In view of complex geological characteristics and alternating loading conditions associated with cyclic large amount of gas injection and withdrawal in underground gas storage(UGS) of China, a series of key gas storag...In view of complex geological characteristics and alternating loading conditions associated with cyclic large amount of gas injection and withdrawal in underground gas storage(UGS) of China, a series of key gas storage construction technologies were established, mainly including UGS site selection and evaluation, key index design, well drilling and completion, surface engineering and operational risk warning and assessment, etc. The effect of field application was discussed and summarized. Firstly, trap dynamic sealing capacity evaluation technology for conversion of UGS from the fault depleted or partially depleted gas reservoirs. A key index design method mainly based on the effective gas storage capacity design for water flooded heterogeneous gas reservoirs was proposed. To effectively guide the engineering construction of UGS, the safe well drilling, high quality cementing and high pressure and large flow surface injection and production engineering optimization suitable for long-term alternate loading condition and ultra-deep and ultra-low temperature formation were developed. The core surface equipment like high pressure gas injection compressor can be manufactured by our own. Last, the full-system operational risk warning and assessment technology for UGS was set up. The above 5 key technologies have been utilized in site selection, development scheme design, engineering construction and annual operations of 6 UGS groups, e.g. the Hutubi UGS in Xinjiang. To date, designed main indexes are highly consistent with actural performance, the 6 UGS groups have the load capacity of over 7.5 billion cubic meters of working gas volume and all the storage facilities have been running efficiently and safely.展开更多
UGS(underground gas storage)construction in China has stepped into a new development stage after years of exploration.The eleven UGSs that have been put into production play an important role in domestic natural gas p...UGS(underground gas storage)construction in China has stepped into a new development stage after years of exploration.The eleven UGSs that have been put into production play an important role in domestic natural gas peak shaving safety and supply guarantee,with designed working gas volume of 180×10^(8) m^(3),but there are still various difficulties in UGS construction in China.Firstly,the increasing speed of working gas volume is slower than that of peak shaving demand volume.Secondly,the UGS building engineering is difficult in technologies and high in investment costs.Thirdly,safe operation is under high pressure and it is hard to identify and control risks.Fourthly,there are fewer candidate UGS sites in China and UGS building conditions are complicated.And fifthly,it is difficult for those UGSs to realize economic benefits only based on their own operation under the existing natural gas price systems.To sum up,the currently available UGS operation modes and building technologies in China are not sufficient to cope with the challenges resulted from markets and complex geologic conditions.Facing all these challenges,it is necessary not only to explore market driven operation modes,but also to strengthen technology tackling and carry out core technological research and development,including geologic evaluation,gas reservoir engineering,drilling and completion engineering,UGS injection and gas recovery engineering,surface auxiliary technologies and UGS integrity evaluation,so that UGS building efficiency can be increased greatly.展开更多
Distributed key value storage systems are among the most important types of distributed storage systems currently deployed in data centers. Nowadays, enterprise data centers are facing growing pressure in reducing the...Distributed key value storage systems are among the most important types of distributed storage systems currently deployed in data centers. Nowadays, enterprise data centers are facing growing pressure in reducing their power consumption. In this paper, we propose GreenCHT, a reliable power management scheme for consistent hashing based distributed key value storage systems. It consists of a multi-tier replication scheme, a reliable distributed log store, and a predictive power mode scheduler （PMS）. Instead of randomly placing replicas of each object on a number of nodes in the consistent hash ring, we arrange the replicas of objects on nonoverlapping tiers of nodes in the ring. This allows the system to fall in various power modes by powering down subsets of servers while not violating data availability. The predictive PMS predicts workloads and adapts to load fluctuation. It cooperates with the multi-tier replication strategy to provide power proportionality for the system. To ensure that the reliability of the system is maintained when replicas are powered down, we distribute the writes to standby replicas to active servers, which ensures failure tolerance of the system. GreenCHT is implemented based on Sheepdog, a distributed key value storage system that uses consistent hashing as an underlying distributed hash table. By replaying 12 typical real workload traces collected from Microsoft, the evaluation results show that GreenCHT can provide significant power savings while maintaining a desired performance. We observe that GreenCHT can reduce power consumption by up to 35%-61%.展开更多
Virtualization and distributed parallel architecture are typical cloud computing technologies. In the area of virtuatization technology, this article discusses physical resource pooling, resource pool management and u...Virtualization and distributed parallel architecture are typical cloud computing technologies. In the area of virtuatization technology, this article discusses physical resource pooling, resource pool management and use, cluster fault location and maintenance, resource pool grouping, and construction and application of heterogeneous virtualization platforms. In the area of distributed technology, distributed file system and KeyNalue storage engine are discussed. A solution is proposed for the host bottleneck problem, and a standard storage interface is proposed for the distributed file system. A directory-based storage scheme for Key/Value storage engine is also proposed.展开更多
