In order to investigate the problem of long-term strength retrogression in oil well cement systems exposed to high pressure and high temperature(HPHT)curing conditions,various influencing factors,including cement sour...In order to investigate the problem of long-term strength retrogression in oil well cement systems exposed to high pressure and high temperature(HPHT)curing conditions,various influencing factors,including cement sources,particle sizes of silica flour,and additions of silica fume,alumina,colloidal iron oxide and nano-graphene,were investigated.To simulate the environment of cementing geothermal wells and deep wells,cement slurries were directly cured at 50 MPa and 200?C.Mineral compositions(as determined by X-ray diffraction Rietveld refinement),water permeability,compressive strength and Young’s modulus were used to evaluate the qualities of the set cement.Short-term curing(2e30 d)test results indicated that the adoption of 6 m m ultrafine crystalline silica played the most important role in stabilizing the mechanical properties of oil well cement systems,while the addition of silica fume had a detrimental effect on strength stability.Long-term curing(2e180 d)test results indicated that nano-graphene could stabilize the Young’s modulus of oil well cement systems.However,none of the ad-mixtures studied here can completely prevent the strength retrogression phenomenon due to their inability to stop the conversion of amorphous to crystalline phases.展开更多
The emerging nanoscience,nanotechnology and nanomaterials can be used for various industrial applications to enhance reliability,performance,stability and functional capability.Their application in the design and deve...The emerging nanoscience,nanotechnology and nanomaterials can be used for various industrial applications to enhance reliability,performance,stability and functional capability.Their application in the design and development of tools and materials used in oil and gas industry for extreme drilling conditions could overcome the current limitations of conventional tools and the various fluid systems used by the industry.The functional limitations such as poor physio-chemical stability in acid gas environment,frequent mechanical failure and malfunctioning in complex geological environment,thermal degradation in high temperature environment,etc.of currently used conventional tools and fluid systems are associated with extreme operating conditions due to a shift of the drilling operation from low risk to high risk geological environments,onshore to offshore locations,shallow water to deep water environment,etc.The progressive shift to increasingly higher risk operating environments is unavoidable as the energy demand of global community has increased manifold and is expected to increase further in future.Moreover,the probability and likelihood of finding easy oils and gas resources in low risk areas are diminishing quickly.That is why the oil and gas companies are constantly shifting to extremely challenging environments to meet the global energy demand.This is reflected by the expansion of drilling activities in complex geological areas,deep water environments,extreme-HPHT environments,etc.As the current tools and equipment and also the additives and chemicals often fail and/or lose their functional ability due to the detrimental effect of exposure of extremely harsh conditions,the industry needs tools and equipment,chemicals fluid additives that are highly reliable,chemically resistive,thermally and mechanically stable to ensure safe and trouble free drilling operations.It has been demonstrated in several fields of study that nanostructured materials and additives exhibit improved mechanical,chemical,thermal,electric展开更多
The global oil and gas industry has a long standing initiative to develop and use the most environment friendly solutions in the exploration and exploitation of oil and gas resources to prevent any damage or degradati...The global oil and gas industry has a long standing initiative to develop and use the most environment friendly solutions in the exploration and exploitation of oil and gas resources to prevent any damage or degradation of other marine and terrestrial resources. This is reflected by increasing research in academics, research institutes and organizations around the globe to develop better and more environment friendly base fluids, viscosifiers, fluid loss additives, emulsifiers, lubricants, etc. to protect the local, regional and global environments, eco-systems, habitats and also the OHS of workers and professionals working in the oil and gas industry. This paper describes the development, testing and evaluation of several novel additives to demonstrate their suitability for oil and gas field applications to avoid any negative impact to the surrounding environment. Experimental results indicate that the newly developed additives provide desirable, similar or better performance with respect to conventional additives used by the industry and thus demonstrate their suitability for application in aqueous and non-aqueous fluid design. The plant-based organic additive identified to use as an ecofriendly viscosifier for aqueous mud system can also control the fluid loss behavior of clay free system and thus can act as a bi-functional additive. Several waste vegetable oil-based eco-friendly additives have been developed for their application as spotting fluids, base oil and emulsifiers for invert emulsion oil based mud. These additives have similar or better technical performance than the equivalents and the eco-friendly nature of the mud additives demonstrates their ability to perform the functional tasks with better protection of the surrounding environments.展开更多
