Water sealing performance is important for underground water-sealed oil storage(UWSOS).The key issues concerning water sealing performance mainly include the permeability of fractured rock mass(FRM),water-sealed safet...Water sealing performance is important for underground water-sealed oil storage(UWSOS).The key issues concerning water sealing performance mainly include the permeability of fractured rock mass(FRM),water-sealed safety(WSS),water curtain performance,and prediction and control of water inflow.This paper reviews the progress of above four key issues on water sealing performances.First,the permeability of an FRM is the basis of water sealing performance,and several commonly used permeability test methods and spatial variation characteristics of permeability are outlined.Second,the current water sealing criteria are compared,and the evaluation methods of WSS are summarized.Third,the design parameters and efficiency evaluation of water curtain systems(WCSs)are introduced.The water inflow of oil storage caverns(OSCs)can reflect the water sealing effect,and the prediction methods and control measures of water inflow are also summarized.Finally,the advantages and disadvantages of the current research are discussed,and the potential research directions are pointed out,such as optimization of water sealing criteria and FRM model,quantitative evaluation of WCS efficiency,accurate prediction of water inflow,and improvement of grouting technology.展开更多
Static and dynamic continuous cooling transformations （CCT） of 610 MPa HSLA steel plate for 150000 m^3 oil storage tank construction were measured by using an MMS200 thermomechanical simulation system. It was found ...Static and dynamic continuous cooling transformations （CCT） of 610 MPa HSLA steel plate for 150000 m^3 oil storage tank construction were measured by using an MMS200 thermomechanical simulation system. It was found that with the increase in cooling rate, the proeutectoid ferrite, pearlite, granular bainite, and lath bainite appeared in the transformed microstructure. Compared with those of static CCT, the transformation points of acicular ferrite, granular bainite, and lath bainite in the dynamic CCT curve were shifted to the left, resulting in an increased acicular ferrite and bainite transformation area.展开更多
Water curtain systems(WCSs)are key components for the operation of underground oil storage caverns(UOSCs)and their optimization and design are important areas of research.Based on the time series monitoring of the fir...Water curtain systems(WCSs)are key components for the operation of underground oil storage caverns(UOSCs)and their optimization and design are important areas of research.Based on the time series monitoring of the first large-scale underground water-sealed storage cavern project in China,and on finite element analysis,this study explores the optimum design criteria for WCSs in water-sealed oil caverns.It shows that the optimal hole spacing of the WCS for this underground storage cavern is 10 m in order to ensure seal effectiveness.When the WCS is designed with a 10-m horizontal hole spacing and a water curtain pressure(WCP)of 80 kPa,a water curtain hole(WCH)has an influence radius of approximately 25 m.The smaller the vertical distance is between a WCH and the main cavern,the greater the water inflow into the main cavern.The vertical hydraulic gradient criterion can be satisfied when this distance is 25 m.It shows that the optimal WCP is 70 kPa,which meets sealing requirements.展开更多
The underground water-sealed storage technique is critically important and generally accepted for the national energy strategy in China. Although several small underground water-sealed oil storage caverns have been bu...The underground water-sealed storage technique is critically important and generally accepted for the national energy strategy in China. Although several small underground water-sealed oil storage caverns have been built in China since the 1970s, there is still a lack of experience for large-volume underground storage in complicated geological conditions. The current design concept of water curtain system and the technical instruction for system operation have limitations in maintaining the stability of surrounding rock mass during the construction of the main storage caverns, as well as the long-term stability. Although several large-scale underground oil storage projects are under construction at present in China, the design concepts and construction methods, especially for the water curtain system, are mainly based on the ideal porosity medium flow theory and the experiences gained from the similar projects overseas. The storage projects currently constructed in China have the specific features such as huge scale, large depth, multiple-level arrangement, high seepage pressure, complicated geological conditions, and high in situ stresses, which are the challenging issues for the stability of the storage caverns. Based on years’ experiences obtained from the first large-scale （millions of cubic meters） underground water-sealed oil storage project in China, some design and operation problems related to water curtain system during project construction are discussed. The drawbacks and merits of the water curtain system are also presented. As an example, the conventional concept of “filling joints with water” is widely used in many cases, as a basic concept for the design of the water curtain system, but it is immature. In this paper, the advantages and disadvantages of the conventional concept are pointed out, with respect to the long-term stability as well as the safety of construction of storage caverns. Finally, new concepts and principles for design and construction of the underground water-sealed oil storage caverns are proposed.展开更多
A Constrained Interpolation Profile （CIP）-based model is developed to predict the mooring force of a two-dimensional floating oil storage tank under wave conditions, which is validated against to a newly performed e...A Constrained Interpolation Profile （CIP）-based model is developed to predict the mooring force of a two-dimensional floating oil storage tank under wave conditions, which is validated against to a newly performed experiment. In the experiment, a box-shaped floating oil storage apparatus is used. Computations are performed by an improved CIP-based Cartesian grid model, in which the THINC/SW scheme （THINC： tangent of hyperbola for interface capturing; SW： Slope Weighting）, is used for interface capturing. A multiphase flow solver is adopted to treat the water-air-body interactions. The Immersed Boundary Method （IBM） is implemented to treat the body surface. Main attention is paid to the sum force of mooring line and velocity field around the body. It is found that the sum force of the mooring line increases with increasing wave amplitude. The body suffers from water wave impact and large body motions occur near the free surface. The vortex occurs near the sharp edge, i.e., the sharp bottom comers of the float- ing oil storage tank and the vortex shedding can be captured by the present numerical model. The present model could be further improved by including turbulence model which is currently under development. Comparison between the computational mooring forces and the measured mooring forces is presented with a reasonable agreement. The developed numerical model can predict the mooring line forces very well.展开更多
