Analysis of Drill Pipe Failure Mechanism in SHYB-583 Well in Saudi Arabia

Aiming at the problem of drill pipe washout in the SHYB583 well in Saudi Arabia, the failure mechanism of drill rod is studied by analyzing the physical and chemical properties of thickened transition zone, stress analysis of transition zone under the combined action of tension, bending and torsion, flow field characteristics of inner channel, dynamic characteristics and fatigue analysis of drill string under the condition of actual well trajectory. The results show that the thickness of some parts of the coating of the failed drill pipe sample does not meet the requirements of SY/T 0544-2010 technical conditions for internal coating of petroleum drill pipe (seriously thin), and the drill pipe material contains high index nitride, which reduces the impact toughness of the drill pipe, thus reducing the fatigue life of the drill pipe. Under the combined load, the transition section of the drill pipe has a high stress level, and there is a significant eddy current near the transition zone, and the total pressure of the drill pipe caused by the internal flow field is large. The drill string does not produce more severe whirl, and the amplitude of axial vibration and transverse vibration is small, but the vibration frequency of bending stress is twice of the rotation frequency of the drill string. The large dogleg of the failed drill string increases the bending stress, which makes the drill string more prone to fatigue failure

An alternative approach to the σ\sigma-meson-exchange in nucleon-nucleon interaction

Through a quantitative comparative study of the properties of deuteron and nucleon-nucleon interaction with chiral quark model and quark delocalization color screening model. We show that the $\sigma$-meson exchange used in the chiral quark model can be replaced by quark delocalization and color screening mechanism.Comment: 4 pages, 4 figure

Sequence Dependent Structural Transition of Short DNA by Tensile Force

Del 25 de novembre de 2013 al 3 de febrer de 201

A case report of atypical chronic myeloid leukemia with complete hematological and major molecular response to Venetoclax/Azacitidine treatment

Atypical Chronic Myeloid Leukemia (aCML), a myeloproliferative neoplasm with poor prognosis, was reclassified as aCML by the ICC classification, and as MDS/MPN with neutrophilia by the WHO 2022 classification. Due to the heterogeneity of its clinical features and the lack of unique biomarkers, as well as limited treatment options, aCML currently lacks a standardized treatment protocol. In this case report, we reviewed a young man diagnosed with aCML who achieved complete clinical and hematologic remission subsequent to receiving a therapeutic regimen combining Venetoclax and Azacitidine

Predictions of the Strange partner of TccT_{cc} in the quark delocalization color screening model

Inspired by the detection of $T_{cc}$ tetraquark state by LHCb Collaboration, we preform a systemical investigation of the low-lying doubly heavy charm tetraquark states with strangeness in the quark delocalization color screening model in the present work. Two kinds of configurations, the meson-meson configuration and diquark-antidiquark configuration, are considered in the calculation. Our estimations indicate that the coupled channel effects play important role in the multiquark system, and a bound state with $J^{P}=1^{+}$ and a resonance state with $J^{P}=0^{+}$ have been predicted. The mass of the bound state is evaluated to be $(3971\sim3975)$ MeV, while the mass and width of the resonance are determined to be $(4113\sim4114)$ MeV and $(14.3\sim 16.1)$ MeV, respectively.Comment: 12 pages, 4 figure, 7 table