Carbon capture and storage(CCS)remains one of the most feasible techniques for the control of Greenhouse gas emission levels.However,there will always be risks attached to the subsurface injection of CO_(2).These coul...Carbon capture and storage(CCS)remains one of the most feasible techniques for the control of Greenhouse gas emission levels.However,there will always be risks attached to the subsurface injection of CO_(2).These could be in the form of leakages from the injection wellbore due to completion failure;escape of the injected CO_(2)to neighboring aquifers due to the heterogeneous or fractured nature of the storage site;or seepage at the surface due to inadequacy of the sealing cap rock.While all these may occur,the most cost-effective and timely way to reduce the risk of leakages is by plugging the pathways.This is done using either traditional Cementous materials or more augmented sealants like organic gels and resins.A lot of studies in the literature have described this collection of materials within the context of CO_(2)conformance control.So also,there are reviews on the classification and description of these chemicals.This review provides a more systemic evaluation of these classes of chemicals.This is by providing critical analyses of how external factors like CO_(2),pH,brine salinity and hardness,rock mineralogy,pressure,temperature,and injectivity could affect the performance of different sealants that can be utilized.Based on these assessments,best practices for the application of the sealants,both at the testing stage in the laboratory and the pilot stage and field deployment,are suggested.展开更多
This paper provides an introduction to the topic of water shutoff and conformance improvement. After indicating the volumes of water produced during oilfield operations, a strategy is provided for attacking excess wat...This paper provides an introduction to the topic of water shutoff and conformance improvement. After indicating the volumes of water produced during oilfield operations, a strategy is provided for attacking excess water production problems. Problem types are categorized, typical methods of problem diagnosis are mentioned, and the range of solutions is introduced for each problem type. In the third section of the paper, the concept of disproportionate permeability reduction is introduced—where polymers and gels may reduce permeability to water more than to oil or gas. When and where this property is of value is discussed. The fourth section describes the properties of formed gels as they extrude through fractures and how those properties can be of value when treating conformance problems caused by fractures. Section 5 covers the efficiency with which gels block fractures after gel placement—especially, the impact of fluids injected subsequent to the gel treatment.展开更多
Excess water production has become an important issue in the oil and gas extraction process.Preformed particle gels(PPGs),show the capability to control the conformance and reduce excess water cut.However,conventional...Excess water production has become an important issue in the oil and gas extraction process.Preformed particle gels(PPGs),show the capability to control the conformance and reduce excess water cut.However,conventional PPGs have poor mechanical properties and their swollen particles are easily damaged by shearing force when passing through the fractures in formations,meanwhile PPGs can be also degraded into various byproducts,leading to permanent damage to the reservoir permeability after temporary plugging.Herein,a novel type of dual cross-linked PPGs(dPPGs)was designed and synthesized using sodium alginate(SA)and acrylamide(AAm),cross-linked with N,N’-methylenebisacrylamide(MBA)and Fe^(3+).Results show that dPPGs have excellent mechanical properties with a storage modulus up to 86,445 Pa,which is almost 20 times higher than other reported PPGs.Meanwhile,dPPGs can be completely degraded into liquid without any solid residues or byproducts and the viscosity of dPPGs degraded liquid was found to be lower than 5 mPa·s.A laboratory coreflooding test showed that the plugging efficiency of dPPGs was up to 99.83%on open fractures.The obtained results demonstrated that dPPGs could be used as economical and environment-friendly temporary plugging agent with high-strength,self-degradation,thermal stability,and salt stability,thus making it applicable to a wide range of conformance control to enhance oil recovery.展开更多
Injecting CO_(2)into the underground for oil displacement and shortage is an important technique for carbon capture,utilization and storage(CCUS).One of the main problems during the CO_(2)injection is the channeling p...Injecting CO_(2)into the underground for oil displacement and shortage is an important technique for carbon capture,utilization and storage(CCUS).One of the main problems during the CO_(2)injection is the channeling plugging.Finding an effective method for the gas channeling plugging is a critical issue in the CO_(2)EOR process.In this work,an acid-resistance microgel named dispersed particle gel(DPG)was characterized and its stability was tested in the CO_(2)environment.The microgel size selection strategies for the homogeneous and heterogeneous reservoirs were respectively investigated using the single core flooding and three parallel core flooding experiments.Moreover,the comparison of microgel alternate CO_(2)(MAC)injection and water alternate CO_(2)(WAC)injection in the dual core flooding experiments were presented for the investigation of the role of microgel on the conformance control in CO_(2)flooding process.The results have shown that the microgel featured with ANH and CAN groups can keep its morphology after aging 7 days in the CO_(2)environment.Where,the small microgel with unobstructed migration and large microgel with good plugging efficiency for the high permeability zone were respectively featured with the higher recovery factor in homogeneous and heterogeneous conditions,which indicate they are preferred used for the oil displacement and conformance control.Compared to WAC injection,MAC injection had a higher incremental recovery factor of 12.4%.It suggests the acid-resistance microgel would be a good candidate for the conformance control during CO_(2)flooding process.展开更多
