentioned before, the two main types of bits are PDC BITs, and remember, PDC is poly crystalline diamond composite. I know that's long, so we'll call it PDC. So PDC bits and roller corne BITs. Roller cone bits are most commonly come with three cones, which is why most people refer to this type of bit as a tricne bit. Tricone bits where the main type of bit used until probably two decades ago,...

...when PDC bits were really introduced, but since then PDC bits have grown significantly in popularity. You probably don't know this, but diamonds are actually the hardest known material on earth and are named for it too. The word diamond actually originates from the ancient Greek word for unbreakable PDC bits. Remember, they're called polycrystalline diamond composite. Bits are made up of synthetic diamonds, because there's no way in hell we'd be able to afford real diamonds. The body of the bit is made from metal or Matrix, which is, if we're getting technical here, it's tungsten carbide grains, bonded or mixed with a softer metal. So Tungsten carbides like a really hard metal and it would be way too expensive to make the whole thing out of synthetic diamonds and it would be too brittle. So in general, the harder the material is, the more brittle it is and so it can get damaged on impact. So we use PDC...

...cutters which actually contact the rock and scratch it away and braise them or put them into a less brittle body of the bit. So the whole bit actually isn't synthetic diamond it's just these little nubs or cutters on top that actually are the poly crystalline diamond cutters. The body of the bit is that Metal Matrix that we were talking about. That way we combine the hardness of the diamonds and impact resistance of metals. So it's kind of similar in or analogous to using concrete and steel to combine their properties in reinforced concrete, which allows skyscrapers to be built. So the easiest way to describe the difference between a PDC bit and a tricone bit is that a tricone bit consists of three cones, which rotate on bearings and they crush the rock. On the other hand,...

PDC bits are a solid body with no moving parts and they scratch or sheer the rock. Since tricone BITs crush formation, they tend to perform better in hard, brittle formations. However, over the past couple of decades, the PDC technology is seen vast innovation and improvements, and now PDC bits of largely outcompeted tricone bits in almost all applications. To put it in for effective in one thousand nine hundred and ninety PDC bits accounted for only five percent of footage drilled, while now they account for well over ninety percent. This is because PDC bits tend to drill faster, last longer and have no moving parts, which is key because if you have moving parts they can break off and fall down whole and cause major problems for the drilling operation or potentially operations after the...

...drilling rink is left. The last thing we need to talk about is directional drilling. So you're drilling a hole where the bottom is multiple kilometers away. How do you know where you are and where you're going when you can't see anything? Unfortunately, we don't have cameras down there when we're drilling, and you can't use GPS satellites like you do in your car when you're three kilometers below the earth's surface. So what happens is that their directional drillers use a special system of tools that can measure the inclination of the bit and the magnetic direction from north. By knowing how far up or down you are, which is your inclination, and in which direction you're heading, you get this from your magnetic north you can use basic trigonometry to pinpoint the location of the bit. By continuously tracing these dogs ut's as you're drilling along, you can effectively...

...draw a threedimensional path of the well. In cases where magnetic readings can't be taken, you can use a gyroscope to help. Technology has come so far that these tools by the bit can measure more than just the position of the bit. You can figure out all kinds of properties of the rock to make sure that you're where you need to be. So this is all great, but how do the drillers get this information and how do they get it live? Well? The most common way, believe it or not, is for the tools to transmit pressure signals through the drilling mud, just kind of like Morse Code. So these signals, or pressure pulse signals, are picked up by sensors on the surface and can be decoded. However, there are some tools that transmit electro magnetic signals straight to surface. I personally have never used these before, but they tend to be a little less reliable and the signal gets weaker the deeper you get. The newest and most expensive and most reliable...

...method is to actually have electrical wires built into the drill pipe itself, which allows the electro magnetic signal to be transmitted through the drill pipe. This allows for extremely reliable signal and high bandwidth, but comes at a very steep price and so is therefore very rarely used. Again, I've never used that personally myself either. Once you've finished drilling the well, you got all your casing strings in. They've all been cemented in place. The top of each casing string will sit inside the well head, which is at surface, with each one sitting inside the previous one. We'll talk more about wellheads and episode fourteen, but just know for now that the well head is where all the casing strings come together. And is generally the last piece to put on before you finish drilling the well. Hey guys, if you like today's episode, make...

...sure you subscribe to the podcast. Unlike most podcasts that release an episode every week or two, I did all twenty four at once, Netflix style, so you can listen to them all right now if you just hit subscribe. If you like today's episode, make sure you leave me a comment or thumbs up, or you can email me at from fossil to fuel at GMAILCOM, or look me up on Linkedin. I'm Brendan McDougall.

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