BACKGROUND Colorectal surgeons are well aware that performing surgery for rectal cancer becomes more challenging in obese patients with narrow and deep pelvic cavities.Therefore,it is essential for colorectal surgeons...BACKGROUND Colorectal surgeons are well aware that performing surgery for rectal cancer becomes more challenging in obese patients with narrow and deep pelvic cavities.Therefore,it is essential for colorectal surgeons to have a comprehensive understanding of pelvic structure prior to surgery and anticipate potential surgical difficulties.AIM To evaluate predictive parameters for technical challenges encountered during laparoscopic radical sphincter-preserving surgery for rectal cancer.METHODS We retrospectively gathered data from 162 consecutive patients who underwent laparoscopic radical sphincterpreserving surgery for rectal cancer.Three-dimensional reconstruction of pelvic bone and soft tissue parameters was conducted using computed tomography(CT)scans.Operative difficulty was categorized as either high or low,and multivariate logistic regression analysis was employed to identify predictors of operative difficulty,ultimately creating a nomogram.RESULTS Out of 162 patients,21(13.0%)were classified in the high surgical difficulty group,while 141(87.0%)were in the low surgical difficulty group.Multivariate logistic regression analysis showed that the surgical approach using laparoscopic intersphincteric dissection,intraoperative preventive ostomy,and the sacrococcygeal distance were independent risk factors for highly difficult laparoscopic radical sphincter-sparing surgery for rectal cancer(P<0.05).Conversely,the anterior-posterior diameter of pelvic inlet/sacrococcygeal distance was identified as a protective factor(P<0.05).A nomogram was subsequently constructed,demonstrating good predictive accuracy(C-index=0.834).CONCLUSION The surgical approach,intraoperative preventive ostomy,the sacrococcygeal distance,and the anterior-posterior diameter of pelvic inlet/sacrococcygeal distance could help to predict the difficulty of laparoscopic radical sphincter-preserving surgery.展开更多
In the Sichuan Basin,carbonate reservoirs are characterized by deep burial depth and strong heterogeneity,so it is difficult to conduct structure steering,pore space reservoir tracking and trajectory control in the pr...In the Sichuan Basin,carbonate reservoirs are characterized by deep burial depth and strong heterogeneity,so it is difficult to conduct structure steering,pore space reservoir tracking and trajectory control in the process of geosteering logging while drilling.In this paper,a series of corresponding techniques for structure,reservoir and formation tracking were proposed after analysis was conducted on multiple series of carbonate strata in terms of their geologic and logging response characteristics.And investigation was performed on the adaptabilities of the following logging technologies to geosteering while drilling,including gamma ray imaging while drilling,resistivity imaging while drilling,density imaging while drilling,gamma ray logging while drilling,resistivity logging while drilling,neutron logging while drilling and density logging while drilling.After while drilling information was thoroughly analyzed,the logging suites for four common types of complicated reservoirs(thin layered reservoirs,thick massive reservoirs,denuded karst reservoirs and shale gas reservoirs)were optimized,and five logging combinations suitable for different formations and reservoirs were proposed,including gamma ray logging t porosity t resistivity imaging,gamma ray logging t resistivity imaging,gamma ray logging t porosity t resistivity logging,gamma ray imaging t resistivity logging,and gamma ray logging.Field application indicates that it is of great reference and application value to use this method for the first time to summarize logging while drilling combinations for different types of carbonate reservoirs.展开更多
In the society with increasing development, because of the higher and higher economic level of people, more people pursue higher standard of life and the construction industry is also rising and developing, so all ent...In the society with increasing development, because of the higher and higher economic level of people, more people pursue higher standard of life and the construction industry is also rising and developing, so all enterprises are actively competing. The construction industry is related to people's living, so developers in the construction of all aspects of the security must be strictly controlled and the quality of construction is also the focus of attention among all builders. The materials in construction should be strictly checked. Now most of the construction industry adopts reinforced concrete structure. Therefore, reinforced concrete should be strictly checked when selecting, and its quality directly affects the quality of the whole construction project. It will have a great impact on the construction period and its cost of the whole project, not only the submission of the construction period, but also the safety of people. Therefore, in order to avoid such dangerous situation, the selection of concrete should be strictly checked in order to ensure the quality and to strengthen the optimization of the pouring level of concrete. Thus, the construction quality and economic value can be improved. Based on this, this paper studies the technical difficulties of concrete pouring construction in construction engineering for reference.展开更多
