哈萨克斯坦01A井钻井技术研究

01A井是位于滨里海盆地的东缘构造带上部署的一口评价井,在钻井过程中钻遇的盐层软硬交错变化、浅层气等给施工造成了许多困难。根据实钻情况及时分析、总结,采取相应的技术措施,克服了钻井施工中出现的难题,完成了钻探任务。     

钻井过程中岩屑运移模型研究进展

随着斜井和水平井数量的不断增加，井眼清洁已成为钻井的关键技术和难题之一。在过去的60多年里，人们对钻井过程中的岩屑运移问题进行了大量的实验和理论研究，对这一课题有了较多的认识，建立了一些模型，为实际钻井过程中水力参数设计提供了有效的依据。本文对描述岩屑运移规律的经验模型和分层理论模型进行了系统的总结，并专门对泡沫携岩模型进行了总结，在此基础上对岩屑运移模型的发展进行展望，最后给出了研究建议，为今后深入开展岩屑运移研究提供参考。     

Microstructure evolution of directionally solidified Ti-45Al-8.5Nb-(W, B, Y) alloys

Intermetallic Ti-45Al-8.5Nb-(W, B, Y) alloys were directionally solidified at constant growth rates (V) ranging from 10 to 400 μm/s under the temperature gradient G = 3.8 × 10³ K/m. Quenching was performed at the end of directional solidification (DS) experiments. Microstructure evolution was investigated by analyzing the microstructures formed at the quenching interfaces and in the DS regions. The primary dendritic arm spacing (λ) decreases with increasing growth rate according to the relationship λ ∝ V^−0.36. Both the width of columnar grain (λw) and the interlamellar spacing (λ_s) decrease with increasing growth rate according to the relationships λw∝V−1.13 and λ_s ∝ V^−0.32, respectively. Lamellar microstructure initially disappears from the dendrites at the growth rate of 100 μm/s and subsequently from the interdendritic regions when the growth rate is up to 200 μm/s. The B2 particles can precipitate in the interdendritic regions.     

Formation and distribution of silicon carbide (SiC) precipitates in industrial directional solidification of mc-Si ingots

Abstract

Silicon carbide inclusions in multicrystalline (polycrystalline) silicon ingots affect the cutting process and quality of silicon wafers. The higher density of SiC inclusions relative to the silicon melt suggests that they should sink, but inclusions were observed at the top, middle and bottom of industrial ingots. More inclusions were observed at the top relative to the middle and bottom of the ingot. Small SiC inclusions were found at the bottom and reticular SiC inclusions at the top of the ingot, suggesting that inclusion growth may occur during growth of the ingot. A mechanism to explain the formation and distribution of SiC in industrial silicon directionally solidified ingots, based on the thermodynamics of SiC, is proposed together with strategies to reduce carbon contamination and improve ingot quality.     

An asymmetric dimension-adaptive tensor-product method for reliability analysis

Reliability analysis plays an essential role in the development of structural systems. However, commonly used reliability analysis methods suffer from either the curse of dimensionality or the lack of accuracy in many structural problems. This paper presents an asymmetric dimension-adaptive tensor-product (ADATP) method to resolve the difficulties of existing reliability analysis methods. The proposed method leverages three ideas: (i) an asymmetric dimension-adaptive scheme to efficiently build the tensor-product interpolation considering both directional and dimensional importance, (ii) a hierarchical interpolation scheme using either piecewise multi-linear basis functions or cubic Lagrange splines, (iii) a hierarchical surplus as an error indicator to automatically detect the highly nonlinear regions in a random space and adaptively refine the collocation points in these regions. The proposed method has three distinct features for reliability analysis: (a) automatically detecting and adaptively reproducing tri- and higher-variate interactions, (b) greatly alleviating the curse of dimensionality, and (c) no need of response sensitivities. Several mathematical and engineering problems involving high nonlinearity are used to demonstrate the effectiveness of the ADATP method.     

基于多孔介质热弹性理论的井壁诱导缝成因

常规纯弹性理论通常把钻井过程中直井井壁诱导缝的形成归结为钻井液密度过高或者水平主应力差值过大,然而该理论却并不能完全合理地解释深井井壁诱导缝的成因。为揭示井壁诱导拉伸缝形成机理,考虑钻井液循环期间低温钻井液与高温井壁围岩的热交换,基于多孔介质热弹性力学理论,建立了适于深部地层的井壁稳定分析模型,研究了流固热耦合作用下的井周周向有效应力、孔隙压力与温度分布计算模型。计算结果表明:(1)在最大水平地应力方位,井眼钻开初期多孔弹性作用居于主导,孔隙压力在近井壁地带出现谷值,对诱导缝的形成起到了抑制作用;(2)然而随着钻井液与地层热交换的进行,钻井液的冷却作用愈加重要,井周周向有效应力由挤压状态逐渐转变为拉伸状态,从而导致近井壁地带诱导缝的形成。结论认为,为避免诱导缝的形成,在工程上一方面需加强钻井液的封堵性,控制液柱压力向井周的扩散;另一方面也可以通过调整优化钻井液密度与流变性能,控制井底钻井液当量密度(ECD)。     

原料全自动取样机在安钢的应用

本文主要对安钢原料进厂取样机的发展史、现状、目前设备存在的问题、设备缺陷的解决措施及未来的发展方向进行探讨。     

岩石可钻性能量法现场实验研究

本文介绍了岩石可钻性能量法在油田现场实验研究的成果：确定其可钻性指标Ｋｎ对地层的适用范围；证明Ｋｎ指标比其他可钻性指标能更容易、更好地反映出井下实际地层可钻性变化情况；用Ｋｎ指标预测钻速与实际钻速接近．     

钻井工程师助手系统的开发应用

本文介绍一种适用于钻井现场工程人员的软件系统──钻井工程师助手，对系统的结构、功能及特点等问题进行了简要的讨论。