The hydroelastic behavior of a moored oil storage vessel subjected to arbitrary time-dependent external loads,which include wind,waves,and currents with different incident directions,is investigated with the time-doma...The hydroelastic behavior of a moored oil storage vessel subjected to arbitrary time-dependent external loads,which include wind,waves,and currents with different incident directions,is investigated with the time-domain modal expansion method.First,the water boundary integral equations on the body surface of a quarter model,which can be obtained via the free-surface Green’s function method,are established.Then,the time-dependent elastic deflection of the moored oil storage vessel is expressed by a superposition of modal functions and corresponding modal amplitudes,and a Galerkin scheme is applied to derive the linear system of equations for the modal amplitudes.The second-order linear differential equations for modal amplitudes are solved via the fourth-order Runge−Kutta method.The present model is validated against existing frequency domain results for a truncated cylinder and a VLFS.Numerical calculations for the moored oil storage vessel are then conducted to obtain the time series of various modal amplitudes and elastic displacements of the measurement points and the corresponding spectra with different incident directions.展开更多
The floating oil storage system has been proposed as a new facility for Strategic Petroleum Reserve (SPR) in China. Mooring is one of the key technologies to ensure the safety, reliability, and performance of the oil ...The floating oil storage system has been proposed as a new facility for Strategic Petroleum Reserve (SPR) in China. Mooring is one of the key technologies to ensure the safety, reliability, and performance of the oil storage system. This paper describes the concept, analysis, design and reliability of the mooring system. For mooring system design of these oil vessels, analysis is essential of the behavior of the vessel in connection with mooring facilities of nonlinear resilience. A nonlinear mathematical model for analyzing a moored vessel is established and solved. Some results of numerical simulations are presented. Assessment of the safety regarding the mooring system in terms of failure probability is carried out. Another simulation model for calculating the failure probability of the mooring system is proposed. The design parameters that have an influence on the characteristics of the failure probability have been identified. The simulation results,show that the mooring system has an annual reliability value of 0.999998. The proposed simulation method is proved to be effective in quantitative evaluation of the safety of the mooring system for floating oil storage vessels.展开更多
To ensure the airtightness of salt cavern oil storage in layered salt rock,this study investigates the porosity and permeability characteristics and seepage laws of the surrounding rock of the storage caverns under th...To ensure the airtightness of salt cavern oil storage in layered salt rock,this study investigates the porosity and permeability characteristics and seepage laws of the surrounding rock of the storage caverns under the erosion of crude oil and brine.Salt rock,interlayer,and cap rock samples from the Jintan salt cavern storage in Jiangsu,China,were used.The porosity and permeability changes of the samples were measured under different static water pressures,different erosion times,and different working conditions(crude oil erosion and brine erosion).Finally,based on the theory of single-phase liquid stable seepage,liquid seepage models for interlayer and cap rock were established.The results show that the porosity and permeability parameters of the surrounding rock are not affected by stress changes under different working conditions.The wetting of crude oil covers the pore structure inside the surrounding rock,enhancing its airtightness macroscopically and thus favoring the long-term airtightness of the salt cavern oil storage.In contrast,brine erosion destroys the pore structure inside the surrounding rock,severely deteriorating its airtightness macroscopically,which seriously affects the lifespan of the storage cavern and is detrimental to the long-term airtightness of the salt cavern oil storage.Based on the assumption of single-phase liquid stable seepage,the leakage of the storage cavern was calculated.The calcu-lations of gas and liquid leakage were corrected according to the airtightness standards of gas storage caverns and combined with existing simulation parameters,which to some extent proved the accuracy of the liquid seepage models for interlayer and cap rock.展开更多
The problem of petroleum safety is closely related to national politics andeconomics security and becomes one of key for discussion in China. The floating oil storage systemhas been proposed as a new facility for Stra...The problem of petroleum safety is closely related to national politics andeconomics security and becomes one of key for discussion in China. The floating oil storage systemhas been proposed as a new facility for Strategic Petroleum Reserve (SPR) in our country. There aresome differences in solving this problem. Although many of domestic research institutions arestudying the project of SPR, the research is separate, and lack of comprehensive consideration, andfails to make a complete and scientific demonstration in many aspects, such as oil storage capacity,selection of storage sites, storage facilities, technologic and economic feasibility, riskassessment, etc. Therefore, no mature and systematic petroleum reserve theories have been formed upto now. Peoples argue the issue of objective of SPR, function, mode, cost, effect, etc. There arestill many bifurcations, so, it is necessary to make more detailed demonstration, and provide somescientific decision-making strategy for the governments. In this paper, several significant problemsare solved, for instance, the option of SPR facilities, the research on the principalcharacteristics of floating oil storage vessels, the a-nalysis of mooring system for oil storagevessels, the design of breakwater and the calculation of failure probability, the risk assessment offloating oil storage system, etc.展开更多
The internal turret mooring system for oil production storage vessels is a developing type ofoffshore floating production system suitable for deep water and harsh environmental application. In this paper, some achieve...The internal turret mooring system for oil production storage vessels is a developing type ofoffshore floating production system suitable for deep water and harsh environmental application. In this paper, some achievements in our research work are presented. The description includes: dynamic analysis of mooring system, research on performance of turret assembly, influence of vessel dimensions and hull forms on mooring performance, model tests under combined action of environmental forces in basin, and hull structural strength analysis.展开更多
