Wellcem (Norway)

Abstract The challenge was with wells where the casing had lost its barrier/integrity because of casing leakage. There the result was that production wells were closed in. These problems are often caused by cementing failure when the well was drilled and cemented, lost zone, experienced corrosive formation fluid from the formation, treads leakage or other reasons for this integrity failure. There have been tried out serial methods for how this casing leakage can be repaired safely and in a cost-effective manner. Casing damage/leakage with low or non-injectivity have been squeezed and repaired with Thermal activated resin. Thermal activated resin is a nonreactive polymer with qualities that are resistant to all formation corrosives/hazard fluids. Thermal activated resin will reinstall a good well barrier and integrity to protect casing from future corrosion. Thermal activated resin has been used in serial wells in Saudi Arabia in both onshore and offshore fields. In a small volume, with a controlled setting and short operation time, a high success rate has been achieved. The solution to these challenges was developed by designing thermal activated resin casing repair liquid plug with a density equal from 64 pcf to 152 pcf. The setting time can also be adjusted accurately. This new treatment slurry was able to be bullheaded and displaced with polymer mud/brine at 64 pcf to 152 pcf. The slurry was easily able to be pumped through the drill pipe. This novel product possesses low elastic modulus and high flexibility in density, viscosity and fast setting time according to requirements. The well barrier elements made of this product have no risk of shrinking, cracking, gas channeling or deterioration upon exposure to harsh reservoir environments. This paper presents a case history and field application of this novel polymer based casing repair material for successful treatment of full losses or when there is no/low injectivity in formations in most of the critical oil and gas fields in Saudi Arabia. Also, the paper includes a discussion of the methodology, material properties and applications.

Abstract Assured well integrity and the reduction of associated drilling problems has been a recurrent challenge for operators over the years. Conventional cement does not always endure the mechanical stresses and requirements placed on it by a wellbore and it often falls short in providing permanent isolation beyond the production life of a well. Unconventional alternatives, such as thermosetting resins, are now available and can be used to solve a variety of drilling and production barrier problems, filling the niche where conventional methods have failed. The plugging and abandonment of oil and gas wells along with their associated depleted reservoirs is now an urgent matter whose antiquated methodologies are in need revision. Many previously abandoned wells are now leaking due to cement failure. As a result, many operators seek to employ alternative materials that are more resilient and reliable when permanently abandoning a well. However, as quite often is the case in all facets of industry, the introduction of new technology faces speculation and must overcome a variety of administrative controls before being adopted and implemented into the field. As a result, intensive effort is being spent on research to further validate the technical viability of polymer resins and advocate industry progression in this novel direction. This paper explores the benefits of resin application for plug and abandonment operations in place of conventional systems from a methodological and laboratory perspective.