Rigless Zonal Isolation in High-Permeability and Low-Pressure Sandstone Formations Using an Organically Crosslinked Polymer Sealant: Successful Field Application

Abstract

This paper describes a rigless and cost-effective field implementation of conformance polymer sealant (CPS) and particulate-CPS (P-CPS) systems used successfully in high-permeability and low-pressure reservoirs for zonal isolation intervention. The CPS system is an organically crosslinked polymer that is thermally activated to effectively seal the targeted interval. The P-CPS system combines the CPS system with particulates that provide leakoff control to help ensure shallow matrix penetration of the sealant. The traditional method for zonal isolation consists of rig intervention for cement squeeze, which can be time-consuming and expensive. In high-permeability and low-pressure reservoirs, several unsuccessful attempts can extend the intervention by two or more weeks. CPS and P-CPS systems provide a predictable and controllable right-angle set time that can help to ensure sealing on the first attempt. These systems do not develop compressive strength, simplifying the cleanup stage by quickly and easily jetting it out of the wellbore with coiled tubing (CT), as opposed to cement that must be drilled/milled out. This paper describes laboratory evaluations, treatment design methodologies, and two case histories from Kuwait, including one well that produced 1,600 BOPD after reperforations.