In the process of the constant development of the oil and gas storage and transportation technology, the maintenance of the large pipelines is an important task. At present, China vigorously promotes the use of the pi...In the process of the constant development of the oil and gas storage and transportation technology, the maintenance of the large pipelines is an important task. At present, China vigorously promotes the use of the pipeline robots, for the maintenance of the oil and gas pipelines by the unique characteristics of the robots. In this paper, the author carries out the detailed analysis on the current situation of the development of the pipeline robots in the oil and gas storage and transportation industry, and compares the different applications of the pipeline robots at home and abroad. Starting from the principles of the operation of the robots, the author analyzes the characteristics of the different types of the robots, and combined with the existing conditions of the oil and gas storage and transportation in our country, the author tries to find the most favorable way of the working of the pipeline robots, to continuously improve the development of the oil and gas storage and transportation industry using the robot technologies.展开更多
In recent years, our country is increasingly dependent on the use of the oil resources, and the degree of the oil mining is also continuously upgrading. After the completion of the tasks related to the oil mining in t...In recent years, our country is increasingly dependent on the use of the oil resources, and the degree of the oil mining is also continuously upgrading. After the completion of the tasks related to the oil mining in the lands, the technologies for the development of the offshore oil mining are particularly important. Among these problems, after the exploitation, the storage and transportation of the offshore oil and gas is worthy of the discussion of the technical personnel. From the experience of the oil and gas storage and transportation in the long years, in some environmentally degraded areas, there are problems in the efficiency and safety in the long pipeline transportation and the oil and gas mixed transportation, and in the transportation, there are also big shortcomings. In this paper, the author carries on the analysis of the existing questions encountering in our country＇s oil and gas storage and transportation~ and proposes the direction of the researches in the future oil and gas storage and transportation, and the purpose is to better improve the security of Cbina＇s oil and gas storage and transportation and to enhance the efficiency of the use of the oil and gas.展开更多
Oil is an important resource for a country's development, which involves many aspects of social development. It is also an important pillar of economic development and promotes the all-round development of society...Oil is an important resource for a country's development, which involves many aspects of social development. It is also an important pillar of economic development and promotes the all-round development of society. In the current era, people's demand for oil resources is gradually increasing, which leads to the prominent importance of oil and gas storage and transportation equipment management. The industry needs to optimize according to the actual situation at this stage, clarify the new situation of development, integrate existing resources and create a new development system, so as to improve the overall security and adapt to the development of the times.展开更多
In recent years,the safety of oil and gas storage and transportation facilities has been paid more attention by the state and enterprises due to frequent accidents.The oil and gas storage and transportation facilities...In recent years,the safety of oil and gas storage and transportation facilities has been paid more attention by the state and enterprises due to frequent accidents.The oil and gas storage and transportation facilities safety courses in China University of Petroleum(Beijing)includes“Engineering mechanics”,“Strength design of pipelines and tanks”and“Safety and integrity management of oil and gas storage and transportation facilities”.The three courses lack relevance and the teaching mode is too rigid,resulting in students losing their initiative in learning.If students can’t use the knowledge flexibly,it will affect the achievement of the objectives of the training program.Therefore,oil and gas storage and transportation facilities safety courses are reformed,training plans are adjusted and teaching methods are improved.The practice shows that the reform enriches the teaching content,improves the teaching quality,stimulates classroom activity and gets a good evaluation of students.The reform of safety courses has a certain significance for cultivating compound talents who have the ability to solve practical problems in engineering.展开更多
Oil and gas can be stored underground by a variety of means,such as in depleted oil and gas fields,in aquifers,in rock salt caverns,in unlined mined rock caverns,in lined shallow caverns and abandoned mines.Different ...Oil and gas can be stored underground by a variety of means,such as in depleted oil and gas fields,in aquifers,in rock salt caverns,in unlined mined rock caverns,in lined shallow caverns and abandoned mines.Different types of underground storages require different geological and hydrogeological conditions and are associated with different rock engineering problems.However,the common issue is to ensure the gas-and oil-tightness of storage caverns.In other words,the stored oil and gas must not escape from the storage caverns.This may be realized by different means according to the types of storages and the sites geological conditions.There are basically two approaches of gas leakage control,i.e.permeability control and hydrodynamic containment.The latter involves the use of a water curtain system in many cases,which creates an artificial hydraulic boundary condition and helps to establish the required groundwater condition when needed.In addition to the common problems,the underground storage of liquefied petroleum gas(LPG) requires special attentions to the opening of rock joints,which result from the tensile thermal stress induced by the low storage temperature.Great care must be taken in choosing abandoned mines for oil and gas-storage since it is quite rare that the natural site conditions can meet the usual requirements,in particular for the gas tightness.The paper provides a general description of the gas leakage control for underground oil and gas storage projects,and addresses various rock engineering problems associated with selected types of storages in detail.展开更多
Oil and gas resources are short in Pakistan and no commercially viable oil and gas sources have been yet discovered in its offshore areas up to now.In this study,the onshore-offshore stratigraphic correlation and seis...Oil and gas resources are short in Pakistan and no commercially viable oil and gas sources have been yet discovered in its offshore areas up to now.In this study,the onshore-offshore stratigraphic correlation and seismic data interpretation were conducted to determine the oil and gas resource potential in the Offshore Indus Basin,Pakistan.Based on the comprehensive analysis of the results and previous data,it is considered that the Cretaceous may widely exist and three sets of source rocks may be developed in the Offshore Indus Basin.The presence of Miocene mudstones has been proven by drilling to be high-quality source rocks,while the Cretaceous and Paleocene–Eocene mudstones are potential source rocks.Tectonic-lithologic traps are developed in the northwestern part of the basin affected by the strike-slip faults along Murray Ridge.Furthermore,the Cretaceous and Paleocene–Eocene source rocks are thick and are slightly affected by volcanic activities.Therefore,it can be inferred that the northwestern part of Offshore Indus Basin enjoys good prospects of oil and gas resources.展开更多
