Workover rigs are usually vehicle mounted, with a mast installed at the rear of the vehicle.

To facilitate the movement of the traveling block, the wellbore has a tilt angle of 3-5 ° towards the wellhead.

Under hook load, this tilt angle will generate a backward overturning force that causes the wellbore and even the entire vehicle to tilt.

In addition, the wellhead will also withstand wind loads during operation.

To ensure that the wellhead can stand stably in working condition, it is necessary to equip a guy-wire safety device.

On a traditional workover rig, the wire safety device usually consists of two internal load guy wires, four wind load guy wires, and two stable guy wires on the second-floor platform Two internal load tension guy wires are pulled between the top of the wellhead and the front end of the frame to balance the overturning force generated by the inclination of the wellhead;

Four wind loaded  guy-wires and two stable guy wires are on the second-floor platform, with their upper ends set on the top of the mast and the second-floor platform respectively, and their lower ends connected to corresponding anchor piles scattered on the ground to resist wind loads and strengthen the stability of the main engine.

Before the workover operation, six anchor pits should be dug according to the terrain of the well site to fix the wind load guy guy-wire and the stable guy guy-wire of the second-floor platform. In the excavated anchor pits, fill materials and cement should be used to fix the anchor piles.

For swamps, deserts, hilly areas, and well sites with very dense wellheads, there is no condition to anchor piles on the ground. Only cranes and flatbed trucks can be used to lift a large amount of cement blocks to replace anchor piles.

After workover operation, the anchor pit should be cleaned, and all cement blocks and fillers should be removed. The soil should be backfilled, or the cement blocks used to replace anchor piles should be transported away.

This type of workover rig has the following problems:

1. The guy-wire anchor pit expands the oil well operation area, which is often limited by natural conditions and has destructive effects on the environment;

2. Preparation before homework and cleaning after homework are time-consuming and laborious;

3. The position of the anchor pit is determined by the terrain, so it is necessary to fix and adjust the tension guy-wire every time, which is time-consuming and laborious;

4. The length of the tensioning guy wire is determined by the position of the anchor pit, and the force on each guy wire is uneven. When subjected to heavy hook loads, there is a risk of excessive eccentric loading or even overall overturning of the mast.

Sanjack developed a self-tightening rope type workover rig, which includes a vehicle mounted host, base, wellhead foundation, drilling platform, and rope safety device. When in operation, the base, wellhead foundation, and drilling platform are connected to the ground in sequence.

The vehicle mounted host is placed on the base, and the erected wellhead is connected to the wellhead foundation.

The rope is symmetrically arranged between the two sides of the upper body of the wellhead and the two sides of the front end of the frame, and between the two sides of the lower body of the wellhead and the two sides of the front end of the frame .

Between the two sides of the upper body of the wellhead and the foundation of the wellhead, between the two sides of the lower body of the wellhead and the foundation of the wellhead, between the two sides of the upper body of the wellhead and the foundation of the drilling platform, and between the two sides of the second floor and the foundation of the drilling platform o the workover rig with guy-line .

Before operating the self-tightening wire Workover rig, the water tank that has stored enough water can be placed as a counterweight on the base in front of the vehicle mounted host. The upper end of the tensioning rope can be installed at the corresponding positions of the upper body, lower body, and second floor of the derrick (or fixed as a dead end).

After the derrick is erected and the wellhead is aligned, the lower end of each tensioning rope can be locked onto the tensioning rope fixing seat set on the foundation of the carrier,the derrick, and drilling platform base, pre-tighten each tension rope according to the requirements. After workover completed, remove the upper and lower ends (or only the lower end) of each guy rope, lower the derrick, and the self-tightening wire Workover rig can be transferred.