Influence of gas transport mechanisms on the productivity of multi-stage fractured horizontal wells in shale gas reservoirs

In order to investigate the influence on shale gas well productivity caused by gas transport in nanometer- size pores, a mathematical model of multi-stage fractured horizontal wells in shale gas reservoirs is built, which considers the influence of viscous flow, Knudsen diffusion, surface diffusion, and adsorption layer thickness. A dis- crete-fracture model is used to simplify the fracture mod- cling, and a finite element method is applied to solve the model. The numerical simulation results indicate that with a decrease in the intrinsic matrix permeability, Knudsen diffusion and surface diffusion contributions to production become large and cannot be ignored. The existence of an adsorption layer on the nanopore surfaces reduces the effective pore radius and the effective porosity, resulting in low production from fractured horizontal wells. With a decrease in the pore radius, considering the adsorption layer, the production reduction rate increases. When the pore radius is less than 10 nm, because of the combined impacts of Knudsen diffusion, surface diffusion, and adsorption layers, the production of multi-stage fractured horizontal wells increases with a decrease in the pore pressure. When the pore pressure is lower than 30 MPa, the rate of production increase becomes larger with a decrease in pore pressure.

Efficacy and Safety of Domestic Leuprorelin in Girls with Idiopathic Central Precocious Puberty： A Multicenter,Randomized, Parallel, Controlled Trial

Background：In central precocious puberty （CPP）,the pulse secretion and release ofgonadotropin-releasing hormone （GnRH） are increased due to early activation of the hypothalamic-pituitary-gonadal axis,resulting in developmental abnormalities with gonadal development and appearance of secondary sexual characteristics.The CPP without organic disease is known as idiopathic CPP （ICPP）.The objective of the study was to evaluate the clinical efficacy and safety of domestic leuprorelin （GnRH analog） in girls with ICPP.Methods：A total of 236 girls with ICPP diagnosed from April 2012 to January 2014 were selected and were randomized into two groups.One hundred fifty-seven girls in the test group were treated with domestic leuprorelin acetate,79 girls in the control group were treated with imported leuprorelin acetate.They all were treated and observed for 6 months.After 6-month treatment,the percentage of children with peak luteinizing hormone （LH） ≤3.3 U/L,the percentage of children with peak LH/peak follicle stimulating hormone （FSH） ratio 〈0.6,the improvements of secondary sexual characteristics,gonadal development and sex hormone levels,the change of growth rate of bone age （BA） and growth velocity,and drug adverse effects between two groups were compared.Results：After the treatment,the percentage of children with a suppressed LH response to GnRH,defined as a peak LH ≤3.3 U/L,at 6 months in test and control groups were 96.80% and 96.20%,respectively,and the percentage of children with peak LH/FSH ratio ≤0.6 at 6 months in test and control groups were 93.60% and 93.70%,respectively.The sizes of breast,uterus and ovary of children and the levels of estradiol （E2） were significantly reduced,and the growth rate of BA was also reduced.All the differences between pre-and post-treatment in each group were statistically significant （P 〈 0.05）,but the differences of the parameters between two groups were not significant （P 〉 0.05）.Conclusions：Domestic leuprorelin is effective and safe in the treatment of Chinese girls with ICPP.Its effectiveness and safety are comparable with imported leuprorelin.