1 Introduction The LSM-tree has become a preferred solution for the storage structure of key-value(KV)NoSQL systems due to its efficient write performance[1,2].Its ability to efficiently process large-scale data write...1 Introduction The LSM-tree has become a preferred solution for the storage structure of key-value(KV)NoSQL systems due to its efficient write performance[1,2].Its ability to efficiently process large-scale data write operations makes it show high performance in handling TP(Transactional Processing)tasks.The increasing volume of real-time data processing and complex analytics tasks in current applications has made it necessary for databases to support HTAP(Hybrid Transactional/Analytical Processing)workloads.展开更多
基金Supported by the CNPC Science and Technology Major Project(2015E-4002)
文摘In view of complex geological characteristics and alternating loading conditions associated with cyclic large amount of gas injection and withdrawal in underground gas storage(UGS) of China, a series of key gas storage construction technologies were established, mainly including UGS site selection and evaluation, key index design, well drilling and completion, surface engineering and operational risk warning and assessment, etc. The effect of field application was discussed and summarized. Firstly, trap dynamic sealing capacity evaluation technology for conversion of UGS from the fault depleted or partially depleted gas reservoirs. A key index design method mainly based on the effective gas storage capacity design for water flooded heterogeneous gas reservoirs was proposed. To effectively guide the engineering construction of UGS, the safe well drilling, high quality cementing and high pressure and large flow surface injection and production engineering optimization suitable for long-term alternate loading condition and ultra-deep and ultra-low temperature formation were developed. The core surface equipment like high pressure gas injection compressor can be manufactured by our own. Last, the full-system operational risk warning and assessment technology for UGS was set up. The above 5 key technologies have been utilized in site selection, development scheme design, engineering construction and annual operations of 6 UGS groups, e.g. the Hutubi UGS in Xinjiang. To date, designed main indexes are highly consistent with actural performance, the 6 UGS groups have the load capacity of over 7.5 billion cubic meters of working gas volume and all the storage facilities have been running efficiently and safely.
文摘UGS(underground gas storage)construction in China has stepped into a new development stage after years of exploration.The eleven UGSs that have been put into production play an important role in domestic natural gas peak shaving safety and supply guarantee,with designed working gas volume of 180×10^(8) m^(3),but there are still various difficulties in UGS construction in China.Firstly,the increasing speed of working gas volume is slower than that of peak shaving demand volume.Secondly,the UGS building engineering is difficult in technologies and high in investment costs.Thirdly,safe operation is under high pressure and it is hard to identify and control risks.Fourthly,there are fewer candidate UGS sites in China and UGS building conditions are complicated.And fifthly,it is difficult for those UGSs to realize economic benefits only based on their own operation under the existing natural gas price systems.To sum up,the currently available UGS operation modes and building technologies in China are not sufficient to cope with the challenges resulted from markets and complex geologic conditions.Facing all these challenges,it is necessary not only to explore market driven operation modes,but also to strengthen technology tackling and carry out core technological research and development,including geologic evaluation,gas reservoir engineering,drilling and completion engineering,UGS injection and gas recovery engineering,surface auxiliary technologies and UGS integrity evaluation,so that UGS building efficiency can be increased greatly.
文摘Distributed key value storage systems are among the most important types of distributed storage systems currently deployed in data centers. Nowadays, enterprise data centers are facing growing pressure in reducing their power consumption. In this paper, we propose GreenCHT, a reliable power management scheme for consistent hashing based distributed key value storage systems. It consists of a multi-tier replication scheme, a reliable distributed log store, and a predictive power mode scheduler （PMS）. Instead of randomly placing replicas of each object on a number of nodes in the consistent hash ring, we arrange the replicas of objects on nonoverlapping tiers of nodes in the ring. This allows the system to fall in various power modes by powering down subsets of servers while not violating data availability. The predictive PMS predicts workloads and adapts to load fluctuation. It cooperates with the multi-tier replication strategy to provide power proportionality for the system. To ensure that the reliability of the system is maintained when replicas are powered down, we distribute the writes to standby replicas to active servers, which ensures failure tolerance of the system. GreenCHT is implemented based on Sheepdog, a distributed key value storage system that uses consistent hashing as an underlying distributed hash table. By replaying 12 typical real workload traces collected from Microsoft, the evaluation results show that GreenCHT can provide significant power savings while maintaining a desired performance. We observe that GreenCHT can reduce power consumption by up to 35%-61%.
文摘Virtualization and distributed parallel architecture are typical cloud computing technologies. In the area of virtuatization technology, this article discusses physical resource pooling, resource pool management and use, cluster fault location and maintenance, resource pool grouping, and construction and application of heterogeneous virtualization platforms. In the area of distributed technology, distributed file system and KeyNalue storage engine are discussed. A solution is proposed for the host bottleneck problem, and a standard storage interface is proposed for the distributed file system. A directory-based storage scheme for Key/Value storage engine is also proposed.
基金supported by the Fundamental Research Funds for the National Natural Science Foundation of China under Grant No.62472077.
文摘1 Introduction The LSM-tree has become a preferred solution for the storage structure of key-value(KV)NoSQL systems due to its efficient write performance[1,2].Its ability to efficiently process large-scale data write operations makes it show high performance in handling TP(Transactional Processing)tasks.The increasing volume of real-time data processing and complex analytics tasks in current applications has made it necessary for databases to support HTAP(Hybrid Transactional/Analytical Processing)workloads.
