Abstract: A method for abandonment of a subsea well includes: setting a packer of a lower cementing tool against a bore of an inner casing hung from a subsea wellhead; fastening a pressure control assembly (PCA) to the subsea wellhead; hanging an upper cementing tool from the PCA and stabbing the upper cementing tool into a polished bore receptacle of the lower cementing tool; perforating a wall of the inner casing below the packer; perforating the inner casing wall above the packer by operating a perforator of the upper cementing tool; mixing a resin and a hardener to form a sealant; and pumping a fluid train through bores of the cementing tools and into an inner annulus formed between the inner casing and an outer casing hung from the subsea wellhead. The fluid train includes the sealant followed by a cement slurry.

Abstract: A method for sealing a well includes: placing an obstruction in a bore of an inner tubular string disposed in a wellbore; forming an opening through a wall of the inner tubular string above the obstruction; mixing a resin and a hardener to form a sealant; and squeezing the sealant into the bore, through the opening, and into an annulus formed between the inner tubular string and an outer tubular string, thereby repairing a cement sheath present in the annulus.

Abstract: A method for abandonment of a subsea well includes: setting a packer of a lower cementing tool against a bore of an inner casing hung from a subsea wellhead; fastening a pressure control assembly (PCA) to the subsea wellhead; hanging an upper cementing tool from the PCA and stabbing the upper cementing tool into a polished bore receptacle of the lower cementing tool; perforating a wall of the inner casing below the packer; perforating the inner casing wall above the packer by operating a perforator of the upper cementing tool; mixing a resin and a hardener to form a sealant; and pumping a fluid train through bores of the cementing tools and into an inner annulus formed between the inner casing and an outer casing hung from the subsea wellhead. The fluid train includes the sealant followed by a cement slurry.

Abstract: A method for sealing a well includes: placing an obstruction in a bore of an inner tubular string; forming an opening through a wall of the inner tubular string above the obstruction; mixing a resin and a hardener to form a sealant having a density greater than a density of fluid present in the bore and present in an annulus formed between the inner tubular string and an outer tubular string; and injecting the sealant into the annulus. The sealant falls down the annulus to the opening. A portion of the sealant is diverted through the opening and into the bore. The sealant cures to form a balanced plug in the annulus and the bore.

Abstract: A lightweight cross-linked gelled settable cement fluid system derived by pre-hydrating a water gelling agent, and then using that to mix with a cement blend which results in a very stable cement blend, which will matriculate through any fluid and not disperse, and form a cohesive plug wherever it comes to rest; wherein the fluid is injected at the bottom of the 10 pound/gal brine, and the fluid rises to the top of the brine where it reforms into a cohesive plug and hardens; and wherein the fluid can be applied to any density solution, and provide stability and cohesiveness to any settable plug; and wherein the cement/gelled water mixture is then cross-linked using standard hydraulic fracturing cross-linkers to provide a stable structure and ability to matriculate through another fluid and not disperse into that fluid.

Abstract: Embodiments of the present invention generally relate to a sealant for forming durable plugs in wells and method for completing or abandoning wells. In one embodiment, a method of plugging a wellbore includes mixing sealant; mixing cement; pumping the cement and sealant into the wellbore. The cement is above the sealant and the sealant cures to become viscoelastic or semisolid.

Abstract: A method of plugging wells wherein cementitious materials (like Portland cement) are formed into pellets that can be dumped or dropped into a well that is filled with an aqueous solution. The pellets will fall quickly to the bottom of the well or mechanically placed barrier, and over time, the pellets will loose their structure and release dry cementitious material into aqueous well fluid. The cementitious material will wet in the aqueous well fluid and then set to form an impermeable plug in the well.

Abstract: A pre-stressed annular sealant and method of creating a durable seal in a well bore annulus which is based on hydraulic cement that is designed to be easily pumped and placed into a casing-wellbore annulus, to set into a hardened mass, and to then undergo post-set crystal growth and phase changes in the crystalline matrix to combat inherent volumetric shrinkage and to create internally-generated compressive stress in the cement matrix. This internally-generated compressive pre-stressing compensates for tensile stress induced by well operations. The tensile stress must be greater in magnitude than the magnitude of the compressive pre-stress plus the magnitude of the cement's tensile strength before the cement sheath will fail in tension. This expansion and pre-stressing also creates significantly higher shear bond strengths than those developed with ordinary hydraulic cement.

Abstract: A thixotropic cement composition comprising water, hydraulic cement, a titanium chelate and a crosslinkable agent and methods of using same to combat migration of formation fluids in oil, gas and water wells are provided.

Abstract: Thixotropic cement composition comprising water, hydraulic cement, titanium chelates, and crosslinkable agents and methods of using same for sealing or cementing subterranean zones penetrated by a borehole are provided.