Abstract
Horizontal wells are a regular feature of many oil and gas fields and pose different challenges to their vertical counterparts for the entire well life-cycle. A regularly overlooked element during well completion design is the preparation for ease of abandonment. Horizontal wells are often completed with slotted liners/gravel packs and in a toe-up configuration, and if required, the abandonment of these production sections can be a risky operation using standard abandonment tools and techniques.
This paper describes the execution and lessons learned of several horizontal well abandonment operations, including a novel abandonment procedure that overcomes many of the limitations of conventional abandonment procedures in the toe-up horizontal configuration. This novel technique involves the installation of tubing in the horizontal slotted liner, placing cement along the horizontal liner from the tip of the toe via an initial circulation operation, then subsequent perforation and packer squeeze operations to remediate any gaps in cement isolation.
The paper also shares the details of a recent completion design change implemented on several horizontal wells with slotted liners to enable simpler abandonments in the future. The completion change involves the installation of a series of blank pipe sections with swellable packers along the horizontal liner section. These sections will be used in the future to enable simple low-cost and effective cement squeeze procedures with coiled tubing units utilizing cement retainers or packers.
The novel procedure and completion changes described have become a new toolset for the safe and efficient abandonment of toe-up horizontal wells.