Injecting CO2into hydrocarbon reservoirs can enhance the recovery of hydrocarbon resources,and simultaneously,CO2can be stored in the rese rvoirs,reducing considerable amount of carbon emissions in the atmosphere.Howe...Injecting CO2into hydrocarbon reservoirs can enhance the recovery of hydrocarbon resources,and simultaneously,CO2can be stored in the rese rvoirs,reducing considerable amount of carbon emissions in the atmosphere.However,injected CO_(2)tends to go through fractures,high-permeability channels and streaks present in reservoirs,resulting in inefficient hydrocarbon recovery coupled with low CO_(2)storage performance.Conformance treatments with CO_(2)-resistant crosslinked polymer gels were performed in this study to mitigate the CO_(2)channeling issue and promote the synergy between enhanced oil recovery(EOR) and subsurface sequestration of CO_(2).Based on a typical low-permeability CO_(2)-flooding reservoir in China,studies were performed to investigate the EOR and CO_(2)storage performance with and without conformance treatment.The effect of permeability contrast between the channels and rese rvoir matrices,treatment size,and plugging strength on the efficiency of oil recovery and CO_(2)storage was systematically investigated.The results indicated that after conformance treatments,the CO_(2)channeling problem was mitigated during CO_(2)flooding and storage.The injected CO_(2)was more effectively utilized to recover the hydrocarbons,and entered wider spectrum of pore spaces.Consequently,more CO_(2)was trapped underground.Pronounced factors on the synergy of EOR and CO_(2)storage were figured out.Compared with the treatment size,the CO_(2)storage efficiency was more sensitive to the plugging strength of the conformance treatment materials.This observation was important for conformance treatment design in CCUS-EOR projects.According to this study,the materials should reduce the channel permeability to make the channel/matrix permeability ratio below 30.The results demonstrate the importance of conformance treatment in maximizing the performance of CCUS-EOR process to achieve both oil recovery improvement and efficient carbon storage.This study provides guidelines for successful field applications of CO_(2)transport control in CO_(2)geo-utilization and storage.展开更多
Plugging agents have been widely used to enhance oil recovery in fractured-vuggy carbonate reservoirs.However,the harsh conditions of fractured-vuggy carbonate reservoirs yield a significant challenge in maintaining a...Plugging agents have been widely used to enhance oil recovery in fractured-vuggy carbonate reservoirs.However,the harsh conditions of fractured-vuggy carbonate reservoirs yield a significant challenge in maintaining a long-term stabilization of plugging agents.In this work,we developed an anti-hightemperature and high-salinity polymer gel(APG)with excellent resistance to high temperature(140℃)and ultra-high salinity(240000 mg/L).The rheology and microstructure of APG were characterized before and after gelation.Core plugging tests on fractured cubic cores were conducted to quantify the plugging performance of the gel system.Experimental results showed that the Sclerglucan and Cobalt(Ⅱ)Chloride Hexahydrate filled the three-dimensional(3-D)network with various morphologies,providing extra protection to the cross-linking points of the 3D network structure of APG and thus,leading to a prolongation of the dehydration time.The dehydration rate of APG was only 5%within 30days,and the strength of APG could be maintained at a rigid or near-rigid level over 150 days.Moreover,APG exhibited satisfactory shear and scour resistance.Core plugging tests showed that APG could achieve a plugging rate of 90%and demonstrate ignorable minor damage to the substrate.Our results indicate that APG can serve as a great candidate in channel plugging in fractured-vuggy carbonate reservoirs where fractures are fully developed.展开更多
Polymer gel systems have been widely applied to control excessive water and improve oil recovery(IOR)in petroleum reservoirs.They are usually divided into two main types,in-situ cross-linked polymer gels,and pre-forme...Polymer gel systems have been widely applied to control excessive water and improve oil recovery(IOR)in petroleum reservoirs.They are usually divided into two main types,in-situ cross-linked polymer gels,and pre-formed polymer gels.In recent years,nuclear magnetic resonance(NMR) technology has been gradually applied to the research of polymer gel systems due to its unique analysis advantages.This paper is intent to review these works systematically.For in-situ cross-linked polymer gel systems,NMR can be used to characterize the chemical structure changes of the polymer,the cross-linker,and the auxiliary agent in the formulation of the polymer gel systems.Moreover,the gelation time and the gel strength of the in-situ cross-linked polymer gel systems can also be measured by NMR.For pre-formed polymer gels,NMR can be employed to detect the chemical structure of the designed products.Last,the NMR method can evaluate the plugging,water control,and oil improvement performance of the polymer gels in porous media without using dopants.This review can help readers build a more systematic understanding of the application of NMR technology in polymer gel systems for IOR and help re searchers to more deeply study the performance of polymer gel systems.展开更多
