Research and application of thermal insulation effect of natural gas hydrate freezing corer based on the wireline-coring principle

Natural gas hydrate(NGH)holds great promise as a source of clean energy.It is critical for acquiring the largest possible in situ NGH core for NGH eigen features and resource assessment.However,the existing NGH coring technology has limitations,such as temperature increments,limited coring diameters,low coring rates,and complex coring structures.Therefore,this study designs and proposes an NGH freezing coring(NGHFC)method and verifies the freezing and coring capacities of the NGHFC method in laboratories and experimental wells.Results suggest that NGHFC shows good freezing and heat-retention properties.A freezing core heat transfer model is developed.According to the actual air temperature and operating time,the optimum initial temperature of the cold source can be determined using this model.The average coring rate of NGHFC can reach 77.86%.The research results will provide a new idea of coring gas hydrates.

Development of an ultra-high-pressure rotary combined dynamic seal and experimental study on its sealing performance in deep energy mining conditions

With the continuous development of deep oil and gas,minerals,geothermal resources,and other resources,there are increasingly more stringent requirements for equipment.In particular,the ultra-highpressure dynamic seals of deep mining device need to be developed.Therefore,considering the use of dynamic seals in unique deep mining environments,an ultra-high-pressure rotating combined dynamic seal was designed and developed and its sealing performance was experimentally measured and analyzed.The results show that the experimental device can operate stably under a pressure of up to150 MPa and a rotating speed of 76 r/min,and can also operate normally under a rotating speed of up to 140 r/min and a sealing pressure of 120 MPa.During the operation of the ultra-high-pressure rotating combined dynamic seal,the sealing ring does not show obvious damage,which vouches for its sealing performance.No leakage of flow and pressure was detected in the all seal structures within the sealing pressure range of 0-150 MPa.Therefore,the dynamic sealing performance of the device is intact under ultra-high-pressure conditions and can be applied in deep mining environments at a certain depth.The research and development of this device can aid future deep energy exploration and exploitation.

Correlation of serum CNP and IGF-Ⅱ contents with brain injury and inflammatory response in patients with craniocerebral trauma

Objective:To study the correlation of serum C-type natriuretic peptide (CNP) and insulin-like growth factor-Ⅱ (IGF-Ⅱ) contents with brain injury and inflammatory response in patients with craniocerebral trauma.Methods: Patients with craniocerebral trauma who were treated in the First Affiliated Hospital of Xi'an Jiaotong University between March 2015 and July 2017 were included in the case group of the study, and the healthy volunteers who received physical examination during the same period were included in the control group. The contents of CNP, IGF-Ⅱ, nerve markers and pro-inflammatory cytokines in serum as well as the expression of inflammatory signaling molecules in peripheral blood were measured.Results: CNP and IGF-Ⅱ contents in serum of case group were significantly lower than those of control group whereas UCH-L1, GFAP, S100B, Tau, MIP-1α, IL-1β, IL-6, IL-8 and TNF-α contents in serum as well as JAK2, STAT3, MEK and ERK1/2 mRNA expression in peripheral blood were significantly higher than those of control group;CNP and IGF-Ⅱ contents in serum of case group were negatively correlated with UCH-L1, GFAP, S100B, Tau, MIP-1α, IL-1β, IL-6, IL-8 and TNF-α contents in serum as well as JAK2, STAT3, MEK and ERK1/2 mRNA expression in peripheral blood.Conclusion: The decrease of serum CNP and IGF-Ⅱ in patients with craniocerebral trauma is closely related to the aggravation of brain injury and the over-activation of inflammatory response.