To master changes in rock mechanical properties and the impact of high temperature on rock-breaking efficiency,the rock mechanical properties of granite,limestone,and sandstone under different temperatures and single-...To master changes in rock mechanical properties and the impact of high temperature on rock-breaking efficiency,the rock mechanical properties of granite,limestone,and sandstone under different temperatures and single-tooth static-pressure experiments were studied.The results show that the compressive strength,shear strength,internal friction angle,and elastic modulus of granite and limestone initially increased and then decreased as the temperature rose.The experimental temperatures were 25℃,100℃,200℃,300℃,400℃,and 500℃.The mechanical properties of granite reached the maximum at 200℃,while those of limestone reached the maximum at 100℃.The compressive strength,shear strength,and internal friction angle of sandstone gradually diminished,while the elastic modulus gradually increased at the abovementioned five temperature points.Among the samples of granite,limestone,and sandstone,the crushing-specific work of conical teeth,wedge teeth,and scoop teeth was smallest when the temperature was 300℃.Compared to the normal temperature,the load of conical teeth,wedge teeth,and scoop teeth was reduced by 32.1%,28.4%,and 22.9%,respectively,when they were pressed into sandstone.At the same temperature,the conical tooth had the highest rock-breaking efficiency,followed by the wedge tooth;the scoop tooth had the lowest efficiency.Conical teeth can be used to select the tooth shapes of bits to improve drilling efficiency.Optimizing the tooth profile and conducting research on rock-breaking efficiency under different temperatures and rocks have an important role in bit design and can greatly improve drilling efficiency.展开更多
In ultra-deep and large well sections,high collapse stresses and diminished annular return velocity present significant challenges to wellbore cleaning.With increasing depth,rising temperature and pressure constrain t...In ultra-deep and large well sections,high collapse stresses and diminished annular return velocity present significant challenges to wellbore cleaning.With increasing depth,rising temperature and pressure constrain the regulation of displacement and drilling fluid rheology,impairing the fluid’s capacity to transport cuttings effectively.A precise understanding of cuttings settlement behavior and terminal velocity is therefore essential for optimizing their removal.This study accounts for variations in wellbore temperature and pressure,incorporates non-spherical cuttings and wellbore diameter parameters,and develops accordingly a simplified model to predict terminal settlement velocity.Thecuttings carrying ratio is introduced as a metric for evaluatingwellbore cleanliness.Findings reveal that temperature and pressure fluctuations can alter terminal velocity by up to 3.4%.Cuttings shape plays a crucial role,with block-shaped cuttings requiring higher annular return velocity than flake-shaped ones at the same carrying ratio.As wellbore size increases,the minimum required carrying flow rate rises nonlinearly,though the rate of increase gradually declines.For a Φ444.5mmwellbore,a carrying ratio of at least 0.6 is recommended.Terminal velocity decreases with increasing consistency coefficient,particularly in high-viscosity regimes.The proposed carrying ratio offers a more accurate and practical assessment of wellbore cleanliness.展开更多
Gastric cancer(GC)is the third most common cause of cancer death globally and a large portion of patients are diagnosed at advanced stages with cancer invasion and metastasis1,2.However,the mechanisms underlying the i...Gastric cancer(GC)is the third most common cause of cancer death globally and a large portion of patients are diagnosed at advanced stages with cancer invasion and metastasis1,2.However,the mechanisms underlying the invasion and metastasis of GC remain to be delineated.ZYX plays critical roles in cell mobility via cytoskeleton regulation in various cell types.3 In this study,we further reported that ZYX promoted migration,invasion,and metastasis of GC cells.Mechanistically,ZYX promoted WNK1 activation and SNAl1 up-regulation,inducing epithelial-mesenchymal transition(EMT)to enhance the mobility of GC cells.Inhibition of WNK1 impaired the mobility of GC cells.Therefore,ZYX/WNK1 could be potential therapeutic targets for GC treatment.展开更多
基金supported by the CNPC Chuanqing Drilling Engineering Co.,Ltd.,China(Grant Nos.CQ2024B-1-Z4-3 and CQ2024B-1-Z3-3)the CNPC Technology Project,China(Grant No.2024ZG39)the CNPC Technical Service Science Research and Technology Development Project,China(Grant No.2024T-001-002).