Accidents in engineered systems are usually generated by complex socio-technical factors.It is beneficial to investigate the increasing complexity and coupling of these factors from the perspective of system safety.Ba...Accidents in engineered systems are usually generated by complex socio-technical factors.It is beneficial to investigate the increasing complexity and coupling of these factors from the perspective of system safety.Based on system and control theories,System-Theoretic Accident Model and Processes(STAMP)is a widely recognized approach for accident analysis.In this paper,we propose a STAMP-Game model to analyze accidents in oil and gas storage and transportation systems.Stakeholders in accident analysis by STAMP can be regarded as players of a game.Game theory can,thus,be adopted in accident analysis to depict the competition and cooperation between stakeholders.Subsequently,we established a game model to study the strategies of both supervisory and supervised entities.The obtained results demonstrate that the proposed game model allows for identifying the effectiveness deficiency of the supervisory entity,and the safety and protection altitudes of the supervised entity.The STAMP-Game model can generate quantitative parameters for supporting the behavior and strategy selections of the supervisory and supervised entities.The quantitative data obtained can be used to guide the safety improvement,to reduce the costs of safety regulation violation and accident risk.展开更多
The amount of shale oil and its characterization are key issues in the study of shale oil.At present,many scholars use a variety of methods to evaluate the amount of shale oil,and use the calculated amount of hydrocar...The amount of shale oil and its characterization are key issues in the study of shale oil.At present,many scholars use a variety of methods to evaluate the amount of shale oil,and use the calculated amount of hydrocarbons to analyze its influencing factors;however,there is lack of detailed research on the storage space for shale-oil and it’s influencing factors.In view of this issue,gas chromatography(GC),gas chromatography-mass spectrometry(GC-MS),soxhlet extraction(SE),fieldemission scanning electron microscopy(FE-SEM),low-temperature nitrogen adsorption(LTNA),highpressure mercury intrusion(HPMI),and X-ray diffraction(XRD)were used to analyze and compare samples from two wells located in different deposition locations.The unconventional Well BYY2 and BX7 s were drilled in the depocenter and distal area of the Qianjiang Formation,respectively.Controlled by differences in the organic matter type and sedimentary environment,the organic matter in Well BYY2,which was found to be characterized by laminar shale,mainly originated from aquatic algae.The results showed that as the total organic carbon(TOC)content increased,the amount of shaleoil in the pores increased.Shale-oil was mostly stored in mesopores and macropores that had been preserved by dolomite minerals of a biogenic origin and also occurred in pores sized 5–200 nm and>1μm.Dolomite minerals of a biogenic origin and clay minerals contributed to the occurrence of shaleoil.In comparison,the organic matter in Well BX7 has been greatly influenced by terrestrial organic matter.Pores in the massive mudstones from Well BX7 were determined to be mainly mesopores preserved by clay minerals and quartz,and the shale-oil was mostly stored within the pores of<40 nm.When the TOC content was~2.5 wt.%,the generated shale-oil reached saturation.Clay minerals contributed to the occurrence of shale-oil,whereas quartz only contributed to the occurrence of shale-oil in macropores.展开更多
Whole-life-cycle integrity management of underground gas storages(UGSs)has been an important link to ensure its long-term safe and efficient operation.At present,the integrity of UGSs in oil/gasfields and its evaluati...Whole-life-cycle integrity management of underground gas storages(UGSs)has been an important link to ensure its long-term safe and efficient operation.At present,the integrity of UGSs in oil/gasfields and its evaluation techniques focus on surface facilities and injection/withdrawal wells,but its geological integrity lacks clear definition and evaluation object and systematic evaluation techniques.In this paper,relevant research achievements werefirstly summarized.Then,the concept of geological integrity with the gas-storage geological body as the evaluation object was put forward,and the evaluation system for the geological integrity of such UGSs was established.Finally,UGS geological integrity evaluation was carried out with the Hutubi Underground Gas Storage in Xinjiang as an example.And the following research results were obtained.First,UGS geological integrity is defined as the integrity degree of each component of a gas-storage geological body to meet operation requirements and fulfill seasonal and emergency peak shaving safely and economically during the operation of a UGS.Its connotation is that reservoir of geological body,caprock,fault and trap can supply the customers with gas continuously and stably and ensure the safe operation of the UGS in its service life.And its core lies in keeping the reliability,safety and economy of natural gas storage in the service life of a UGS.Second,the geological integrity evaluation system is composed of four evaluation techniques,including trap effectiveness,caprock integrity,fault stability and reservoir stability.Third,the evaluation results show that the Hutubi Underground Gas Storage has the potential of peak-shaving capacity enhancement by increasing the maximum operation pressure.In conclusion,the establishment of the geological integrity evaluation system for such UGSs improves the UGS integrity evaluation technique system and plays an instructive and practical role in ensuring the long-term safe and efficient operation of UGSs,increasing the maximum operation pressure and improving the peak shaving capacity.展开更多
This project investigated the potential optimal development strategy for a saturated reservoir, with a gas cap. It assessed the viability of three production methods—solution gas drive (primary depletion), water floo...This project investigated the potential optimal development strategy for a saturated reservoir, with a gas cap. It assessed the viability of three production methods—solution gas drive (primary depletion), water flooding and gas injection, using varying injector well numbers. This project also undertook sensitivity analysis in the field, concluding that the development of another appraisal well would vastly improve the accuracy of NPV calculation. Furthermore, this project ascertained an optimized recovery method, based on numerical production simulations and economic modelling, of initial solution gas drive recovery, until reservoir pressure equals the bubble point pressure, at which point three water flooding injectors should be employed, developed at six-month intervals to maximise production while limiting CAPEX and OPEX as much as possible.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.41972300,41572301,and 42107201).
