Plugging methods for large-volume wireline cement bailer

摘要

Hydrocarbon wells have limited life spans and after well depletion, plug and abandonment procedures are required to safely seal the well. This disclosure describes an apparatus and methods for using a large-volume wireline deployed bailer tool (herein referred to as "tool") to plug a depleted well. Figure 1 and Figure 2 illustrate two methods for generating a plug with a tool deployed on a wireline. As shown in Figure 1, the production tubing is perforated directly above a fundament for supporting the plug in the production tubing and A-annulus. The tool is then positioned in the wellbore to introduce cement into the A-annulus through the perforations by overpressure. In an example, the tool may be latched or stung into a landing packer during release of the cement. Preferably, the landing packer comprises a check valve to prevent cement u-tubing back into the production tubing above the landing packer. Afterwards, the tool car be un-latched or un-stung from the landing packer and retracted from the well. The lower end of the tool can be closed by one-way valves which prevent re-entry of expelled cement, and which also only open to expel cement above a pre-set threshold pressure. Additionally or alternatively, a seal can be provided at the lower end of the tool which bursts under a pre-set threshold pressure or after being punctured by a sharp object which can be provided on the landing packer or fundament.