By reviewing the development history of stimulation techniques for deep/ultra-deep oil and gas reservoirs,the new progress in this field in China and abroad has been summed up,including deeper understanding on formati...By reviewing the development history of stimulation techniques for deep/ultra-deep oil and gas reservoirs,the new progress in this field in China and abroad has been summed up,including deeper understanding on formation mechanisms of fracture network in deep/ultra-deep oil and gas reservoir,performance improvement of fracturing fluid materials,fine stratification of ultra-deep vertical wells,and mature staged multi-cluster fracturing technique for ultra-deep and highly deviated wells/horizontal wells.In light of the exploration and development trend of ultra-deep oil and gas reservoirs in China,the requirements and technical difficulties in ultra-deep oil and gas reservoir stimulation are discussed:(1)The research and application of integrated geological engineering technology is difficult.(2)The requirements on fracturing materials for stimulation are high.(3)It is difficult to further improve the production in vertical profile of the ultra-deep and hugely thick reservoirs.(4)The requirements on tools and supporting high-pressure equipment on the ground for stimulation are high.(5)It is difficult to achieve efficient stimulation of ultra-deep,high-temperature and high-pressure wells.(6)It is difficult to monitor directly the reservoir stimulation and evaluate the stimulation effect accurately after stimulation.In line with the complex geological characteristics of ultra-deep oil and gas reservoirs in China,seven technical development directions are proposed:(1)To establish systematic new techniques for basic research and evaluation experiments;(2)to strengthen geological research and improve the operational mechanism of integrating geological research and engineering operation;(3)to develop high-efficiency fracturing materials for ultra-deep reservoirs;(4)to research separated layer fracturing technology for ultra-deep and hugely thick reservoirs;(5)to explore fracture-control stimulation technology for ultra-deep horizontal well;(6)to develop direct monitoring technology for hydraulic fractures in ultra-deep oil and gas reservoirs;(7)to develop downhole fracturing tools with high temperature and high pressure tolerance and supporting wellhead equipment able to withstand high pressure.展开更多
According to the investigation and analysis of the production situation of horizontal wells in major oilfields at home and abroad, there are five types of accidents in horizontal wells, namely, blockage caused by fall...According to the investigation and analysis of the production situation of horizontal wells in major oilfields at home and abroad, there are five types of accidents in horizontal wells, namely, blockage caused by falling objects, blockage caused by string breaking, blockage caused by downhole tools, blockage caused by casing damage and other types of failures. Influenced by factors such as large angle of inclination, long horizontal section and large curvature of borehole, there are six technical difficulties in the process of horizontal well overhaul, such as difficulty in fishing, difficulty in running and pulling out large-diameter tools, serious weight loss on bit, easy wear of lead mold, high friction between string and casing, and difficulty in sand production. Therefore, the technical countermeasures are studied, including the fishing technology of horizontal well, drilling and grinding technology of horizontal well, continuous sand washing technology of horizontal well, etc. The composition, technical principle and construction technology of key pipe strings are analyzed and studied. Taking L Oilfield as an example, the application effect of horizontal well overhaul technology is analyzed. The obtained results and knowledge can provide reference experience for peers.展开更多
基金Institutional review board statement:The study was reviewed and approved by the Wenzhou Central Hospital Institutional Review Board(Approval No.K2018-01-003).
文摘BACKGROUND Colorectal surgeons are well aware that performing surgery for rectal cancer becomes more challenging in obese patients with narrow and deep pelvic cavities.Therefore,it is essential for colorectal surgeons to have a comprehensive understanding of pelvic structure prior to surgery and anticipate potential surgical difficulties.AIM To evaluate predictive parameters for technical challenges encountered during laparoscopic radical sphincter-preserving surgery for rectal cancer.METHODS We retrospectively gathered data from 162 consecutive patients who underwent laparoscopic radical sphincterpreserving surgery for rectal cancer.Three-dimensional reconstruction of pelvic bone and soft tissue parameters was conducted using computed tomography(CT)scans.Operative difficulty was categorized as either high or low,and multivariate logistic regression analysis was employed to identify predictors of operative difficulty,ultimately creating a nomogram.RESULTS Out of 162 patients,21(13.0%)were classified in the high surgical difficulty group,while 141(87.0%)were in the low surgical difficulty group.Multivariate logistic regression analysis showed that the surgical approach using laparoscopic intersphincteric dissection,intraoperative preventive ostomy,and the sacrococcygeal distance were independent risk factors for highly difficult laparoscopic radical sphincter-sparing surgery for rectal cancer(P<0.05).Conversely,the anterior-posterior diameter of pelvic inlet/sacrococcygeal distance was identified as a protective factor(P<0.05).A nomogram was subsequently constructed,demonstrating good predictive accuracy(C-index=0.834).CONCLUSION The surgical approach,intraoperative preventive ostomy,the sacrococcygeal distance,and the anterior-posterior diameter of pelvic inlet/sacrococcygeal distance could help to predict the difficulty of laparoscopic radical sphincter-preserving surgery.
基金Supported by“Well logging-based shale gas evaluation”,a sub-project of National Science and Technology Major Project(No.2011ZX05018-003)“Interpretation and supporting system development for electromagnetic wave imaging and well logging while drilling”,a China National Petroleum Corporation Science and Technology Major Project(No.2013E-3809).