文摘Water sealing performance is important for underground water-sealed oil storage(UWSOS).The key issues concerning water sealing performance mainly include the permeability of fractured rock mass(FRM),water-sealed safety(WSS),water curtain performance,and prediction and control of water inflow.This paper reviews the progress of above four key issues on water sealing performances.First,the permeability of an FRM is the basis of water sealing performance,and several commonly used permeability test methods and spatial variation characteristics of permeability are outlined.Second,the current water sealing criteria are compared,and the evaluation methods of WSS are summarized.Third,the design parameters and efficiency evaluation of water curtain systems(WCSs)are introduced.The water inflow of oil storage caverns(OSCs)can reflect the water sealing effect,and the prediction methods and control measures of water inflow are also summarized.Finally,the advantages and disadvantages of the current research are discussed,and the potential research directions are pointed out,such as optimization of water sealing criteria and FRM model,quantitative evaluation of WCS efficiency,accurate prediction of water inflow,and improvement of grouting technology.
基金Item Sponsored by National Key Technology Research and Development Program of China (2007BAE51B07)
文摘Static and dynamic continuous cooling transformations （CCT） of 610 MPa HSLA steel plate for 150000 m^3 oil storage tank construction were measured by using an MMS200 thermomechanical simulation system. It was found that with the increase in cooling rate, the proeutectoid ferrite, pearlite, granular bainite, and lath bainite appeared in the transformed microstructure. Compared with those of static CCT, the transformation points of acicular ferrite, granular bainite, and lath bainite in the dynamic CCT curve were shifted to the left, resulting in an increased acicular ferrite and bainite transformation area.
基金Project supported by the National Natural Science Foundation of China (Nos. 41877239, 51379112, 51422904, 40902084, and 41772298)the Fundamental Research Funds for the Central Universities (No. 2018JC044)the Natural Science Foundation of Shandong Province (No. JQ201513),China。
文摘Water curtain systems(WCSs)are key components for the operation of underground oil storage caverns(UOSCs)and their optimization and design are important areas of research.Based on the time series monitoring of the first large-scale underground water-sealed storage cavern project in China,and on finite element analysis,this study explores the optimum design criteria for WCSs in water-sealed oil caverns.It shows that the optimal hole spacing of the WCS for this underground storage cavern is 10 m in order to ensure seal effectiveness.When the WCS is designed with a 10-m horizontal hole spacing and a water curtain pressure(WCP)of 80 kPa,a water curtain hole(WCH)has an influence radius of approximately 25 m.The smaller the vertical distance is between a WCH and the main cavern,the greater the water inflow into the main cavern.The vertical hydraulic gradient criterion can be satisfied when this distance is 25 m.It shows that the optimal WCP is 70 kPa,which meets sealing requirements.
文摘The underground water-sealed storage technique is critically important and generally accepted for the national energy strategy in China. Although several small underground water-sealed oil storage caverns have been built in China since the 1970s, there is still a lack of experience for large-volume underground storage in complicated geological conditions. The current design concept of water curtain system and the technical instruction for system operation have limitations in maintaining the stability of surrounding rock mass during the construction of the main storage caverns, as well as the long-term stability. Although several large-scale underground oil storage projects are under construction at present in China, the design concepts and construction methods, especially for the water curtain system, are mainly based on the ideal porosity medium flow theory and the experiences gained from the similar projects overseas. The storage projects currently constructed in China have the specific features such as huge scale, large depth, multiple-level arrangement, high seepage pressure, complicated geological conditions, and high in situ stresses, which are the challenging issues for the stability of the storage caverns. Based on years’ experiences obtained from the first large-scale （millions of cubic meters） underground water-sealed oil storage project in China, some design and operation problems related to water curtain system during project construction are discussed. The drawbacks and merits of the water curtain system are also presented. As an example, the conventional concept of “filling joints with water” is widely used in many cases, as a basic concept for the design of the water curtain system, but it is immature. In this paper, the advantages and disadvantages of the conventional concept are pointed out, with respect to the long-term stability as well as the safety of construction of storage caverns. Finally, new concepts and principles for design and construction of the underground water-sealed oil storage caverns are proposed.
基金supported by the National Natural Science Foundation of China (51209184,51279186,51479175)
文摘A Constrained Interpolation Profile （CIP）-based model is developed to predict the mooring force of a two-dimensional floating oil storage tank under wave conditions, which is validated against to a newly performed experiment. In the experiment, a box-shaped floating oil storage apparatus is used. Computations are performed by an improved CIP-based Cartesian grid model, in which the THINC/SW scheme （THINC： tangent of hyperbola for interface capturing; SW： Slope Weighting）, is used for interface capturing. A multiphase flow solver is adopted to treat the water-air-body interactions. The Immersed Boundary Method （IBM） is implemented to treat the body surface. Main attention is paid to the sum force of mooring line and velocity field around the body. It is found that the sum force of the mooring line increases with increasing wave amplitude. The body suffers from water wave impact and large body motions occur near the free surface. The vortex occurs near the sharp edge, i.e., the sharp bottom comers of the float- ing oil storage tank and the vortex shedding can be captured by the present numerical model. The present model could be further improved by including turbulence model which is currently under development. Comparison between the computational mooring forces and the measured mooring forces is presented with a reasonable agreement. The developed numerical model can predict the mooring line forces very well.
