Offshore platform is a structure that provides production and living facilities for drilling, oil production, container transportation, observation, navigation, construction and other activities at sea. According to its structural characteristics and working state, it can be divided into three categories: fixed type, movable type and semi-fixed type.
The lower part of the fixed platform is directly supported and fixed on the seabed by piles, enlarged footings or other structures. The movable platform floats in the water or is supported on the seabed, and can be displaced from one well to another. In recent years, novel semi-fixed marine platforms are being studied, which can be fixed in deep water and can be moved, such as tension-leg platforms.
Offshore oil recovery platforms are mainly used to extract oil and gas and perform preliminary treatment of oil and gas (such as oil and gas, oil-water separation). It is the basis of production wells and oil and gas processing facilities. Therefore, there is a corresponding deck area and load capacity, but the displacement limit is not as strict as that of a drilling platform. Due to the special use environment, there are great differences between offshore wellhead devices and land wellhead devices in terms of structure and performance requirements.
The tubing head is a device component that connects the uppermost casing head and the oil (gas) tree to suspend the tubing and seal the annular space between the tubing and the casing. The tubing head is located above the casing head, including the tubing head spool and the tubing hanger. Its function is to suspend the tubing, downhole tools and seal the annular space of the oil casing.
The VR plug r/r tool is a special tool for plugging the wing of the spool when replacing the wing valve of the tubing head in the oil field production wellhead. Due to space constraints, the well positions of the offshore platform are densely arranged, resulting in the limited space between production wellheads. Due to the influence of the high platform deck and platform support columns, the surrounding space of the oil production wellhead is further compressed.
When the wing valve of the tubing head leaks, the traditional VR plug r/r tools are affected with its own structure and the limitation of the offshore platform space, so the installation cannot be completed. And the replacement of the side outlet valve of the tubing head cannot be successfully completed, which has a huge impact on the safety, environmental protection and efficiency of offshore oilfield production.
Therefore, Sanjack has developed a retractable VR plug r/r tool, which can replace the side outlet valve of tubing head in the narrow space such as offshore platforms.
The R/R tool consists of 1-handle, 2-transmission rod, 3-A bearing, 4-A locking screw, 5-A sealing ring, 6-A bearing box, 7-rotating sleeve, 8-transmission sleeve, 9-B Bearing box, 10-B bearing, 11-B locking screw, 12-B sealing ring, 13 connecting flange, 14 bleed screw, 15-check valve, 16-pressure gauge, 17-positioning pin, 18-stop, 19-buffer spring, 20-sliding pin, 21- struck, 22-connector, 23-rotating sleeve pressure balance hole, 24-drive sleeve pressure balance hole, etc.
Working principle: There is a transmission sleeve on the outer circumference of the transmission rod, and a buffer spring is installed in the transmission sleeve.
The buffer spring is positioned by the stopper and fixed by a positioning pin; the outer circumference of the transmission sleeve is equipped with a rotating sleeve which is installed in the hole of the connecting flange , The rotating sleeve has B bearings which helps rotating sleeve fix on the connecting flange.
The rotating sleeve and the connecting flange are sealed by a B sealing ring; the transmission rod, the transmission sleeve, and the rotation sleeve form a two-stage rotating mechanism, and the transmission rod and the transmission sleeve work together by thread to make transmission sleeve into rotating sleeve, thereby greatly reducing the overall length of the tool and save space.。
The retractable VR plugr/r tool designed by Sanjack has a compact structure and is especially suitable for replacing the side outlet valve of the tubing head in the occasions with narrow space such as offshore platforms.