I also want to send a special greeting to all communities that support content related to science, technology, engineering and mathematics (STEM), it is important the work and support of the community #STEM popular in supporting this type of content that is published on the platform of steemit.
In this same order of ideas I want to share with you this article with unpublished characteristics and with that very characteristic touch of the topics that are developed in the engineering area.
For this opportunity I want to organize all the drilling equipment in sets or systems, taking the opportunity to describe many of the functions that these teams and systems have within the process of drilling and building an oil well.
The fundamental purpose of this post is not only to show and explain the components and systems that make up a drilling rig, but also to establish a degree of importance given to the organization of these systems when attacking any operational failure at the time we are drilling the oil well.
What scheme could explain how the drilling of oil wells and its components works?
Trying to scrutinize among the public domain images of wikimedia commons, I found the image of a drilling tower, in which as main characteristics is the description of each component and each process in an enumerated form, the image on which I will base to make the description of the most important components is the following:
What components interact to in the process of well drilling?
Making a description of image 1, you can see that:
1] This is the mud tank, and is the reservoir where the drilling fluid, also called drilling mud, is stored.
2] It is the agitator in the mud tank, which is responsible for stirring the components that make up the drilling fluid so that it maintains its properties as dictated by the drilling program.
3] Suction line, the suction line ends up being the means of communication between the mud tank and the suction pump which is at the end the component that sucks the drilling fluid from the tanks to the bottom of the well.
6 and 8] Vibrating hose and standpipe, the reason I combine these two components is because the drilling fluid flows through these two parts in the same way.
9] Kelly hose, as shown in image 1, point 9 is the continuity of the same hose where the drilling fluid circulates, except that it is called kelly hose because it is below the goose neck.
10] Gooseneck, the gooseneck in image 1 is the top of the ends of the circulation hose that looks like an elbow, perhaps many wonder why they have these strange names, remember that much of the knowledge inherited by the North American industries was from a technical term that contemplated these names that today is very common to find in the oil industry, especially in drilling.
In general, in image 1 you can follow the route from 18 to 26, which is where the drilling fluid comes out again at the bottom of the well until it passes through , which is the flow line (return line) that is the pipe that is connected from the wellhead to the distribution line so that finally the drilling fluid reaches the vibrating screen, which is the equipment that filters the mud from the solid parts with which it can come from the bottom of the well until it reaches the mud tank again, thus complying with the circulation circuit, which is continuous and constant in the drilling of the mud.
The above, together with the components and equipment mentioned, make up what is known as the circulation system.
It is important to emphasize that there are components of a system that are repeated in another system, this is because for example, the drill string belongs to the rotation system since the string rotates while it is being drilled, however it also belongs to the circulation system since the drilling fluid circulates inside the drill string.
The rotation system is those components that interact with each other to rotate the drill string, also belong to this system all those components that rotate, all with the main function of being able to rotate and facilitate the cutting of the rock at the bottom of the hole while drilling.
If you follow the route in image #1, you can mention the following elements that make up the rotation system:
18] Swivel, as its name indicates the swivel is in charge of rotating the drill string, in well drilling it can also be obtained with the name of kelly joint.
20] Rotary table, the rotary table rotates because the swivel rotates it, when the rotary table rotates the drill string.
This rotary system within what is known as rotary drilling is now obsolete as it has been replaced by a rotary unit called a top drive, the top drive receives the necessary power from the electrical power source to directly rotate the drill string, I will now show you the top drive component within the rotary system:
The first element you see in the image from top to bottom is the hook which in image #1 is the point , below the hook is the top drive which is the element whose current technology is applied to rotate the drill string.
The use of the quadrant or kelly joint cannot be completely discarded, since from operational experience I can tell you that when I was working as an operations engineer, one of the drills at that time the PDV-62 was without top drive, and so that the drill hole was not inoperative generating unproductive time, it had to be put into operation with the quadrant or kelly joint.
The other elements or components that can belong to this system, are all those that make the top drive rotate or in its defect the kelly joint or quadrant. When the top drive is in operation it spins the whole drill string and the drill bit, to get an idea of which components are spinning, let's follow the route of points in the image #1:
25] Drill string, the drill string is made up of the downhole assembly (BHA) which is made up of heavy tubing such as drill collars and heavy weight transition tubing, along with the bha is assembled the drill pipe which finally gives depth to the well. Here is a representative picture of the drill pipe:
The drill bits are connected to the first drill string, so it could be said that the drill bit also belongs to the downhole assembly (BHA), among the drill bits there are PDC, diamond, polycrystalline and tricone bits as the one shown in the following picture:
This system is very important in the operational activities of well drilling, because as we go deeper into the length of the well, more drill pipe is required, each time a drill pipe is added and connected, a stop must be made to connect the pin of the pipe to be connected to the pipe box that is already connected to the drill string. To perform this activity you need equipment that can lift (hoist) the drill pipe each time it is connected, not only that, but you also need to be able to lift and lower the drill string. In order to get to know the components that make up the lifting system, let's follow the route of points in image #1:
7] The winch is located on the two rear legs of the drill string, the main function of the drum or winch is to roll up and unroll the drill string.