基金financially supported by the Department of Natural Resources of Guangdong Province(Grant No.[2024]31)the National Natural Science Foundation of China(Grant No.52071145)+1 种基金the Natural Science Foundation of Guangdong Province,China(Grant No.2022B1515020071)the Fundamental Research Funds for the Central Universities(Grant No.2023ZYGXZR029).
文摘The hydroelastic behavior of a moored oil storage vessel subjected to arbitrary time-dependent external loads,which include wind,waves,and currents with different incident directions,is investigated with the time-domain modal expansion method.First,the water boundary integral equations on the body surface of a quarter model,which can be obtained via the free-surface Green’s function method,are established.Then,the time-dependent elastic deflection of the moored oil storage vessel is expressed by a superposition of modal functions and corresponding modal amplitudes,and a Galerkin scheme is applied to derive the linear system of equations for the modal amplitudes.The second-order linear differential equations for modal amplitudes are solved via the fourth-order Runge−Kutta method.The present model is validated against existing frequency domain results for a truncated cylinder and a VLFS.Numerical calculations for the moored oil storage vessel are then conducted to obtain the time series of various modal amplitudes and elastic displacements of the measurement points and the corresponding spectra with different incident directions.
文摘The floating oil storage system has been proposed as a new facility for Strategic Petroleum Reserve (SPR) in China. Mooring is one of the key technologies to ensure the safety, reliability, and performance of the oil storage system. This paper describes the concept, analysis, design and reliability of the mooring system. For mooring system design of these oil vessels, analysis is essential of the behavior of the vessel in connection with mooring facilities of nonlinear resilience. A nonlinear mathematical model for analyzing a moored vessel is established and solved. Some results of numerical simulations are presented. Assessment of the safety regarding the mooring system in terms of failure probability is carried out. Another simulation model for calculating the failure probability of the mooring system is proposed. The design parameters that have an influence on the characteristics of the failure probability have been identified. The simulation results,show that the mooring system has an annual reliability value of 0.999998. The proposed simulation method is proved to be effective in quantitative evaluation of the safety of the mooring system for floating oil storage vessels.
基金financial supports of the National Natural Science Foundation of China Youth Science Foundation Project(52204152,52204111,52204153)the Postdoctoral Innovation Talent Support Program(BX2020275)the Postdoctoral Science Foun-dation(2020M683521).
文摘To ensure the airtightness of salt cavern oil storage in layered salt rock,this study investigates the porosity and permeability characteristics and seepage laws of the surrounding rock of the storage caverns under the erosion of crude oil and brine.Salt rock,interlayer,and cap rock samples from the Jintan salt cavern storage in Jiangsu,China,were used.The porosity and permeability changes of the samples were measured under different static water pressures,different erosion times,and different working conditions(crude oil erosion and brine erosion).Finally,based on the theory of single-phase liquid stable seepage,liquid seepage models for interlayer and cap rock were established.The results show that the porosity and permeability parameters of the surrounding rock are not affected by stress changes under different working conditions.The wetting of crude oil covers the pore structure inside the surrounding rock,enhancing its airtightness macroscopically and thus favoring the long-term airtightness of the salt cavern oil storage.In contrast,brine erosion destroys the pore structure inside the surrounding rock,severely deteriorating its airtightness macroscopically,which seriously affects the lifespan of the storage cavern and is detrimental to the long-term airtightness of the salt cavern oil storage.Based on the assumption of single-phase liquid stable seepage,the leakage of the storage cavern was calculated.The calcu-lations of gas and liquid leakage were corrected according to the airtightness standards of gas storage caverns and combined with existing simulation parameters,which to some extent proved the accuracy of the liquid seepage models for interlayer and cap rock.
文摘The problem of petroleum safety is closely related to national politics andeconomics security and becomes one of key for discussion in China. The floating oil storage systemhas been proposed as a new facility for Strategic Petroleum Reserve (SPR) in our country. There aresome differences in solving this problem. Although many of domestic research institutions arestudying the project of SPR, the research is separate, and lack of comprehensive consideration, andfails to make a complete and scientific demonstration in many aspects, such as oil storage capacity,selection of storage sites, storage facilities, technologic and economic feasibility, riskassessment, etc. Therefore, no mature and systematic petroleum reserve theories have been formed upto now. Peoples argue the issue of objective of SPR, function, mode, cost, effect, etc. There arestill many bifurcations, so, it is necessary to make more detailed demonstration, and provide somescientific decision-making strategy for the governments. In this paper, several significant problemsare solved, for instance, the option of SPR facilities, the research on the principalcharacteristics of floating oil storage vessels, the a-nalysis of mooring system for oil storagevessels, the design of breakwater and the calculation of failure probability, the risk assessment offloating oil storage system, etc.
