本文提出了一种新型的自适应鲁棒损失函数,显著提高了同步定位与建图(Simultaneous Localization and Mapping,SLAM)算法在高噪声和异常值环境下的精度和稳定性。具体贡献如下:通过引入形状参数和尺度参数,实现了损失函数对不同数据分...本文提出了一种新型的自适应鲁棒损失函数,显著提高了同步定位与建图(Simultaneous Localization and Mapping,SLAM)算法在高噪声和异常值环境下的精度和稳定性。具体贡献如下:通过引入形状参数和尺度参数,实现了损失函数对不同数据分布的自适应,增强了对噪声和异常值的抵抗力;在多个公开数据集上进行的实验和仿真结果显示,本文方法与传统的平方损失函数和其他鲁棒损失函数(如Huber损失、Geman-McClure损失)相比,在精度和鲁棒性上均提高了15%~20%。这些结果突显了新方法在复杂环境下的应用潜力和优势。展开更多
To seek effective ways of lowering development cost and tapping inter-well remaining reserves, sidetracking horizontal wells from old wells in Su10 and Su53 Block were conducted. The engineering and geological problem...To seek effective ways of lowering development cost and tapping inter-well remaining reserves, sidetracking horizontal wells from old wells in Su10 and Su53 Block were conducted. The engineering and geological problems such as leakage, collapse and sticking in slim-hole sidetracking, and difficult evaluation of remaining gas were gradually overcome, and a set of drilling and completion technology, well deployment optimization technology and geo-steering technology suitable for sidetracking horizontal wells in tight sandstone gas reservoirs have been worked out. By making full use of the old well, sidetracking horizontal wells can greatly reduce development costs, enhance the producing degree of inter-well remaining reserves, and get production 3-5 times of that of adjacent vertical wells.Its production effect is influenced by encountered sandstone length, the position of the horizontal segment in the reservoir, produced effective reservoir thickness, gas saturation, controlled reserves and fracturing effect, etc. Up to now, in Block Su10 and Su53, 12 sidetracking horizontal wells have been drilled, which have an average drilling cycle of 49 days, average horizontal section length of 689 m,average effective drilling ratio of 61.5%, average well-head pressure of 16.2 MPa, and daily output of 4.7×10~4 m^3 at the initial stage after production. By the end of 2017, the average yield increment was more than 1 000×10~4 m^3 with good effect. With the increase of low yield old wells, wells in the enrichment regions tend to be saturated and the rest gas-bearing areas are lower in grade, therefore, sidetracking horizontal well can be used for optimization of well pattern, well deployment mode and exploitation of remaining oil areas.展开更多
文摘本文提出了一种新型的自适应鲁棒损失函数,显著提高了同步定位与建图(Simultaneous Localization and Mapping,SLAM)算法在高噪声和异常值环境下的精度和稳定性。具体贡献如下:通过引入形状参数和尺度参数,实现了损失函数对不同数据分布的自适应,增强了对噪声和异常值的抵抗力;在多个公开数据集上进行的实验和仿真结果显示,本文方法与传统的平方损失函数和其他鲁棒损失函数(如Huber损失、Geman-McClure损失)相比,在精度和鲁棒性上均提高了15%~20%。这些结果突显了新方法在复杂环境下的应用潜力和优势。
文摘在移除二进制偏移载波(Binary Offset Carrier,BOC)信号跟踪模糊的同时,为了保持BOC信号高的码跟踪精度,提出基于加权鉴别函数(Weighted Discriminator Function,WDF)的BOC信号无模糊跟踪方法。WDF使用非相干超前减滞后功率(Noncoherent Early Minus Late Power,NELP)鉴别器和子载波相位消除(Sub Carrier Phase Cancellation technique,SCPC)鉴别器,生成无误锁点的鉴别函数实现BOC信号跟踪。针对BOC(10,5)信号,仿真结果表明,相比于SCPC、基于伪相关函数的无模糊延迟锁定环(Pseudo correlation function based Unambiguous Delay Lock Loop,PUDLL)方法和对称脉冲模糊移除(Symmetrical Pulse Ambiguity Removing,SPAR)方法,所提WDF方法在码跟踪误差方面分别改善了2.5dB、5.5dB与8.3dB,多径误差分别降为60.4%、32.8%与38.0%。因此,WDF是一种有效的、高性能的BOC信号无模糊跟踪方法。
基金Supported by the Project of Great Wall Drilling Company in CNPC(2015A25-2(2012))
文摘To seek effective ways of lowering development cost and tapping inter-well remaining reserves, sidetracking horizontal wells from old wells in Su10 and Su53 Block were conducted. The engineering and geological problems such as leakage, collapse and sticking in slim-hole sidetracking, and difficult evaluation of remaining gas were gradually overcome, and a set of drilling and completion technology, well deployment optimization technology and geo-steering technology suitable for sidetracking horizontal wells in tight sandstone gas reservoirs have been worked out. By making full use of the old well, sidetracking horizontal wells can greatly reduce development costs, enhance the producing degree of inter-well remaining reserves, and get production 3-5 times of that of adjacent vertical wells.Its production effect is influenced by encountered sandstone length, the position of the horizontal segment in the reservoir, produced effective reservoir thickness, gas saturation, controlled reserves and fracturing effect, etc. Up to now, in Block Su10 and Su53, 12 sidetracking horizontal wells have been drilled, which have an average drilling cycle of 49 days, average horizontal section length of 689 m,average effective drilling ratio of 61.5%, average well-head pressure of 16.2 MPa, and daily output of 4.7×10~4 m^3 at the initial stage after production. By the end of 2017, the average yield increment was more than 1 000×10~4 m^3 with good effect. With the increase of low yield old wells, wells in the enrichment regions tend to be saturated and the rest gas-bearing areas are lower in grade, therefore, sidetracking horizontal well can be used for optimization of well pattern, well deployment mode and exploitation of remaining oil areas.
