Well integrity technology can effectively ensure the safety of the entire life cycle of oil and gas wells. With the exploration and development of more and more high-temperature, high-pressure, high-yield and deep wel...Well integrity technology can effectively ensure the safety of the entire life cycle of oil and gas wells. With the exploration and development of more and more high-temperature, high-pressure, high-yield and deep wells, and the constantly increasing requirements for safety and environmental protection in various countries, well integrity technology has become a research hot spot in the oil industry. Based on the analysis of the four basic concepts of well integrity: full life cycle, well integrity management system, well barrier, and risk assessment, this article conducts a comparative analysis of the development history of well integrity technologies at home and abroad, and systematically summarizes foreign wells. The current status of integrity technology, based on the above investigation and analysis, puts forward suggestions for the next development direction of well integrity technology, which has certain guiding significance for the development of the integrity of the next step.展开更多
Formation pressure is the key parameter for the analysis of wellbore safety.With increasing drilling depth,how-ever,the behavior of this variable becomes increasingly complex.In this work,a 3D model of the formation p...Formation pressure is the key parameter for the analysis of wellbore safety.With increasing drilling depth,how-ever,the behavior of this variable becomes increasingly complex.In this work,a 3D model of the formation pres-sure under uncertainty is presented.Moreover a relevant algorithm is elaborated.First,the logging data of regional key drilling wells are collected and a one-dimensional formation pressure profile along the well depth is determined.Then,a 3D model of regional formation pressure of the hierarchical group layer is defined by using the Kriging interpolation algorithm relying on a support vector machine(SVM)and the formation pressure of the drilled wells.To validate the method,the formation pressure of one pre-drilled well is compared with the well logging results.The comparison reveals that the maximum relative error is less than 4.5%.The software based on this model is complemented by a computer visualization technology,which provides a relevant tool for under-standing and analyzing the 3D formation pressure.The outcomes of this study are intended to support the char-acterization of areas with missing or poor 3D seismic data and provide more accurate information for the analysis of wellbore integrity.展开更多
In this study, we investigated the effect of compression on the micromechanical and the petro- physical properties of salted wellbore cement systems. The experiments were conducted using a customized bench scale model...In this study, we investigated the effect of compression on the micromechanical and the petro- physical properties of salted wellbore cement systems. The experiments were conducted using a customized bench scale model, which utilized an expandable tubulars simulating the compression of a previously cemented casing under field-like conditions. The “mini-wellbore model” sample consisted of a pipe inside pipe assembly with a cemented annulus. The cement samples were cured in a water bath for 28 days prior to the compression experiments to allow adequate hydration. The impact of compression on the cement’s petro-physical and mechanical properties was quantified by measuring the porosity, permeability and hardness of salt cement cores drilled parallel to the orientation of the pipe from the compacted cement sheath. Permeability (Core-flood) experiments were conducted at 21℃, 10,342 kPa confining pressure for a period of 120 minutes. During the core-flood experiments, conducted using Pulse-decay method, deionized water was flowed through cement cores to determine the permeability of the cores. The results obtained from these experiments confirmed that the compression of the cement positively impacted the cements ability to provide long term zonal isolation, shown by the effective reduction in porosity and permeability. Furthermore, the results confirm reduction in the detrimental effect of salt on the strength and stiffness in post-compression cement.展开更多
Plugging and abandonment(P&A)is a crucial step of the well life cycle.Regardless of how long one stretches the productive life of a well,P&A operations will have to be carried out eventually.The current panora...Plugging and abandonment(P&A)is a crucial step of the well life cycle.Regardless of how long one stretches the productive life of a well,P&A operations will have to be carried out eventually.The current panorama of our industry includes many wells to be plugged and abandoned,with steep requirements to abide by both regulations and societal pressure.In this context,we must guarantee that no leakage occurs with an eternal perspective in mind.Cement has been the prime material for this task,but recent studies have indicated the potential of degradation over time-especially in corrosive environments-and the creation of leaking paths due to its shrinkage.This has opened up a path toward the usage of alternative materials.One of the emerging candidates is bismuth,a metal with the unique characteristic of expanding when solidified.Such a trait could improve the overall sealability of wellbores and especially during P&A.This article discusses the current status of bismuth sealing technologies,introducing the basics of bismuth,the ongoing efforts to qualify it as a barrier material,its potential applications,and the challenges that still need to be overcome.The latest research indicates promising results in terms of its usage as a barrier element.展开更多
文摘Well integrity technology can effectively ensure the safety of the entire life cycle of oil and gas wells. With the exploration and development of more and more high-temperature, high-pressure, high-yield and deep wells, and the constantly increasing requirements for safety and environmental protection in various countries, well integrity technology has become a research hot spot in the oil industry. Based on the analysis of the four basic concepts of well integrity: full life cycle, well integrity management system, well barrier, and risk assessment, this article conducts a comparative analysis of the development history of well integrity technologies at home and abroad, and systematically summarizes foreign wells. The current status of integrity technology, based on the above investigation and analysis, puts forward suggestions for the next development direction of well integrity technology, which has certain guiding significance for the development of the integrity of the next step.