基金Project supported by special scientific research foundation for doctoral subjects
文摘The internal turret mooring system for oil production storage vessels is a developing type ofoffshore floating production system suitable for deep water and harsh environmental application. In this paper, some achievements in our research work are presented. The description includes: dynamic analysis of mooring system, research on performance of turret assembly, influence of vessel dimensions and hull forms on mooring performance, model tests under combined action of environmental forces in basin, and hull structural strength analysis.
文摘In the process of the constant development of the oil and gas storage and transportation technology, the maintenance of the large pipelines is an important task. At present, China vigorously promotes the use of the pipeline robots, for the maintenance of the oil and gas pipelines by the unique characteristics of the robots. In this paper, the author carries out the detailed analysis on the current situation of the development of the pipeline robots in the oil and gas storage and transportation industry, and compares the different applications of the pipeline robots at home and abroad. Starting from the principles of the operation of the robots, the author analyzes the characteristics of the different types of the robots, and combined with the existing conditions of the oil and gas storage and transportation in our country, the author tries to find the most favorable way of the working of the pipeline robots, to continuously improve the development of the oil and gas storage and transportation industry using the robot technologies.
文摘In recent years, our country is increasingly dependent on the use of the oil resources, and the degree of the oil mining is also continuously upgrading. After the completion of the tasks related to the oil mining in the lands, the technologies for the development of the offshore oil mining are particularly important. Among these problems, after the exploitation, the storage and transportation of the offshore oil and gas is worthy of the discussion of the technical personnel. From the experience of the oil and gas storage and transportation in the long years, in some environmentally degraded areas, there are problems in the efficiency and safety in the long pipeline transportation and the oil and gas mixed transportation, and in the transportation, there are also big shortcomings. In this paper, the author carries on the analysis of the existing questions encountering in our country＇s oil and gas storage and transportation~ and proposes the direction of the researches in the future oil and gas storage and transportation, and the purpose is to better improve the security of Cbina＇s oil and gas storage and transportation and to enhance the efficiency of the use of the oil and gas.
文摘Oil is an important resource for a country's development, which involves many aspects of social development. It is also an important pillar of economic development and promotes the all-round development of society. In the current era, people's demand for oil resources is gradually increasing, which leads to the prominent importance of oil and gas storage and transportation equipment management. The industry needs to optimize according to the actual situation at this stage, clarify the new situation of development, integrate existing resources and create a new development system, so as to improve the overall security and adapt to the development of the times.
文摘In recent years,the safety of oil and gas storage and transportation facilities has been paid more attention by the state and enterprises due to frequent accidents.The oil and gas storage and transportation facilities safety courses in China University of Petroleum(Beijing)includes“Engineering mechanics”,“Strength design of pipelines and tanks”and“Safety and integrity management of oil and gas storage and transportation facilities”.The three courses lack relevance and the teaching mode is too rigid,resulting in students losing their initiative in learning.If students can’t use the knowledge flexibly,it will affect the achievement of the objectives of the training program.Therefore,oil and gas storage and transportation facilities safety courses are reformed,training plans are adjusted and teaching methods are improved.The practice shows that the reform enriches the teaching content,improves the teaching quality,stimulates classroom activity and gets a good evaluation of students.The reform of safety courses has a certain significance for cultivating compound talents who have the ability to solve practical problems in engineering.
文摘Oil and gas can be stored underground by a variety of means,such as in depleted oil and gas fields,in aquifers,in rock salt caverns,in unlined mined rock caverns,in lined shallow caverns and abandoned mines.Different types of underground storages require different geological and hydrogeological conditions and are associated with different rock engineering problems.However,the common issue is to ensure the gas-and oil-tightness of storage caverns.In other words,the stored oil and gas must not escape from the storage caverns.This may be realized by different means according to the types of storages and the sites geological conditions.There are basically two approaches of gas leakage control,i.e.permeability control and hydrodynamic containment.The latter involves the use of a water curtain system in many cases,which creates an artificial hydraulic boundary condition and helps to establish the required groundwater condition when needed.In addition to the common problems,the underground storage of liquefied petroleum gas(LPG) requires special attentions to the opening of rock joints,which result from the tensile thermal stress induced by the low storage temperature.Great care must be taken in choosing abandoned mines for oil and gas-storage since it is quite rare that the natural site conditions can meet the usual requirements,in particular for the gas tightness.The paper provides a general description of the gas leakage control for underground oil and gas storage projects,and addresses various rock engineering problems associated with selected types of storages in detail.
基金This work was financially supported by National Natural Science Foundation of China(91858208,41406080,42076069)China Geological Survey(DD20190581).
文摘Oil and gas resources are short in Pakistan and no commercially viable oil and gas sources have been yet discovered in its offshore areas up to now.In this study,the onshore-offshore stratigraphic correlation and seismic data interpretation were conducted to determine the oil and gas resource potential in the Offshore Indus Basin,Pakistan.Based on the comprehensive analysis of the results and previous data,it is considered that the Cretaceous may widely exist and three sets of source rocks may be developed in the Offshore Indus Basin.The presence of Miocene mudstones has been proven by drilling to be high-quality source rocks,while the Cretaceous and Paleocene–Eocene mudstones are potential source rocks.Tectonic-lithologic traps are developed in the northwestern part of the basin affected by the strike-slip faults along Murray Ridge.Furthermore,the Cretaceous and Paleocene–Eocene source rocks are thick and are slightly affected by volcanic activities.Therefore,it can be inferred that the northwestern part of Offshore Indus Basin enjoys good prospects of oil and gas resources.
