What are the general steps of drilling construction
What are the general steps of drilling construction? To drill an oil and gas well, due to different factors such as drilling depth, geological hardness, pressure, and well process requirements, the construction period varies from ten days to more than one year. The drilling process is also quite complicated. , We only discuss the more important key.
1. Lower sleeve:
Casing design can be said to be the highlight of drilling. Any well will often encounter several different geology, depths or emergencies, production and development needs during the drilling process, so it needs several layers of casing to protect the well hole in order to go smoothly. Drill into the target.
A borehole is drilled from a borehole to a certain stratum depth or level, and then the next layer of casing is drilled with a smaller size drill bit. Take Well 141 as an example, the first phase is 171/2" After the drill bit has drilled to 1,500 meters, the 133/8" surface pipe sleeve is lowered first, and then only a 121/4" drill bit can be used to drill... etc.
2. Drilling out and drilling down:
In order to replace a blunt bit, or prepare a core sample, repair equipment, or plan to do other work in the well, it is necessary to lift the drill and the bit to the ground, and then remove the blunt old bit and connect it to the new one. Select the new drill bit, and follow the reverse order of the trip, and then go down to the bottom of the original well to start drilling.
The deeper the drilling, the more time it takes to trip and drill, and the actual drilling time is relatively reduced.Therefore, how to choose a good drill to increase the progress of drilling, reduce the number of trips and shorten the construction period, is also the responsibility of the engineer.
3. Mud and drilling:
With the development of the oil well drilling industry, drilling is also going deeper. In addition to the important task of removing cuttings, the mud must have other functions to complete the drilling operations of deep wells and difficult wells.
The mud can not only clear the well hole, cool the drill bit, circulate the drilled cuttings, improve the drilling rate, but also form a mud wall on the inner wall of the well hole to temporarily protect the well hole and prevent it from collapsing. Adding barite powder can also increase the specific gravity of the mud to resist the pressure of the formation to prevent collapse and prevent formation fluids from intruding into the well bore. In case of leakage of mud, plugging materials can also be added to the mud to stabilize the well; and mud The viscosity of the slurry can suspend drill cuttings and prevent the borehole from being buried, so the mud has many functions.
Mud is as important to drilling as blood is to the human body. It will directly affect the success or failure of the drilling project. Therefore, how to balance the various properties of the mud and choose the appropriate mud is the test of the team leader and the mud crew. .
