Perforation optimization of hydraulic fracturing of oil and gas well

Zhu, Hai Yan,Deng, Jin Gen,Chen, Zi Jian,An, Feng Chen,Liu, Shu Jie,Peng, Cheng Yong,Wen, Min,Dong, Guang Techno-Press 2013 Geomechanics & engineering Vol.5 No.5

Considering the influences of fluid penetration, casing, excavation processes of wellbore and perforation tunnels, the seepage-deformation finite element model of oil and gas well coupled with perforating technique is established using the tensile strength failure criterion, in which the user-defined subroutine is developed to investigate the dynamic evolvement of the reservoir porosity and permeability. The results show that the increases of perforation angle and decreases of perforation density lead to a higher fracture initiation pressure, while the changes of the perforation diameter and length have no evident influences on the fracture initiation pressure. As for initiation location for the fracture in wellbore, it is on the wellbore face while considering the presence of the casing. By contrast, the fractures firstly initiate on the root of the tunnels without considering casing. Besides, the initial fracture position is also related with the perforation angle. The fracture initiation position is located in the point far away from the wellbore face, when the perforation angle is around $30^{\circ}$; however, when the perforation angle is increased to $45^{\circ}$, a plane fracture is initiated from the wellbore face in the maximum horizontal stress direction; no fractures was found around perforation tunnels, when the angel is close to $90^{\circ}$. The results have been successfully applied in an oilfield, with the error of only 1.1% comparing the fracture initiation pressure simulated with the one from on-site experiment.

Effect of In-situ TiC particles on the microstructure and mechanical properties ofAl8.5Fe1.4V1.7Si aluminum alloy

Baohong Zhu,Yong’an Zhang,Baiqing Xiong,Hongwei Liu,Likai Shi,Songxiao Hui 한양대학교 세라믹연구소 2006 Journal of Ceramic Processing Research Vol.7 No.2

Heat-resistant Al-Fe-V-Si aluminum alloys enhanced by in-situ TiC particles have been prepared by spray forming process with suitable process parameters. Research results show that the microstructure of the as-deposited alloy is fine and homogeneous. In-situ TiC particles prevent the unstable phases from coming into being. On the other hand, the TiC particles increase the volume fraction of heat-resistant phases. So the mechanical properties of the reinforced alloy by in-situ TiC particles are better than that of Al-Fe-V-Si alloy without the TiC particles. The hot extrusion temperature is also an important parameter to be considered. It is proved better to extrude the alloy at lower temperature. The tensile strength of the alloy without TiC particles is about 435 MPa at room temperature and is about 204 MPa at 350oC. However, when the alloy is enhanced by in-situ TiC particles, the strength of alloy is about 482 MPa at room temperature and is about 224 MPa at 350oC.

네트워크 외부성, 지각된 품질, 지속적 사용의도: 전환비용의 조절효과에 관한 연구

안설주(An, Xue-zhu),황용철(Hwang, Yong-Cheol) 한국비즈니스학회 2020 비즈니스융복합연구 Vol.5 No.1

Microstructures and Properties of Molybdenum Wire Doped with Minim La2O3

Li DaCheng,Bu Chunyang,Zhu Yong-An,Wang Jin 한국분말야금학회 2006 한국분말야금학회 학술대회논문집 Vol.2006 No.1

The microstructures and properties of pure molybdenum wire and Mo-La2O3 alloy wire annealed at different temperatures are investigated systematically in this paper. It is shown that the recrystallization temperature, toughness and strength at room temperature of this wire was increased greatly by addition of La2O3. The room temperature embrittlement of this wire annealed at high temperature is improved remarkably.

EXPLOSIVE CONSOLIBATED SICp/Al-Li COMPOSITE AND ITS MICROSTRUCTURE

Shao, Shao, Wen-Zhu,An, An, Xi-Yong 한국재료학회 1995 Fabrication and Characterization of Advanced Mater Vol.2 No.4

Blanks of SiCp/Al-Li composite were produced by way of powder explossion consolidation method which has been optimized in parameter thriugh expoeriment. By SEM, it was found that the microstructure of this composite has following characteristics : (1) SiC particles are uniformlu distributed in the composite ; (2) Al-Li powders still remain original dendrite structure ; (3) There is some metalluryical bonding between composite particles ; (4) hine particles deform or milt preferentiallu and along some direction deformation of Al-Li particles ; (5) SiCp/Al-Li composite is composed of two kind of Al-Li pweders with very different size ; (6) press-torsion, pressless sinter and hot is static press treatment will make original dendrite in Al-Li particles disappear, further enlargi metallurgical bonding region and incress the dinsity of composite.