Micro-scale and nano-scale dispersed gel particles(DPG)are capable of deep migration in oil reservoirs due to their deformability,viscoelasticity,and suitable particle size.Therefore,it has been widely studied and app...Micro-scale and nano-scale dispersed gel particles(DPG)are capable of deep migration in oil reservoirs due to their deformability,viscoelasticity,and suitable particle size.Therefore,it has been widely studied and applied in reservoir conformance control in recent years.However,for highly permeable channels,their plugging performance is still limited.In addition,conventional in situ cross-linked polymer gels(ISCPGs)have fast gelation time under extremely high-temperature conditions,which often causes problems such as difficulty in pumping.Therefore,a re-cross linkable dispersed particle gel(RDPG)system applied for conformance control in highly permeable channels of extremely high-temperature petroleum reservoirs was investigated.The particle size distribution,gelation time,gel strength,injection performance,and perfo rmance strength in po rous media were investigated using a laser particle size meter,the Sydansk bottle test method,rheometer,and core displacement experiments,respectively.Results show that the RDPG suspension can be stable for more than 6 months at room temperature with storage modulus G’much lower than 10 Pa.It can pass through the pore throat by elastic deformation effect and does not cause strong blockage.Moreover,it can undergo re-crosslinking reaction at 150℃to form a strong bulk gel.The gel strength G’of re-crosslinked RDPG can be as high as 69.3 Pa,which meets the strength requirement of conformance control.The RDPG suspension has the properties of easy injection,and it also has strong plugging,and high-temperature resistance after re-crosslinked in the core,which can be a very promising material for conformance improvement in extremely high-temperature reservoirs.展开更多
Microscopic computed tomography(Micro-CT)is used to visualize microscopic flow in sandstone core samples during emulsion flooding.The images obtained during the experiment are processed quantitatively with a series of...Microscopic computed tomography(Micro-CT)is used to visualize microscopic flow in sandstone core samples during emulsion flooding.The images obtained during the experiment are processed quantitatively with a series of methods to evaluate the occurrence characteristics and oil recovery enhancement mechanisms of emulsion.(1)The emulsion is distributed in the cores in spherical shape,and its sphericity is significantly different from that of the remaining oil.Sphericity can be taken as a characteristic parameter to identify emulsion.(2)The emulsion with specific size prefers to stay in pores with matching sizes;when the emulsion volume is smaller than the product of the lower limit of pore occupancy and the corresponding pore vol-ume,it will not be able to effectively trap in the pore to achieve conformance control.In the process of emulsion displacement designing,we need to design emulsion with suitable particle size according to the pore distribution of the reservoir.(3)Mobi-lization ratio of the pores can be increased from 23.1%to 59.3%by emulsion flooding after subsequent water flooding,and the average oil displacement efficiency at the pore-scale can be increased from 22.9%to 75.8%under the test conditions;(4)After emulsion flooding,the clustered remaining oil and the oil phase in the trapped emulsion are the main targets for further EOR.展开更多
Globally, traditional power systems are rapidly transforming towards the adoption of smart grid platforms. Substations which are at the center of the electric power transformation from the power plant are changing to ...Globally, traditional power systems are rapidly transforming towards the adoption of smart grid platforms. Substations which are at the center of the electric power transformation from the power plant are changing to IEC 61850 based digital substations. Therefore, within substation, there is a growing demand for the IEC 61850 based Intelligent Electronic Devices (IEDs). The operation of multiple manufacturers of IEDs in a single digital substation network increases the need for IEC 61850 communications specification conformance diagnosis to ensure interoperability for efficient data exchange between IEDs. The IEC 61850-10 presents test items for diagnosing communication specification conformance. There are many test tools available in the market today to test the compliance of the IEC 61850 communications specifications to the IED. In this paper, we propose a model-based diagnostic method for IED communication conformance testing. The proposed model-based software therefore uses the “drag and drop” technique to select the various IEC 61850 communication services (objects) required to design the test case in a user friendly Graphical User Interface (GUI). This makes the service conformance testing more flexible for test engineers and system integrators especially in situations that require test case modifications. Also, the proposed software tool makes it easy to understand the various IEC 61850 services using the friendly GUI.展开更多
This paper describes the ISUP (ISDN User Part of CCSS7) conformance testing theory and method according to CCITT and China national standards, and presents a successful ISUP protocol conformance testing system in detail.