文摘In the Sichuan Basin,carbonate reservoirs are characterized by deep burial depth and strong heterogeneity,so it is difficult to conduct structure steering,pore space reservoir tracking and trajectory control in the process of geosteering logging while drilling.In this paper,a series of corresponding techniques for structure,reservoir and formation tracking were proposed after analysis was conducted on multiple series of carbonate strata in terms of their geologic and logging response characteristics.And investigation was performed on the adaptabilities of the following logging technologies to geosteering while drilling,including gamma ray imaging while drilling,resistivity imaging while drilling,density imaging while drilling,gamma ray logging while drilling,resistivity logging while drilling,neutron logging while drilling and density logging while drilling.After while drilling information was thoroughly analyzed,the logging suites for four common types of complicated reservoirs(thin layered reservoirs,thick massive reservoirs,denuded karst reservoirs and shale gas reservoirs)were optimized,and five logging combinations suitable for different formations and reservoirs were proposed,including gamma ray logging t porosity t resistivity imaging,gamma ray logging t resistivity imaging,gamma ray logging t porosity t resistivity logging,gamma ray imaging t resistivity logging,and gamma ray logging.Field application indicates that it is of great reference and application value to use this method for the first time to summarize logging while drilling combinations for different types of carbonate reservoirs.
文摘In the society with increasing development, because of the higher and higher economic level of people, more people pursue higher standard of life and the construction industry is also rising and developing, so all enterprises are actively competing. The construction industry is related to people's living, so developers in the construction of all aspects of the security must be strictly controlled and the quality of construction is also the focus of attention among all builders. The materials in construction should be strictly checked. Now most of the construction industry adopts reinforced concrete structure. Therefore, reinforced concrete should be strictly checked when selecting, and its quality directly affects the quality of the whole construction project. It will have a great impact on the construction period and its cost of the whole project, not only the submission of the construction period, but also the safety of people. Therefore, in order to avoid such dangerous situation, the selection of concrete should be strictly checked in order to ensure the quality and to strengthen the optimization of the pouring level of concrete. Thus, the construction quality and economic value can be improved. Based on this, this paper studies the technical difficulties of concrete pouring construction in construction engineering for reference.
基金Supported by the China National Science and Technology Major Project(2016ZX05023)Petro China Science and Technology Major Project(2018E-1809)。
文摘By reviewing the development history of stimulation techniques for deep/ultra-deep oil and gas reservoirs,the new progress in this field in China and abroad has been summed up,including deeper understanding on formation mechanisms of fracture network in deep/ultra-deep oil and gas reservoir,performance improvement of fracturing fluid materials,fine stratification of ultra-deep vertical wells,and mature staged multi-cluster fracturing technique for ultra-deep and highly deviated wells/horizontal wells.In light of the exploration and development trend of ultra-deep oil and gas reservoirs in China,the requirements and technical difficulties in ultra-deep oil and gas reservoir stimulation are discussed:(1)The research and application of integrated geological engineering technology is difficult.(2)The requirements on fracturing materials for stimulation are high.(3)It is difficult to further improve the production in vertical profile of the ultra-deep and hugely thick reservoirs.(4)The requirements on tools and supporting high-pressure equipment on the ground for stimulation are high.(5)It is difficult to achieve efficient stimulation of ultra-deep,high-temperature and high-pressure wells.(6)It is difficult to monitor directly the reservoir stimulation and evaluate the stimulation effect accurately after stimulation.In line with the complex geological characteristics of ultra-deep oil and gas reservoirs in China,seven technical development directions are proposed:(1)To establish systematic new techniques for basic research and evaluation experiments;(2)to strengthen geological research and improve the operational mechanism of integrating geological research and engineering operation;(3)to develop high-efficiency fracturing materials for ultra-deep reservoirs;(4)to research separated layer fracturing technology for ultra-deep and hugely thick reservoirs;(5)to explore fracture-control stimulation technology for ultra-deep horizontal well;(6)to develop direct monitoring technology for hydraulic fractures in ultra-deep oil and gas reservoirs;(7)to develop downhole fracturing tools with high temperature and high pressure tolerance and supporting wellhead equipment able to withstand high pressure.
文摘According to the investigation and analysis of the production situation of horizontal wells in major oilfields at home and abroad, there are five types of accidents in horizontal wells, namely, blockage caused by falling objects, blockage caused by string breaking, blockage caused by downhole tools, blockage caused by casing damage and other types of failures. Influenced by factors such as large angle of inclination, long horizontal section and large curvature of borehole, there are six technical difficulties in the process of horizontal well overhaul, such as difficulty in fishing, difficulty in running and pulling out large-diameter tools, serious weight loss on bit, easy wear of lead mold, high friction between string and casing, and difficulty in sand production. Therefore, the technical countermeasures are studied, including the fishing technology of horizontal well, drilling and grinding technology of horizontal well, continuous sand washing technology of horizontal well, etc. The composition, technical principle and construction technology of key pipe strings are analyzed and studied. Taking L Oilfield as an example, the application effect of horizontal well overhaul technology is analyzed. The obtained results and knowledge can provide reference experience for peers.