14] The winch is practically the frame that supports practically all the components needed to drill an oil well. The winch provides the necessary height so that the drill string can be raised or lowered along with the traveling block. The more power the drill rig has, the larger the winch can be and the deeper the well can be.
12] Drill string, the drill string is the element that allows the hook and the traveling block to be held together with the top drive in order to raise or lower the drill string.
13] Crown block, the crown block is a pulley through which the drill string passes and serves to allow the link between the winch and the traveling block.
11] Hook or travelling block, the hook or travelling block allows the connection of the drill string to be raised or lowered together with other elements such as the top drive and all drill strings, so we could say that the top drive and the drill string that belong to the rotation system also belong to the lifting system.
The operational activities that are carried out in the drill rig, such as activating the winch so that the drill string can go up or down, activating the top drive so that the drill string can rotate, and activating the mud pumps among other components can be carried out thanks to the components that supply energy to the drill rig, without this energy it would not be possible to drill and build an oil well.
In addition to this, the site where the decision is made to drill an oil well is set up as a camp with trailers where supervisory personnel, engineers in charge of supervising operational activities in the drilling of wells, will spend the night.
The existing safety in the drill hole focused from the point of view of the safety system does not refer to the safety standards in the drill, that is another issue that can be addressed in another post.
When we refer to the safety system, we are referring to the existing components that fulfill the function to be able to close the well when necessary, many may wonder:
When is it necessary to shut down an oil well?
In some circumstances when an oil well is being drilled there may be an eventuality where the formation pressure (pressure at which fluids in the subsurface such as gas and/or oil are found) is greater than the pressure exerted by the formation fluid:
Formation pressure (reservoir pressure) > Drilling mud pressure
It turns out to be the necessary condition for these fluids (gas and/or oil) to migrate from the bottom of the well to the surface and cause a blowout, and that due to the friction generated by the drilling components it can cause a fire as shown in the following image:
There are drilling parameters that can vary suddenly, such as an unexpected slowing down of the drilling speed that can be detected by the driller on the drill floor, which can be an indication that an onslaught of fluids such as gas and/or oil is on its way migrating from the bottom of the well. This is the precise moment to close the well and then enter into effective well control using well control methods such as the driller's method or the engineer's method that I have explained previously in my thematic series dedicated to well control.
Now it is only possible to close the well by means of a set of safety valves called BOP valve assembly, this valve assembly has an arrangement in which you can see in the following image:
If we follow the point path of image #1, we can explain the valve assembly as follows:
23] Annular spherical BOP, the annular spherical BOP is the geometrically round shaped valve, this valve can open and close at any diameter of the drill pipe, so it is recommended that if the well is to be closed it should be done first with the annular spherical valve because it can close at any diameter of the drill pipe.
24] Pipe branch BOP and cutting branch BOP, these carts open and close at a specific diameter of the drill pipe. It is recommended to activate only the pipe branch BOP valve, because the other shut-off valve if activated will cut the drill pipe, thus losing the option to control the well, even today many BOP arrays do not contemplate the pipe branch BOP valve.
Conclusion and contribution
It is very important for operations involving drilling activities to be able to organize each of the components that are important for well drilling into systems that help organize these components into a less complex organization.
In the case of any university student who is practicing his or her studies in petroleum engineering it is important that he or she knows the components of a drilling rig and that he or she knows how to identify them within systems. Even in order to address the issues related to curricular units such as drilling I and drilling II it is important to develop each of the topics from the point of view of the systems that make up an oil well drilling rig.
For the development of the topics involved in drilling wells that can be addressed by me in future publications in the STEM order it is important that my reader friends and followers can understand the way in which the components of a drilling rig are organized, so that at the moment I find myself explaining any topic involved in drilling wells I know exactly in which system a certain topic is being explained.
It is a pleasure for me to work to provide the entire steemit.com community with an article summarizing the five systems that comprise most of the components and elements that make up the well drilling activity, so I hope it is of benefit and understanding to everyone.
I thank you in advance for the questions, suggestions and recommendations that you may express through the comments in this publication, all with the objective of establishing the healthy debate and interaction that is very typical of the communities that support the academic and engineering content within the steem platform, greetings and until a next delivery from your friend @carlos84