基金supported by Scientific Research and Technology Development Project of CNPC“Study on Exploration and Development Theory and Key Technology of Gulong Shale Oil in Daqing”(2021ZZ10-03)Scientific Research and Technology Development Project of CNPC“Development of Integrated Software(Smart Drilling)for Drilling and Completion Engineering Design and Optimization Decision”(2020B-4019)+1 种基金Scientific Research and Technology Development Project of CNPC“Integration and Experiment of Safe,Optimal and Fast Drilling and Completion Technology for Complex Ultra Deep Wells”(2020F-46)project funded by China Postdoctoral Science Foundation“Research on the Effect of Stress Distribution Difference on Acoustic Propagation Characteristics in Drill String”(2021M693508).
文摘Formation pressure is the key parameter for the analysis of wellbore safety.With increasing drilling depth,how-ever,the behavior of this variable becomes increasingly complex.In this work,a 3D model of the formation pres-sure under uncertainty is presented.Moreover a relevant algorithm is elaborated.First,the logging data of regional key drilling wells are collected and a one-dimensional formation pressure profile along the well depth is determined.Then,a 3D model of regional formation pressure of the hierarchical group layer is defined by using the Kriging interpolation algorithm relying on a support vector machine(SVM)and the formation pressure of the drilled wells.To validate the method,the formation pressure of one pre-drilled well is compared with the well logging results.The comparison reveals that the maximum relative error is less than 4.5%.The software based on this model is complemented by a computer visualization technology,which provides a relevant tool for under-standing and analyzing the 3D formation pressure.The outcomes of this study are intended to support the char-acterization of areas with missing or poor 3D seismic data and provide more accurate information for the analysis of wellbore integrity.
文摘In this study, we investigated the effect of compression on the micromechanical and the petro- physical properties of salted wellbore cement systems. The experiments were conducted using a customized bench scale model, which utilized an expandable tubulars simulating the compression of a previously cemented casing under field-like conditions. The “mini-wellbore model” sample consisted of a pipe inside pipe assembly with a cemented annulus. The cement samples were cured in a water bath for 28 days prior to the compression experiments to allow adequate hydration. The impact of compression on the cement’s petro-physical and mechanical properties was quantified by measuring the porosity, permeability and hardness of salt cement cores drilled parallel to the orientation of the pipe from the compacted cement sheath. Permeability (Core-flood) experiments were conducted at 21℃, 10,342 kPa confining pressure for a period of 120 minutes. During the core-flood experiments, conducted using Pulse-decay method, deionized water was flowed through cement cores to determine the permeability of the cores. The results obtained from these experiments confirmed that the compression of the cement positively impacted the cements ability to provide long term zonal isolation, shown by the effective reduction in porosity and permeability. Furthermore, the results confirm reduction in the detrimental effect of salt on the strength and stiffness in post-compression cement.
基金funded by the Research Council of Norway.The authors acknowledge the Research Council of Norway(RCN)for financing the Center for Research-based Innovations“SWIPA-Center for Subsurface Well Integrity,Plugging and Abandonment”,RCN project no.309646,for which the work has been carried out.The center is also financed by the operating companies AkerBP,Equinor ASA,and Wintershall Dea Norway,and includes in addition more than 20 in-kind contributing industry partners.The R&D partners in SWIPA are SINTEF,NORCE,IFE,NTNU,and UiS.
文摘Plugging and abandonment(P&A)is a crucial step of the well life cycle.Regardless of how long one stretches the productive life of a well,P&A operations will have to be carried out eventually.The current panorama of our industry includes many wells to be plugged and abandoned,with steep requirements to abide by both regulations and societal pressure.In this context,we must guarantee that no leakage occurs with an eternal perspective in mind.Cement has been the prime material for this task,but recent studies have indicated the potential of degradation over time-especially in corrosive environments-and the creation of leaking paths due to its shrinkage.This has opened up a path toward the usage of alternative materials.One of the emerging candidates is bismuth,a metal with the unique characteristic of expanding when solidified.Such a trait could improve the overall sealability of wellbores and especially during P&A.This article discusses the current status of bismuth sealing technologies,introducing the basics of bismuth,the ongoing efforts to qualify it as a barrier material,its potential applications,and the challenges that still need to be overcome.The latest research indicates promising results in terms of its usage as a barrier element.