基金supported by the National Natural Science Foundation of China(Grant No.52004030)the R&D Program of Beijing Municipal Education Commission(Grant No.KM202310016003)the Exchange Program of High-end Foreign Experts of Ministry of Science and Technology,China(Grant No.G2022178013L)。
文摘Accidents in engineered systems are usually generated by complex socio-technical factors.It is beneficial to investigate the increasing complexity and coupling of these factors from the perspective of system safety.Based on system and control theories,System-Theoretic Accident Model and Processes(STAMP)is a widely recognized approach for accident analysis.In this paper,we propose a STAMP-Game model to analyze accidents in oil and gas storage and transportation systems.Stakeholders in accident analysis by STAMP can be regarded as players of a game.Game theory can,thus,be adopted in accident analysis to depict the competition and cooperation between stakeholders.Subsequently,we established a game model to study the strategies of both supervisory and supervised entities.The obtained results demonstrate that the proposed game model allows for identifying the effectiveness deficiency of the supervisory entity,and the safety and protection altitudes of the supervised entity.The STAMP-Game model can generate quantitative parameters for supporting the behavior and strategy selections of the supervisory and supervised entities.The quantitative data obtained can be used to guide the safety improvement,to reduce the costs of safety regulation violation and accident risk.
基金financially supported by the National Science Foundation of China(Nos.41830431,41672139)thirteenth research plan of the Ministry of Science and Technology of China(Nos.2017ZX05049005-007,2016ZX05034002-003)。
文摘The amount of shale oil and its characterization are key issues in the study of shale oil.At present,many scholars use a variety of methods to evaluate the amount of shale oil,and use the calculated amount of hydrocarbons to analyze its influencing factors;however,there is lack of detailed research on the storage space for shale-oil and it’s influencing factors.In view of this issue,gas chromatography(GC),gas chromatography-mass spectrometry(GC-MS),soxhlet extraction(SE),fieldemission scanning electron microscopy(FE-SEM),low-temperature nitrogen adsorption(LTNA),highpressure mercury intrusion(HPMI),and X-ray diffraction(XRD)were used to analyze and compare samples from two wells located in different deposition locations.The unconventional Well BYY2 and BX7 s were drilled in the depocenter and distal area of the Qianjiang Formation,respectively.Controlled by differences in the organic matter type and sedimentary environment,the organic matter in Well BYY2,which was found to be characterized by laminar shale,mainly originated from aquatic algae.The results showed that as the total organic carbon(TOC)content increased,the amount of shaleoil in the pores increased.Shale-oil was mostly stored in mesopores and macropores that had been preserved by dolomite minerals of a biogenic origin and also occurred in pores sized 5–200 nm and>1μm.Dolomite minerals of a biogenic origin and clay minerals contributed to the occurrence of shaleoil.In comparison,the organic matter in Well BX7 has been greatly influenced by terrestrial organic matter.Pores in the massive mudstones from Well BX7 were determined to be mainly mesopores preserved by clay minerals and quartz,and the shale-oil was mostly stored within the pores of<40 nm.When the TOC content was~2.5 wt.%,the generated shale-oil reached saturation.Clay minerals contributed to the occurrence of shale-oil,whereas quartz only contributed to the occurrence of shale-oil in macropores.
基金Project supported by the Scientific Research&Technical Development Project of PetroChina Company Limited“Research and application of key technologies for geology and gas reservoir engineering of underground gas storage”(No.2015E-400201).
文摘Whole-life-cycle integrity management of underground gas storages(UGSs)has been an important link to ensure its long-term safe and efficient operation.At present,the integrity of UGSs in oil/gasfields and its evaluation techniques focus on surface facilities and injection/withdrawal wells,but its geological integrity lacks clear definition and evaluation object and systematic evaluation techniques.In this paper,relevant research achievements werefirstly summarized.Then,the concept of geological integrity with the gas-storage geological body as the evaluation object was put forward,and the evaluation system for the geological integrity of such UGSs was established.Finally,UGS geological integrity evaluation was carried out with the Hutubi Underground Gas Storage in Xinjiang as an example.And the following research results were obtained.First,UGS geological integrity is defined as the integrity degree of each component of a gas-storage geological body to meet operation requirements and fulfill seasonal and emergency peak shaving safely and economically during the operation of a UGS.Its connotation is that reservoir of geological body,caprock,fault and trap can supply the customers with gas continuously and stably and ensure the safe operation of the UGS in its service life.And its core lies in keeping the reliability,safety and economy of natural gas storage in the service life of a UGS.Second,the geological integrity evaluation system is composed of four evaluation techniques,including trap effectiveness,caprock integrity,fault stability and reservoir stability.Third,the evaluation results show that the Hutubi Underground Gas Storage has the potential of peak-shaving capacity enhancement by increasing the maximum operation pressure.In conclusion,the establishment of the geological integrity evaluation system for such UGSs improves the UGS integrity evaluation technique system and plays an instructive and practical role in ensuring the long-term safe and efficient operation of UGSs,increasing the maximum operation pressure and improving the peak shaving capacity.
文摘This project investigated the potential optimal development strategy for a saturated reservoir, with a gas cap. It assessed the viability of three production methods—solution gas drive (primary depletion), water flooding and gas injection, using varying injector well numbers. This project also undertook sensitivity analysis in the field, concluding that the development of another appraisal well would vastly improve the accuracy of NPV calculation. Furthermore, this project ascertained an optimized recovery method, based on numerical production simulations and economic modelling, of initial solution gas drive recovery, until reservoir pressure equals the bubble point pressure, at which point three water flooding injectors should be employed, developed at six-month intervals to maximise production while limiting CAPEX and OPEX as much as possible.
