Backpressure Ball

摘要

A process for plugging a wellbore, e.g., an oil or gas well, which comprises installing a backpressure ball device into the wellbore to increase the back pressure for better control when introducing cement or other liquid plugging medium to plug the wellbore. The device has a spherical shape with through bores and/or external channels in a geometric pattern. The external diameter of the sphere provides a shoulder of given diameter which, when the device is installed in a wellbore, comes to rest against a smaller diameter shoulder within the wellbore. The device may free fall for all or part of the way down the wellbore but is typically pumped down at least for the last part of its delivery to confirm by an increase in pump pressure that it has landed. Cement and other liquid may then be pumped through the backpressure ball device to the distal region of the well. The backpressure ball device may also be applicable for use in the operation of an oilfield by providing backpressure to actuate drive rods.

主权项

1. A process for plugging a wellbore, wherein the process comprises the steps of:
a) installing a spherical backpressure ball device in the wellbore, wherein the backpressure ball device has through bores with a predetermined diameter in a geometric pattern, or external channels with a predetermined flow cross-sections in a geometric pattern, or both through bores and external channels in a geometric pattern; and b) injecting a settable medium into the wellbore and pumping it downhole to effectively seal off the wellbore cross-section.