Search
Close this search box.

Introduction to BOP structure

Table of Contents

BOP stands for Blowout Preventer. The main role of BOP is to ensure the safe operation of coiled tubing equipment, prevent well fluid ejection, and protect the formation, personnel and equipment safety. BOP is basically not used in the normal operation of coiled tubing equipment, and the role of BOP is very important in the event of blowout and other accidents. BOP is generally installed at the wellhead, its specifications are mainly 2.56 “, 3.06 “, 4.06 “, 5.12 “, 7.06 “, the working pressure is generally 10K and 15K. At present, the commonly used BOP is 10K-3.06″,10K-4.06″, 10K-5.12″; 15K-4.06″, 15K-5.12”.

According to the number of ram, BOP can be divided into double ram BOP and four-ram BOP. At present, four-ram BOP is widely used, and each ram is fully sealed, shear ram, slip ram and half-sealed ram from top to bottom. The RAMS are used in pairs to complete the following functions:

① The full sealing ram can be used to seal the wellhead;

② The shear ram is used to cut the oil pipe in the well when an emergency occurs;

③ The slip ram is used to jam the tubing when the injector fails;

④ The half-sealing ram is used to seal the coiled tubing annulus;

The whole gate seal is divided into the gate outer seal and the whole gate inner seal. When the fully sealed ram is closed, the outer seal of the ram is sealed by the upper and lower pressure difference. When the pressure is applied from top to bottom, the gate outer seal does not work. The inner seal of the whole seal is connected with the ram body through the flat key, and it is easy to replace.

The outer seal of ram and the inner seal of full seal belong to BOP spare parts, and the inner seal of full seal and outer seal of ram should be inspected after each operation. If the rubber sealing surface is found damaged, it must be replaced. When the size of the tubing changes, the full seal ram is not affected and does not need to be replaced.

The shear ram is used to cut the oil pipe in the well when an emergency occurs. The shear blade belongs to the BOP spare part. After each operation, check the shear blade. If excessive wear is found, replace the shear blade.

Tubing centralizing device and slip are BOP spare parts. When the tubing size changes, it is necessary to equip the slip and centralizing device matching the tubing size. After each operation, the slips are inspected. If the slips are found to be damaged, they must be replaced.

The half-seal ram is used to seal the continuous pipe annulus, including the guide tubing. When the half seal is closed, the outer seal of the half seal is sealed by the upper and lower pressure difference. When the pressure acts from top to bottom, the half-sealed ram does not have a sealing effect, which is consistent with the outer sealing principle of the full-sealed ram. The half seal ram is connected with the ram body by the flat key, and it is easy to replace. Half gate outer seal, tubing centring device, half gate and half gate body are BOP spare parts. When the tubing size changes, all the other parts except the half gate outer seal need to be replaced.

There is an injection port between the BOP shear ram and the slip ram in the form of a flanged 2 “Fig1502 female nipple. This port is mainly used for pressure relief or emergency kill. The four-ram BOP is equipped with a balance valve block at each ram assembly, of which only the balance valve block at the sealed ram has a spool (also known as an equalizer pin valve). The balance valve block at the shear ram and slip ram is closed to allow for a variety of ram configurations. When the full seal gate and the half seal gate are closed, there is a pressure difference between the top and bottom of the gate. When the seal gate needs to be opened again, the upper and lower pressure needs to be balanced, otherwise it will cause damage to the gate or hydraulic assembly.

Facebook
Twitter
LinkedIn
Pinterest
Email

Leave a Reply

Your email address will not be published. Required fields are marked *

Subscribe To Our Newsletter

Get exclusive purchase tips,  petroleum equipment solutions that we don’t share anywhere else.