The ram blowout preventer is a key part of the well control device. Its main purpose is to control the wellhead pressure during well repair, oil testing and maintenance operations, effectively preventing blowout accidents and achieving safe construction. Specific can complete the following operations:
(1) When there is a pipe in the well, matching the corresponding specification of the gate can close the annular space between the casing and the oil pipe column;
(2) When there is no tubing in the well, fully enclosed rams can be used to fully close the wellbore;
(3) In the case of closed wells, liquid circulation, throttling, injection, killing, well washing, etc. are performed in the wellbore by killing wells and throttling manifolds connected to the outlets on the side of the four-way circulation;
(4) Used in conjunction with throttling manifolds and killing manifolds to control bottomhole pressures and achieve near-balanced workover.
The ram preventer is divided into a hydraulic ram preventer and a manual ram blowout preventer according to the control method. The ram preventer is divided into a single ram preventer, a double ram blowout preventer, and a triple ram blowout preventer according to the number of rams. Device.
1. Hydraulic ram preventer
In general, manual ram blowout preventers can only be used to prevent blowouts, but not blowouts. When the injection pressure at the wellhead reaches 5 MPa or more, it is impossible to close the gate with a person rotating the screw, and it can only be operated remotely with a hydraulic blowout preventer and quickly shut off within a few seconds. The use of hydraulic blowout preventer must be equipped with corresponding hydraulic controls, high pressure hoses and quick connectors.
The BOP is divided into three types: circular, rectangular and elliptical. (1) Advantages of circular cavity: The stress state is reasonable and the processing technology is good; Disadvantages: high height, high quality, poor sealing performance. (2) Rectangular cavity (usually used for cast steel shells) Advantages: low height, good sealing; Disadvantages: poor cast steel shell material, defects such as pores and trachoma, four corners have stress concentration points, low compressive strength . (3) Oval cavity (usually used for forging part blowout preventer) Advantages: low height, reasonable stress condition, light weight, good sealing, Disadvantages: difficult to process. BOP is divided into upper and lower connection types: upper and lower flange type, upper wire lower flange type, upper flange lower wire type, upper and lower wire type, upper and lower clamp type, threaded connection type, and live head type. Which link type to use depends on the actual situation at the site. BOP shell according to the material, there are two kinds of cast steel and forged steel, and its material should comply with the provisions of national standards.
The fluid paths of hydraulic blowout preventers are generally built-in oil lines to prevent damage; exposed oil lines have basically been eliminated. Side door opening method of hydraulic blowout preventer: there are hinge seat type, non-hinged seat type and cylinder hydraulic opening type.