In this paper, a conformance test platform is built for intelligent electronic devices (IEDs) from different manufacturers based on IEC 61850 communication protocol. A conformance test of time delay of message transmi...In this paper, a conformance test platform is built for intelligent electronic devices (IEDs) from different manufacturers based on IEC 61850 communication protocol. A conformance test of time delay of message transmission between two IEDs, made by the same or different manufacturers, is performed. The conformance test platform, as well as the test results provide a helpful reference for IEC 61850 implementation.展开更多
19 November 2013,Shenzhen-ZTE Corporation has announced that ZTE＇s ZSmart BSS/OSS V8 has successfully achieved TM Forum＇s Frameworx 12.0 Conformance Certification.TM Forum＇s Frameworx Conformance Certification is a...19 November 2013,Shenzhen-ZTE Corporation has announced that ZTE＇s ZSmart BSS/OSS V8 has successfully achieved TM Forum＇s Frameworx 12.0 Conformance Certification.TM Forum＇s Frameworx Conformance Certification is an independent verification of how a solution＇s business processes and information models align with the industry standards found in Frameworx,including the Business Process Framework（eTOM）and Information Framework（SID）.展开更多
The session initiation protocol (SIP) is a signaling protocol for Internet telephony, multimedia conferencing, presence, event notification, and instant messaging. With the gaining popularity, more and more SIP implem...The session initiation protocol (SIP) is a signaling protocol for Internet telephony, multimedia conferencing, presence, event notification, and instant messaging. With the gaining popularity, more and more SIP implementations have been developed and deployed. How to guarantee the conformance of those SIP implementations is the key point of interconnection and interoperation among them. This paper proposes the test method and architecture for the SIP protocol based on the IPv6 tester system. Tree and tabular combined notation (TTCN-2) is adopted to describe the test suite. With an enhanced reference implementation, the data-processing ability to the original test system has been greatly improved. In the following test practices, some errors have been found in the SIP entities under test. It is proved that the proposed test method and architecture are effective to verify the conformance of the SIP entities, and the result of the conformance test may provide helpful reference to the development of SIP products.展开更多
We present a method of generating test cases from the software specifications which are modeled by nondeterministic finite state machines. It is applicable to both nondeterministic and deterministic finite state mach...We present a method of generating test cases from the software specifications which are modeled by nondeterministic finite state machines. It is applicable to both nondeterministic and deterministic finite state machines. When applied to deterministic machines, this method yields usually smaller test suites with full fault coverage than the existing methods that also assure full fault coverage. In particular, the proposed mehod can be used to test the control portion of software specified in the formalspecification languages SDL or ESTELLE.展开更多
As cloud computing technology turning to mature,cloud services have become a trust-based service.Users'distrust of the security and performance of cloud services will hinder the rapid deployment and development of...As cloud computing technology turning to mature,cloud services have become a trust-based service.Users'distrust of the security and performance of cloud services will hinder the rapid deployment and development of cloud services.So cloud service providers(CSPs)urgently need a way to prove that the infrastructure and the behavior of cloud services they provided can be trusted.The challenge here is how to construct a novel framework that can effective verify the security conformance of cloud services,which focuses on fine-grained descriptions of cloud service behavior and security service level aggreements(SLAs).In this paper,we propose a novel approach to verify cloud service security conformance,which reduces the description gap between the CSP and users through modeling cloud service behavior and security SLA,these models enable a systematic integration of security constraints and service behavior into cloud while using UPPAAL to check the performance and security conformance.The proposed approach is validated through case study and experiments with real cloud service based on Open-Stack,which illustrates CloudSec approach effectiveness and can be applied on realistic cloud scenario.展开更多
Conformance control or water shut-off is a technique used to improve oil recovery.During conformance control,polymers block high permeability water areas and redistribute water drive toward unswept oil zones.In this s...Conformance control or water shut-off is a technique used to improve oil recovery.During conformance control,polymers block high permeability water areas and redistribute water drive toward unswept oil zones.In this study,co-polymers(denoted ATP-PGV/AM-co-AMPS)were synthesized using acrylamide(AM)and 2-acrylamide-2-methylpropane sulfonic acid(AMPS)as the monomers,polyethylene glycol(PEG)-200 and methylenebisacrylamide(MBA)as the crosslinkers,attapulgite(ATP)and bentonite(PGV)as the clay types,and ammonium persulfate(APS)as the initiator,in addition to paraffin oil and surfactants.Samples were synthesized using inverse emulsion polymerization with different concentrations of monomers,crosslinkers,and clays,and they were characterized using Fourier-transform infrared(FTIR)spectroscopy and scanning electron microscopy(SEM)with energy dispersive X-ray spectroscopy(EDX).FTIR spectra of the samples confirmed the existence of sulfonate and hydroxyl groups,which are important for polymer swelling.SEM-EDX images indicated that the morphology and elemental composition were different before and after swelling,confirming the occurrence of swelling.Moreover,samples were placed in sodium chloride solution(20,000 ppm)for 7 days to evaluate swelling at both room temperature and 90°C.Thermogravimetric analysis(TGA)and differential scanning calorimetry(DSC)were used to determine the thermal characteristics of the microparticles.Finally,rheological measurements were used to assess the deformation and rheological behavior of the hydrogels.The results showed that after 1 day,good swelling without loss of mechanical strength was achieved with the composite synthesized using 10%AM,15%AMPS,6%PGV,and 10%ATP.展开更多
Exchanging simulation models is currently of utmost importance.To improve interoperability between suppliers and original equipment manufacturers(OEMs),the functional mock-up interface(FMI)is exchanged in a standard f...Exchanging simulation models is currently of utmost importance.To improve interoperability between suppliers and original equipment manufacturers(OEMs),the functional mock-up interface(FMI)is exchanged in a standard format called functional mock-up unit(FMU).Since its first release,many simulation tools took the initiative to support FMI.However,since then,there have been many complaints stating that exchanging models via FMI does not work as stable as expected.The reason usually turned out to be the implementation of tool vendors that sometimes fail to comply with the standard fully.This paper introduces a methodology for testing FMI compliance of importing simulation tools using a set of reference FMUs.The standard defines the implementation of FMI functions calling sequence in a state machine.Therefore,conformance testing(also called fault detection)from automata theory is utilized to produce reference FMUs based on the FMI state-machine.展开更多
基金Ministry of Science and Higher Education of the Russian Federation,Grant/Award Number:FSNM-2024-0005Korea Institute of Energy Technology Evaluation and Planning,Grant/Award Number:20225B10300080Yayasan UTP,Grant/Award Number:015LC0-526。
文摘Carbon capture and storage(CCS)remains one of the most feasible techniques for the control of Greenhouse gas emission levels.However,there will always be risks attached to the subsurface injection of CO_(2).These could be in the form of leakages from the injection wellbore due to completion failure;escape of the injected CO_(2)to neighboring aquifers due to the heterogeneous or fractured nature of the storage site;or seepage at the surface due to inadequacy of the sealing cap rock.While all these may occur,the most cost-effective and timely way to reduce the risk of leakages is by plugging the pathways.This is done using either traditional Cementous materials or more augmented sealants like organic gels and resins.A lot of studies in the literature have described this collection of materials within the context of CO_(2)conformance control.So also,there are reviews on the classification and description of these chemicals.This review provides a more systemic evaluation of these classes of chemicals.This is by providing critical analyses of how external factors like CO_(2),pH,brine salinity and hardness,rock mineralogy,pressure,temperature,and injectivity could affect the performance of different sealants that can be utilized.Based on these assessments,best practices for the application of the sealants,both at the testing stage in the laboratory and the pilot stage and field deployment,are suggested.
