Tool Introduction

The full bore multifunction valve is an annular pressure operated valve used for casing wells. It can be used as a compensating valve or a back pressure valve, with both upper and lower pressure responsive multifunctional valves operating simultaneously, with a buffer chamber for travel. Before fracturing operations and flow testing, this shock wave helps clean up the debris generated by perforation. When the two multifunctional valves on the tubing string are separated to form an atmospheric chamber, sudden pressure fluctuations may occur. When the bottom ball valve opens, the solid forcefully pushed into the perforation will be blown into the atmospheric chamber.

Structural characteristics

① No column operation;

② Due to the rapid opening of the ball valve, more effective pulses can be obtained;

③ Generate the required atmospheric chamber capacity by leaving a gap between the valves;

④ Allow for circulation or observation of well flow after flushing is completed;

⑤ Allow oil pipe operations to pass through the full bore diameter.

Operation:

When the pressure responsive multifunction valve is lowered into the well, the ball valve is in the closed position and the atmosphere is trapped between the multifunction valves. The lower valve is opened by the operating piston, with one side exposed to the annular pressure at the top of the packer and the other side exposed to the annular pressure at the bottom of the packer.

After the packer seat is sealed, the annular pressure is applied to move the piston downwards to pull the steel ball into the open position. Lock the claw into a slot to keep the ball in the fully open position.

As long as the oil pipe pressure is equal to or greater than the annulus pressure, the upper valve remains closed when operating the lower valve.

Before the upper valve is opened, release the oil pipe pressure while keeping the annular pressure constant. The pressure responsive multifunction valve above also includes a locking claw to lock the steel ball in the fully open position. After the valve is opened, the unsealing cycle of the packer begins.

The opening pressure is controlled by the shear pin, and the operating pressure can be increased or decreased by adjusting the type and quantity of shear pins.

technical parameter