Method for placing ball sealers onto casing perforations in a deviated portion of a wellbore
A method is described for plugging a known number of perforations in a well casing positioned in an intentionally deviated portion of a wellbore by means of ball sealers, each sized to restrict flow through the perforations, the method comprising: introducing into the casing a first fluid having a known density; introducing into the casing a number of ball sealers, each having a density less than the density of the first fluid, with the proviso that the number of ball sealers introduced into the casing is greater than or equal to the number N which satisfies the following relationship: N = P + D/sup 2//2.4 where P is the known number of the perforations to be plugged by the ball sealers, and D is a dimensionless number equivalent to the inner diameter of the casing in inches; and introducing into the casing a second fluid having a density less than the density of the ball sealers, the first and second fluids being immiscible and forming an interface between each other such that the ball sealers are transported down the casing at the interface between the first and second fluids and past the perforations to seal the known number of perforations.
- Assignee:
- Exxon Production Research Co., Houston, TX
- Patent Number(s):
- US 4753295
- OSTI ID:
- 6785211
- Resource Relation:
- Patent File Date: Filed date 30 Apr 1987
- Country of Publication:
- United States
- Language:
- English
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Method for placing ball sealers onto casing perforations