Single Nucleotide Polymorphisms of Toll-Like Receptor 7 and Toll-Like Receptor 9 in Hepatitis C Virus Infection Patients from Central China

Xin-su Wei,Ping-an Zhang,Chuan-dong Wei,Yong-qing Tong,Cheng-liang Zhu 연세대학교의과대학 2014 Yonsei medical journal Vol.55 No.2

Purpose: To analyze the correlation of polymorphisms of toll-like receptor 7 (TLR7) (rs179009) and toll-like receptor 9 (TLR9) (rs187084) in hepatitis C virus (HCV) infections in the Han population. Materials and Methods: The genotypes of TLR7IVS2-151 in HCV infection were detected by Sanger sequencing using polymerase chain reaction-restriction fragment length polymorphism to determine the TLR9 T-1486C single nucleotide polymorphisms (SNP) for all enrolled patients. Results: We found no significant difference between males with spontaneousclearance of HCV versus those chronically infected [χ²=2.71, p=0.10, odd ratios(OR)=0.58, 95% confidence interval (CI) 0.31-1.11]. However, significant differences were found for the distribution of TLR7 (rs179009) in females (χ²=9.46, p=0.01). In females, a significant difference was also found between chronic hepatitis C and those with spontaneous clearance of HCV in terms of TLR7 IVS2-151G/A allele frequencies (χ²=9.50, p=0.00, OR=0.46, 95% CI 0.28-0.75). In HCV-infected patients, no significant association was found between the frequency of TLR9 genotypes and alleles. Conclusion: The site of TLR7 IVS2-151 (rs179009) G/A may be a factor for susceptibility of chronic HCV in the femaleHan population. TLR9T-1486C (rs18084) SNP may not play a major role in HCV infection. However, individual risk profiles for HCV infection did vary by sex and this relationship should be further investigated.

A Retrospective Study of the Effect of Spinopelvic Parameters on Fatty Infiltration in Paraspinal Muscles in Patients With Lumbar Spondylolisthesis

Jia-Chen Yang,Jia-Yu Chen,Yin Ding,Yong-Jie Yin,Zhi-Ping Huang,Xiu-Hua Wu,Zu-Cheng Huang,Yi-Kai Li,Qing-An Zhu 대한척추신경외과학회 2024 Neurospine Vol.21 No.1

Objective: The effect on fat infiltration (FI) of paraspinal muscles in degenerative lumbar spinal diseases has been demonstrated except for spinopelvic parameters. The present study is to identify the effect of spinopelvic parameters on FI of paraspinal muscle (PSM) and psoas major muscle (PMM) in patients with degenerative lumbar spondylolisthesis. Methods: A single-center, retrospective cross-sectional study of 160 patients with degenerative lumbar spondylolisthesis (DLS) and lumbar stenosis (LSS) who had lateral full-spine x-ray and lumbar spine magnetic resonance imaging was conducted. PSM and PMM FIs were defined as the ratio of fat to its muscle cross-sectional area. The FIs were compared among patients with different pelvic tilt (PT) and pelvic incidence (PI), respectively. Results: The PSM FI correlated significantly with pelvic parameters in DLS patients, but not in LSS patients. The PSM FI in pelvic retroversion (PT > 25°) was 0.54 ± 0.13, which was significantly higher in DLS patients than in normal pelvis (0.41 ± 0.14) and pelvic anteversion (PT < 5°) (0.34 ± 0.12). The PSM FI of DLS patients with large PI ( > 60°) was 0.50 ± 0.13, which was higher than those with small ( < 45°) and normal PI (0.37 ± 0.11 and 0.36 ± 0.13). However, the PSM FI of LSS patients didn’t change significantly with PT or PI. Moreover, the PMM FI was about 0.10–0.15, which was significantly lower than the PSM FI, and changed with PT and PI in a similar way of PSM FI with much less in magnitude. Conclusion: FI of the PSMs increased with greater pelvic retroversion or larger pelvic incidence in DLS patients, but not in LSS patients.