CALCULATION OF WELLHEAD PARTS

Wellhead rigidly connects the entire working column into a single system, takes the load arising from their weight, and transfers the entire load to the conductor. Provides insulation and tightness of the space between the columns, while at the same time allowing you to monitor the condition of the wellbore and perform the necessary technological operations. Wellhead serves as a pedestal for installing the production string lowered into the well. During drilling, blowout preventer equipment is installed on it, which is dismantled after drilling. The number of these elements depends on the number of working strings in the well. The casing head is positioned according to the sequence of running and cementing at the wellhead. They are selected during drilling taking into account the expected formation pressure after the drilled well interval. The operating conditions of the column head are quite difficult: In deep wells, the load from the weight of protective casings can exceed several hundred kilonewtons. The column head elements also absorb the pressure of the medium in contact with them. If there is H2S, CO2 in the formation fluid or gas, or if the formation water is highly mineralized, the casing is subject to corrosion. When the heating agent is injected in deep wells, their tubing head and casing head heat up to 150-250° C, and in the Northern conditions it cools down to -60° C. Violation of the reliability of the column head leads to serious accidents, and in some cases – fires and explosions In particular, the casing heads of multi-casing wells have a large mass and vertical size. Their high metal intensity and high demand require the expenditure of large amounts of steel, especially alloy steel, for their production. As the vertical size of the casing head increases, well maintenance becomes more complicated. Column heads for wellhead equipment are manufactured with different numbers of protective columns: three-, four- and five-post. The principle and design diagrams of such column heads are similar. Keywords: wellhead, casing hanger, equivalent tension, cylindrical part, flange.