文摘To master changes in rock mechanical properties and the impact of high temperature on rock-breaking efficiency,the rock mechanical properties of granite,limestone,and sandstone under different temperatures and single-tooth static-pressure experiments were studied.The results show that the compressive strength,shear strength,internal friction angle,and elastic modulus of granite and limestone initially increased and then decreased as the temperature rose.The experimental temperatures were 25℃,100℃,200℃,300℃,400℃,and 500℃.The mechanical properties of granite reached the maximum at 200℃,while those of limestone reached the maximum at 100℃.The compressive strength,shear strength,and internal friction angle of sandstone gradually diminished,while the elastic modulus gradually increased at the abovementioned five temperature points.Among the samples of granite,limestone,and sandstone,the crushing-specific work of conical teeth,wedge teeth,and scoop teeth was smallest when the temperature was 300℃.Compared to the normal temperature,the load of conical teeth,wedge teeth,and scoop teeth was reduced by 32.1%,28.4%,and 22.9%,respectively,when they were pressed into sandstone.At the same temperature,the conical tooth had the highest rock-breaking efficiency,followed by the wedge tooth;the scoop tooth had the lowest efficiency.Conical teeth can be used to select the tooth shapes of bits to improve drilling efficiency.Optimizing the tooth profile and conducting research on rock-breaking efficiency under different temperatures and rocks have an important role in bit design and can greatly improve drilling efficiency.
基金partly supported by the National Natural Science Foundation of China(52304045)the Open Fund(PLN2023-40)of the National Key Laboratory of Oil and Gas Reservoir Geology and Exploitation(Southwest Petroleum University)the Open Fund(2024-KFKT-08)of China National Petroleum Corporation Science and Technology Research Institute.
文摘In ultra-deep and large well sections,high collapse stresses and diminished annular return velocity present significant challenges to wellbore cleaning.With increasing depth,rising temperature and pressure constrain the regulation of displacement and drilling fluid rheology,impairing the fluid’s capacity to transport cuttings effectively.A precise understanding of cuttings settlement behavior and terminal velocity is therefore essential for optimizing their removal.This study accounts for variations in wellbore temperature and pressure,incorporates non-spherical cuttings and wellbore diameter parameters,and develops accordingly a simplified model to predict terminal settlement velocity.Thecuttings carrying ratio is introduced as a metric for evaluatingwellbore cleanliness.Findings reveal that temperature and pressure fluctuations can alter terminal velocity by up to 3.4%.Cuttings shape plays a crucial role,with block-shaped cuttings requiring higher annular return velocity than flake-shaped ones at the same carrying ratio.As wellbore size increases,the minimum required carrying flow rate rises nonlinearly,though the rate of increase gradually declines.For a Φ444.5mmwellbore,a carrying ratio of at least 0.6 is recommended.Terminal velocity decreases with increasing consistency coefficient,particularly in high-viscosity regimes.The proposed carrying ratio offers a more accurate and practical assessment of wellbore cleanliness.
基金supported by the Chongqing Academician Program(No.cstc2019yszx-jcyjx0008 to Y.W.)The Subject of Health Commission of Hubei Province,China(No.WJ2021M222 to X.-M.W.).
文摘Gastric cancer(GC)is the third most common cause of cancer death globally and a large portion of patients are diagnosed at advanced stages with cancer invasion and metastasis1,2.However,the mechanisms underlying the invasion and metastasis of GC remain to be delineated.ZYX plays critical roles in cell mobility via cytoskeleton regulation in various cell types.3 In this study,we further reported that ZYX promoted migration,invasion,and metastasis of GC cells.Mechanistically,ZYX promoted WNK1 activation and SNAl1 up-regulation,inducing epithelial-mesenchymal transition(EMT)to enhance the mobility of GC cells.Inhibition of WNK1 impaired the mobility of GC cells.Therefore,ZYX/WNK1 could be potential therapeutic targets for GC treatment.
