Zonal isolation of a subterranean wellbore
AssigneeSaudi Arabian Oil Company
InventorsSaad Hamid, Scott Fraser Ashby
Life of this patent
Estimating the term…
Abstract
A plug assembly used in a wellbore fracturing process includes an annular housing that is set in the wellbore, and a ball that lands and seats in the housing. The housing and ball form a pressure barrier in the wellbore that isolates one portion of the wellbore from an adjacent portion. Pressurizing the portion of the wellbore isolated by the plug assembly generates fractures in a formation around that portion of the wellbore. The ball is not reactive with wellbore fluid or affected by wellbore conditions. Fluid communication across the plug assembly is reestablished by fracturing or milling the ball within the housing. Wellbore operations are conducted by inserting downhole tools through a bore axially formed in the housing.
Claims18
A method of wellbore operations comprising:
- setting an annular housing within a wellbore;
- sealing an annulus between the housing and sidewalls of the wellbore;
- landing a ball on the housing that blocks pressure communication through a bore axially formed through the housing;
- generating fractures in a formation that circumscribes the wellbore by pressurizing a portion of the wellbore uphole of the ball;
- providing pressure communication through the bore in the housing by fragmenting the ball;
- after landing the ball on the housing and prior to generating the fractures, inserting a tubular member into a main bore of a wellhead assembly that is disposed at an opening of the wellbore to isolate the main bore from the wellbore;
- and
- inserting a downhole tool through the bore in the housing.
A method of wellbore operations comprising:
- setting a plug assembly at a designated depth within a wellbore;
- using a ball to block pressure communication across the plug assembly;
- isolating a main bore of a wellhead assembly that is mounted over the wellbore by inserting a tubular member into the main bore;
- breaking the ball into fragments that pass through a bore in the plug assembly;
- and
- inserting a downhole string through the bore in the plug assembly.
A method of wellbore operations comprising:
- providing a plug assembly having a bore with an inner diameter of about 3 inches to about 3.75 inches;
- setting the plug assembly within a wellbore that is lined with casing having an inner diameter that ranges from about 3.9 inches to about 4.7 inches;
- providing a ball having an outer diameter of about 3.25 inches to about 4 inches;
- landing the ball on the plug assembly;
- fracturing a formation circumscribing the wellbore with pressurized fluid that urges the ball against the plug assembly;
- isolating a wellhead assembly at an opening of the wellbore from the pressurized fluid by inserting a sleeve into a main bore of the wellhead assembly after landing the ball on the plug assembly and prior to fracturing the formation;
- fragmenting the ball with a downhole string;
- and
- inserting the downhole string through the bore in the plug assembly.
Dependencies are inferred from the claim text.