文摘This paper provides an introduction to the topic of water shutoff and conformance improvement. After indicating the volumes of water produced during oilfield operations, a strategy is provided for attacking excess water production problems. Problem types are categorized, typical methods of problem diagnosis are mentioned, and the range of solutions is introduced for each problem type. In the third section of the paper, the concept of disproportionate permeability reduction is introduced—where polymers and gels may reduce permeability to water more than to oil or gas. When and where this property is of value is discussed. The fourth section describes the properties of formed gels as they extrude through fractures and how those properties can be of value when treating conformance problems caused by fractures. Section 5 covers the efficiency with which gels block fractures after gel placement—especially, the impact of fluids injected subsequent to the gel treatment.
基金supported by Shanxi Provincial Key Research and Development Project(No.20201102002)the Science Foundation of China University of Petroleum,Beijing(No.2462020BJRC007,2462020YXZZ003)State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum(No.PRP/DX-2216)
文摘Excess water production has become an important issue in the oil and gas extraction process.Preformed particle gels(PPGs),show the capability to control the conformance and reduce excess water cut.However,conventional PPGs have poor mechanical properties and their swollen particles are easily damaged by shearing force when passing through the fractures in formations,meanwhile PPGs can be also degraded into various byproducts,leading to permanent damage to the reservoir permeability after temporary plugging.Herein,a novel type of dual cross-linked PPGs(dPPGs)was designed and synthesized using sodium alginate(SA)and acrylamide(AAm),cross-linked with N,N’-methylenebisacrylamide(MBA)and Fe^(3+).Results show that dPPGs have excellent mechanical properties with a storage modulus up to 86,445 Pa,which is almost 20 times higher than other reported PPGs.Meanwhile,dPPGs can be completely degraded into liquid without any solid residues or byproducts and the viscosity of dPPGs degraded liquid was found to be lower than 5 mPa·s.A laboratory coreflooding test showed that the plugging efficiency of dPPGs was up to 99.83%on open fractures.The obtained results demonstrated that dPPGs could be used as economical and environment-friendly temporary plugging agent with high-strength,self-degradation,thermal stability,and salt stability,thus making it applicable to a wide range of conformance control to enhance oil recovery.
基金supported by the National Natural Science Foundation of China(52004305)the Postdoctoral Research Foundation of China(2021M693497)the Science Foundation of China University of Petroleum,Beijing(2462020XKBH006)。
文摘Injecting CO_(2)into the underground for oil displacement and shortage is an important technique for carbon capture,utilization and storage(CCUS).One of the main problems during the CO_(2)injection is the channeling plugging.Finding an effective method for the gas channeling plugging is a critical issue in the CO_(2)EOR process.In this work,an acid-resistance microgel named dispersed particle gel(DPG)was characterized and its stability was tested in the CO_(2)environment.The microgel size selection strategies for the homogeneous and heterogeneous reservoirs were respectively investigated using the single core flooding and three parallel core flooding experiments.Moreover,the comparison of microgel alternate CO_(2)(MAC)injection and water alternate CO_(2)(WAC)injection in the dual core flooding experiments were presented for the investigation of the role of microgel on the conformance control in CO_(2)flooding process.The results have shown that the microgel featured with ANH and CAN groups can keep its morphology after aging 7 days in the CO_(2)environment.Where,the small microgel with unobstructed migration and large microgel with good plugging efficiency for the high permeability zone were respectively featured with the higher recovery factor in homogeneous and heterogeneous conditions,which indicate they are preferred used for the oil displacement and conformance control.Compared to WAC injection,MAC injection had a higher incremental recovery factor of 12.4%.It suggests the acid-resistance microgel would be a good candidate for the conformance control during CO_(2)flooding process.
