Drilling an oil and gas well, due to drilling depth, geological hard and soft, pressure, well course seeking and other factors, the construction period from ten days to more than one year.
Drilling is also quite complex, and we'll talk only about the more important keys.
1, the lower tube sleeve The tube sleeve design can be said to be the main play of drilling.
Any well in the drilling process often encountered several different geological, depth or sudden conditions, production and development needs, so it is necessary to several layers of casing to protect the well, in order to successfully drill into the target drilling. The drilling well is drilled into a layer depth or level by the well, the next layer of casing sleeve, and then changed to a smaller size drill drill drill drilling. Take the pit 141 well as an example, the first phase with 171?2" drill drill drill to 1,500 meters, first down 133/8" After the surface casing sleeve, can only use 121/4" drill drill into ...
and so on.
2, start drilling, drill down
In order to replace the blunted drill bit, or prepare to take core samples, repair equipment, and intend to do other work in the well, you need to raise the drill with the drill bit to the ground, and then will use the blunt old drill bit to remove, and then pick up the new selected drill bit, and according to the opposite order of drilling, and then down to the original well bottom to open the drilling.
Drilling deeper, drilling time, the real drilling time is relatively reduced, so how to choose a good drill bit to increase the progress of drilling, reduce the number of drilling, shorten the construction period, is also the responsibility of the engineer far away.
3, mud and drilling The biggest feature of rotary drilling method is the use of mud as a circulating fluid in the well, the first use of the fluid in the drilling is "water", as far back as the ancient Egyptian era, the Egyptians in the quarry in a manual way to rotate the drill drill drill drill 20 feet deep hole, will use water to remove rock debris. China's Zhou Dynasty (more than 1,100 years ago), in Sichuan area drilling salt wells, but also with water to remove rock debris. Water, arguably the first "mud" used to drill. Until now, water was the main component of mud.
Especially in the low proportion of mud, water accounts for more than 85 percent of the total composition. With the development of the oil well drilling industry, drilling is also deep drilling.
In addition to the mud still plays an important role in removing rock debris, it must have a variety of other functions to complete deep and difficult well drilling operations. Mud can not only clear the well hole, cooling drill bit, cycle out of the broken rock debris, improve the drilling rate, but also in the well hole wall to form a mud wall, in order to temporarily protect the well hole, so that he can not collapse. If heavy crystal powder is added to the mud, the proportion of the mud can be increased to resist the pressure of the formation to prevent collapse and prevent the formation fluid from entering the wellbore.
In case of leakage mud layer, you can also add leak-blocking material to the mud to stabilize the well hole, and the viscosity of the mud is more suspendable drill chips, so that the well hole is not buried, so the function of the mud is many. The importance of mud to drilling, such as blood to the human body, will directly affect the success or failure of drilling works, so how to achieve a balance in the nature of mud, and choose the appropriate mud, is the engineering team site captain and mud personnel the biggest test.