ABANDONMENT METHOD FOR WELL WITH GAS SHOW IN TUBING-CASING ANNULUS Russian patent published in 2007 - IPC E21B33/13 E21B43/12 C09K8/467 C09K8/473 

FIELD: oil and gas production industry, particularly methods or devices for cementing, for plugging holes, crevices, or the like, for instance abandonment of well drilled in permafrost zones.

SUBSTANCE: method involves killing well; removing production tubing; arranging cement bridge over production reservoir and in conductor shoe; filling well bore with non-freezing liquid within permafrost rock interval; dismantling production tree and landing head at well head; installing concrete column on well head; additionally arranging cement bridge in production string below leaking interval; leaving processing mix between additional cement bridge and cement bridge arranged over production reservoir; creating additional perforation orifices within production string leaking interval; injecting and forcing light-weight sealing composition in casing annulus, wherein forcing pressure is 0.7-0.8 of pressure created during production string and cement bridge arranged below leaking interval proof-testing; hardening the light-weight sealing composition; filling said additional perforation orifices with expanding cement mix; arranging cement bridge in conductor shoe after production string leakage elimination; filling well with non-freezing liquid within permafrost rock interval. The light-weight sealing composition includes Portland cement in amount of 15.0-16.0% by weight, epoxy polyurethane polymer in amount of 45.0-47.0% by weight, silica-alumina microspheres in amount of 1.2-2.7% by weight, filler - polyvinylchloride in amount of 18.0-18.5% by weight, latex in amount of 13.5-13.8% by weight, trimethylchlorosiloxane in amount of 0.1% by weight and hardener in amount of 5.4-5.5% by weight. Expanding Portland cement mix comprises plugging Portland cement in amount of 85-90% by weight, silica-alumina hollow microspheres in amount of 10-15% by weigh, hydrocarboaluminate additive in amount of 2-4% by weight, gypsum in amount of 2-4% by weight, plasticizer in amount of 0.2% by weight, remainder is water or 4% calcium chloride solution.

EFFECT: increased efficiency.

1 dwg