Resin Application as Permanent Well Barrier for Wells with Sustainable Casing Pressure in Sichuan

Abstract

This is to share the plan for the application of resin technology to seal off annulus sustained casing pressure and combine with cement plug as the permanent well barrier for the well(s) with sustainable casing pressure in Sichuan Basin, China. According to API RP 57 and Oil & Gas UK “Guidelines for the suspension and abandonment of wells”, the well barrier shall need at least 100 ft cement. For the legacy wells with sustained casing pressure, to comply with API standard, the gas source will thus be isolated and the well is secured by the cement plug(s) of 100 ft at the section milling window(s). This paper is to present the current plan with the resin technology application. It aims to apply the new technology of resin as the permanent well barrier for the shallow sweet gas section, which could help seal the micro-channels in the annular to mitigate casing pressure and establish reliable well barriers with superior mechanical properties. A lab test with low/high-temperature condition has been performed to examine the shrinkage, sour resistance, and the longevity of resin if it is used as a solid-free media to kill sustained casing pressure and part of the well barrier to isolate a shallow sweet gas zone, which requires much lesser section milling length compared to the conventional cement plug methodology. This could help minimize rig time, reduce the cost, mitigate the well integrity risk, and improve the safety and environmental protection for the local community.