基金supported by Science Foundation of China University of Petroleum,Beijing(No.2462022BJRC001,2462021YJRC012)the funding from State Key Laboratory of Petroleum Resources and Prospecting(No.PRP/indep-1-2103)
文摘Injecting CO2into hydrocarbon reservoirs can enhance the recovery of hydrocarbon resources,and simultaneously,CO2can be stored in the rese rvoirs,reducing considerable amount of carbon emissions in the atmosphere.However,injected CO_(2)tends to go through fractures,high-permeability channels and streaks present in reservoirs,resulting in inefficient hydrocarbon recovery coupled with low CO_(2)storage performance.Conformance treatments with CO_(2)-resistant crosslinked polymer gels were performed in this study to mitigate the CO_(2)channeling issue and promote the synergy between enhanced oil recovery(EOR) and subsurface sequestration of CO_(2).Based on a typical low-permeability CO_(2)-flooding reservoir in China,studies were performed to investigate the EOR and CO_(2)storage performance with and without conformance treatment.The effect of permeability contrast between the channels and rese rvoir matrices,treatment size,and plugging strength on the efficiency of oil recovery and CO_(2)storage was systematically investigated.The results indicated that after conformance treatments,the CO_(2)channeling problem was mitigated during CO_(2)flooding and storage.The injected CO_(2)was more effectively utilized to recover the hydrocarbons,and entered wider spectrum of pore spaces.Consequently,more CO_(2)was trapped underground.Pronounced factors on the synergy of EOR and CO_(2)storage were figured out.Compared with the treatment size,the CO_(2)storage efficiency was more sensitive to the plugging strength of the conformance treatment materials.This observation was important for conformance treatment design in CCUS-EOR projects.According to this study,the materials should reduce the channel permeability to make the channel/matrix permeability ratio below 30.The results demonstrate the importance of conformance treatment in maximizing the performance of CCUS-EOR process to achieve both oil recovery improvement and efficient carbon storage.This study provides guidelines for successful field applications of CO_(2)transport control in CO_(2)geo-utilization and storage.
基金financial support of the Science Foundation of China University of Petroleum,Beijing(Grant No.2462020XKBH013)The Science Foundation of China University of Petroleum,Beijing(Grant No.2462017YJRC037)+1 种基金Sponsored by CNPC Innovation Found(Grant No.2021DQ02-0202)Horizontal project of Sinopec Northwest Oilfield Company(Grant No.202108ZB0046)are also significantly acknowledged
文摘Plugging agents have been widely used to enhance oil recovery in fractured-vuggy carbonate reservoirs.However,the harsh conditions of fractured-vuggy carbonate reservoirs yield a significant challenge in maintaining a long-term stabilization of plugging agents.In this work,we developed an anti-hightemperature and high-salinity polymer gel(APG)with excellent resistance to high temperature(140℃)and ultra-high salinity(240000 mg/L).The rheology and microstructure of APG were characterized before and after gelation.Core plugging tests on fractured cubic cores were conducted to quantify the plugging performance of the gel system.Experimental results showed that the Sclerglucan and Cobalt(Ⅱ)Chloride Hexahydrate filled the three-dimensional(3-D)network with various morphologies,providing extra protection to the cross-linking points of the 3D network structure of APG and thus,leading to a prolongation of the dehydration time.The dehydration rate of APG was only 5%within 30days,and the strength of APG could be maintained at a rigid or near-rigid level over 150 days.Moreover,APG exhibited satisfactory shear and scour resistance.Core plugging tests showed that APG could achieve a plugging rate of 90%and demonstrate ignorable minor damage to the substrate.Our results indicate that APG can serve as a great candidate in channel plugging in fractured-vuggy carbonate reservoirs where fractures are fully developed.
基金supported by the Research Foundation of China University of Petroleum-Beijing at Karamay (No. XQZX20200010)the Natural Science Foundation of Xinjiang Uygur Autonomous Region (No. 2019D01B57)+3 种基金the Tianshan Talent Project (No. 2019Q025)the Sichuan Province Regional Innovation Cooperation Project (No. 2020YFQ0036)the Science and Technology Department of Shaanxi Province (No. 2021JQ-836)the CNPC Strategic Cooperation Science and Technology Project (ZLZX2020-01-04-04)。
文摘Polymer gel systems have been widely applied to control excessive water and improve oil recovery(IOR)in petroleum reservoirs.They are usually divided into two main types,in-situ cross-linked polymer gels,and pre-formed polymer gels.In recent years,nuclear magnetic resonance(NMR) technology has been gradually applied to the research of polymer gel systems due to its unique analysis advantages.This paper is intent to review these works systematically.For in-situ cross-linked polymer gel systems,NMR can be used to characterize the chemical structure changes of the polymer,the cross-linker,and the auxiliary agent in the formulation of the polymer gel systems.Moreover,the gelation time and the gel strength of the in-situ cross-linked polymer gel systems can also be measured by NMR.For pre-formed polymer gels,NMR can be employed to detect the chemical structure of the designed products.Last,the NMR method can evaluate the plugging,water control,and oil improvement performance of the polymer gels in porous media without using dopants.This review can help readers build a more systematic understanding of the application of NMR technology in polymer gel systems for IOR and help re searchers to more deeply study the performance of polymer gel systems.