基金Financial support comes from China National Natural Science Foundation(Grant No.51974352)as well as from China University of Petroleum(East China)(Grant Nos.2018000025 and 2019000011)。
文摘In order to investigate the problem of long-term strength retrogression in oil well cement systems exposed to high pressure and high temperature(HPHT)curing conditions,various influencing factors,including cement sources,particle sizes of silica flour,and additions of silica fume,alumina,colloidal iron oxide and nano-graphene,were investigated.To simulate the environment of cementing geothermal wells and deep wells,cement slurries were directly cured at 50 MPa and 200?C.Mineral compositions(as determined by X-ray diffraction Rietveld refinement),water permeability,compressive strength and Young’s modulus were used to evaluate the qualities of the set cement.Short-term curing(2e30 d)test results indicated that the adoption of 6 m m ultrafine crystalline silica played the most important role in stabilizing the mechanical properties of oil well cement systems,while the addition of silica fume had a detrimental effect on strength stability.Long-term curing(2e180 d)test results indicated that nano-graphene could stabilize the Young’s modulus of oil well cement systems.However,none of the ad-mixtures studied here can completely prevent the strength retrogression phenomenon due to their inability to stop the conversion of amorphous to crystalline phases.
文摘The emerging nanoscience,nanotechnology and nanomaterials can be used for various industrial applications to enhance reliability,performance,stability and functional capability.Their application in the design and development of tools and materials used in oil and gas industry for extreme drilling conditions could overcome the current limitations of conventional tools and the various fluid systems used by the industry.The functional limitations such as poor physio-chemical stability in acid gas environment,frequent mechanical failure and malfunctioning in complex geological environment,thermal degradation in high temperature environment,etc.of currently used conventional tools and fluid systems are associated with extreme operating conditions due to a shift of the drilling operation from low risk to high risk geological environments,onshore to offshore locations,shallow water to deep water environment,etc.The progressive shift to increasingly higher risk operating environments is unavoidable as the energy demand of global community has increased manifold and is expected to increase further in future.Moreover,the probability and likelihood of finding easy oils and gas resources in low risk areas are diminishing quickly.That is why the oil and gas companies are constantly shifting to extremely challenging environments to meet the global energy demand.This is reflected by the expansion of drilling activities in complex geological areas,deep water environments,extreme-HPHT environments,etc.As the current tools and equipment and also the additives and chemicals often fail and/or lose their functional ability due to the detrimental effect of exposure of extremely harsh conditions,the industry needs tools and equipment,chemicals fluid additives that are highly reliable,chemically resistive,thermally and mechanically stable to ensure safe and trouble free drilling operations.It has been demonstrated in several fields of study that nanostructured materials and additives exhibit improved mechanical,chemical,thermal,electric
文摘The global oil and gas industry has a long standing initiative to develop and use the most environment friendly solutions in the exploration and exploitation of oil and gas resources to prevent any damage or degradation of other marine and terrestrial resources. This is reflected by increasing research in academics, research institutes and organizations around the globe to develop better and more environment friendly base fluids, viscosifiers, fluid loss additives, emulsifiers, lubricants, etc. to protect the local, regional and global environments, eco-systems, habitats and also the OHS of workers and professionals working in the oil and gas industry. This paper describes the development, testing and evaluation of several novel additives to demonstrate their suitability for oil and gas field applications to avoid any negative impact to the surrounding environment. Experimental results indicate that the newly developed additives provide desirable, similar or better performance with respect to conventional additives used by the industry and thus demonstrate their suitability for application in aqueous and non-aqueous fluid design. The plant-based organic additive identified to use as an ecofriendly viscosifier for aqueous mud system can also control the fluid loss behavior of clay free system and thus can act as a bi-functional additive. Several waste vegetable oil-based eco-friendly additives have been developed for their application as spotting fluids, base oil and emulsifiers for invert emulsion oil based mud. These additives have similar or better technical performance than the equivalents and the eco-friendly nature of the mud additives demonstrates their ability to perform the functional tasks with better protection of the surrounding environments.