基金supported by the Research Foundation of China University of Petroleum-Beijing at Karamay(No.XQZX20200010)the Natural Science Foundation of Xinjiang Uygur Autonomous Region(No.2019D01B57)+2 种基金the Tianshan Talent Project(No.2019Q025)the Sichuan Province Regional Innovation Cooperation Project(No.2020YFQ0036)the CNPC Strategic Cooperation Science and Technology Project(ZLZX2020-01-04-04)
文摘Micro-scale and nano-scale dispersed gel particles(DPG)are capable of deep migration in oil reservoirs due to their deformability,viscoelasticity,and suitable particle size.Therefore,it has been widely studied and applied in reservoir conformance control in recent years.However,for highly permeable channels,their plugging performance is still limited.In addition,conventional in situ cross-linked polymer gels(ISCPGs)have fast gelation time under extremely high-temperature conditions,which often causes problems such as difficulty in pumping.Therefore,a re-cross linkable dispersed particle gel(RDPG)system applied for conformance control in highly permeable channels of extremely high-temperature petroleum reservoirs was investigated.The particle size distribution,gelation time,gel strength,injection performance,and perfo rmance strength in po rous media were investigated using a laser particle size meter,the Sydansk bottle test method,rheometer,and core displacement experiments,respectively.Results show that the RDPG suspension can be stable for more than 6 months at room temperature with storage modulus G’much lower than 10 Pa.It can pass through the pore throat by elastic deformation effect and does not cause strong blockage.Moreover,it can undergo re-crosslinking reaction at 150℃to form a strong bulk gel.The gel strength G’of re-crosslinked RDPG can be as high as 69.3 Pa,which meets the strength requirement of conformance control.The RDPG suspension has the properties of easy injection,and it also has strong plugging,and high-temperature resistance after re-crosslinked in the core,which can be a very promising material for conformance improvement in extremely high-temperature reservoirs.
基金Supported by the National Science and Technology Major Project(2017ZX05009-005-003)National Natural Science Foundation of China Funded General Project(52174045)+1 种基金Chinese Academy of Engineering Strategic Consulting Project(2018-XZ-09)China Nation al Petroleum Cor-poration-China University of Petroleum(Beijing)Strategic Cooperation Science and Technology Project(ZLZX2020-01)。
文摘Microscopic computed tomography(Micro-CT)is used to visualize microscopic flow in sandstone core samples during emulsion flooding.The images obtained during the experiment are processed quantitatively with a series of methods to evaluate the occurrence characteristics and oil recovery enhancement mechanisms of emulsion.(1)The emulsion is distributed in the cores in spherical shape,and its sphericity is significantly different from that of the remaining oil.Sphericity can be taken as a characteristic parameter to identify emulsion.(2)The emulsion with specific size prefers to stay in pores with matching sizes;when the emulsion volume is smaller than the product of the lower limit of pore occupancy and the corresponding pore vol-ume,it will not be able to effectively trap in the pore to achieve conformance control.In the process of emulsion displacement designing,we need to design emulsion with suitable particle size according to the pore distribution of the reservoir.(3)Mobi-lization ratio of the pores can be increased from 23.1%to 59.3%by emulsion flooding after subsequent water flooding,and the average oil displacement efficiency at the pore-scale can be increased from 22.9%to 75.8%under the test conditions;(4)After emulsion flooding,the clustered remaining oil and the oil phase in the trapped emulsion are the main targets for further EOR.
文摘Globally, traditional power systems are rapidly transforming towards the adoption of smart grid platforms. Substations which are at the center of the electric power transformation from the power plant are changing to IEC 61850 based digital substations. Therefore, within substation, there is a growing demand for the IEC 61850 based Intelligent Electronic Devices (IEDs). The operation of multiple manufacturers of IEDs in a single digital substation network increases the need for IEC 61850 communications specification conformance diagnosis to ensure interoperability for efficient data exchange between IEDs. The IEC 61850-10 presents test items for diagnosing communication specification conformance. There are many test tools available in the market today to test the compliance of the IEC 61850 communications specifications to the IED. In this paper, we propose a model-based diagnostic method for IED communication conformance testing. The proposed model-based software therefore uses the “drag and drop” technique to select the various IEC 61850 communication services (objects) required to design the test case in a user friendly Graphical User Interface (GUI). This makes the service conformance testing more flexible for test engineers and system integrators especially in situations that require test case modifications. Also, the proposed software tool makes it easy to understand the various IEC 61850 services using the friendly GUI.
文摘This paper describes the ISUP (ISDN User Part of CCSS7) conformance testing theory and method according to CCITT and China national standards, and presents a successful ISUP protocol conformance testing system in detail.
文摘In this paper, a conformance test platform is built for intelligent electronic devices (IEDs) from different manufacturers based on IEC 61850 communication protocol. A conformance test of time delay of message transmission between two IEDs, made by the same or different manufacturers, is performed. The conformance test platform, as well as the test results provide a helpful reference for IEC 61850 implementation.
文摘19 November 2013,Shenzhen-ZTE Corporation has announced that ZTE＇s ZSmart BSS/OSS V8 has successfully achieved TM Forum＇s Frameworx 12.0 Conformance Certification.TM Forum＇s Frameworx Conformance Certification is an independent verification of how a solution＇s business processes and information models align with the industry standards found in Frameworx,including the Business Process Framework（eTOM）and Information Framework（SID）.
基金the National Natural Science Foundation of China (No. 60572082)
文摘The session initiation protocol (SIP) is a signaling protocol for Internet telephony, multimedia conferencing, presence, event notification, and instant messaging. With the gaining popularity, more and more SIP implementations have been developed and deployed. How to guarantee the conformance of those SIP implementations is the key point of interconnection and interoperation among them. This paper proposes the test method and architecture for the SIP protocol based on the IPv6 tester system. Tree and tabular combined notation (TTCN-2) is adopted to describe the test suite. With an enhanced reference implementation, the data-processing ability to the original test system has been greatly improved. In the following test practices, some errors have been found in the SIP entities under test. It is proved that the proposed test method and architecture are effective to verify the conformance of the SIP entities, and the result of the conformance test may provide helpful reference to the development of SIP products.
文摘We present a method of generating test cases from the software specifications which are modeled by nondeterministic finite state machines. It is applicable to both nondeterministic and deterministic finite state machines. When applied to deterministic machines, this method yields usually smaller test suites with full fault coverage than the existing methods that also assure full fault coverage. In particular, the proposed mehod can be used to test the control portion of software specified in the formalspecification languages SDL or ESTELLE.
基金supported by the National Natural Sci-ence Foundation of China(Grant Nos.U1636208,NO 61862008).
文摘As cloud computing technology turning to mature,cloud services have become a trust-based service.Users'distrust of the security and performance of cloud services will hinder the rapid deployment and development of cloud services.So cloud service providers(CSPs)urgently need a way to prove that the infrastructure and the behavior of cloud services they provided can be trusted.The challenge here is how to construct a novel framework that can effective verify the security conformance of cloud services,which focuses on fine-grained descriptions of cloud service behavior and security service level aggreements(SLAs).In this paper,we propose a novel approach to verify cloud service security conformance,which reduces the description gap between the CSP and users through modeling cloud service behavior and security SLA,these models enable a systematic integration of security constraints and service behavior into cloud while using UPPAAL to check the performance and security conformance.The proposed approach is validated through case study and experiments with real cloud service based on Open-Stack,which illustrates CloudSec approach effectiveness and can be applied on realistic cloud scenario.
基金This research work was supported by Universiti Teknologi PETRONAS,Institute of Hydrocarbon Recovery UTP and Centre of Research Enhanced Oil Recovery(COREOR).The authors would also like to acknowledge the support from YUTP-Fundamental Research Grant(Cost centre:015LC0-218).
文摘Conformance control or water shut-off is a technique used to improve oil recovery.During conformance control,polymers block high permeability water areas and redistribute water drive toward unswept oil zones.In this study,co-polymers(denoted ATP-PGV/AM-co-AMPS)were synthesized using acrylamide(AM)and 2-acrylamide-2-methylpropane sulfonic acid(AMPS)as the monomers,polyethylene glycol(PEG)-200 and methylenebisacrylamide(MBA)as the crosslinkers,attapulgite(ATP)and bentonite(PGV)as the clay types,and ammonium persulfate(APS)as the initiator,in addition to paraffin oil and surfactants.Samples were synthesized using inverse emulsion polymerization with different concentrations of monomers,crosslinkers,and clays,and they were characterized using Fourier-transform infrared(FTIR)spectroscopy and scanning electron microscopy(SEM)with energy dispersive X-ray spectroscopy(EDX).FTIR spectra of the samples confirmed the existence of sulfonate and hydroxyl groups,which are important for polymer swelling.SEM-EDX images indicated that the morphology and elemental composition were different before and after swelling,confirming the occurrence of swelling.Moreover,samples were placed in sodium chloride solution(20,000 ppm)for 7 days to evaluate swelling at both room temperature and 90°C.Thermogravimetric analysis(TGA)and differential scanning calorimetry(DSC)were used to determine the thermal characteristics of the microparticles.Finally,rheological measurements were used to assess the deformation and rheological behavior of the hydrogels.The results showed that after 1 day,good swelling without loss of mechanical strength was achieved with the composite synthesized using 10%AM,15%AMPS,6%PGV,and 10%ATP.
文摘Exchanging simulation models is currently of utmost importance.To improve interoperability between suppliers and original equipment manufacturers(OEMs),the functional mock-up interface(FMI)is exchanged in a standard format called functional mock-up unit(FMU).Since its first release,many simulation tools took the initiative to support FMI.However,since then,there have been many complaints stating that exchanging models via FMI does not work as stable as expected.The reason usually turned out to be the implementation of tool vendors that sometimes fail to comply with the standard fully.This paper introduces a methodology for testing FMI compliance of importing simulation tools using a set of reference FMUs.The standard defines the implementation of FMI functions calling sequence in a state machine.Therefore,conformance testing(also called fault detection)from automata theory is utilized to produce reference FMUs based on the FMI state-machine.
