Xinyu Dou

Based on a comprehensive analysis of the existing methods for measuring adjacent well distances, along with their advantages and disadvantages, this study employs theoretical analysis, simulation experiments, and other comprehensive research methods to investigate a distance measurement method based on current excitation. In response to the need for measuring and controlling the connection of relief wells, a method utilizing dual-electrode current excitation during drilling is proposed. This approach facilitates synchronous excitation measurements while drilling, significantly reducing both time and costs while ensuring safety and efficiency, making it particularly suitable for the connection operation of relief wells that involve safety risks. Firstly, this paper establishes a drilling with measurement model corresponding to the excitation mode, which derives the calculation formulas for the target casing current amplitude attenuation, as well as the induced magnetic field distribution within the formation. Additionally, it provides the calculation methods for determining the target well distance and azimuth direction. Lastly, the impact levels of various key factors are verified through numerical calculations and simulation analyses, which confirm the correctness and effectiveness of this distance measurement method. The findings from this research establish both a core theoretical foundation and a technological basis for the real-time measurement of adjacent well distances during relief well operations.

Conventional adjacent wells range scanning calculations cannot meet the accuracy demands of the anticollision measurement of borehole distances any longer. Current techniques commonly employ electromagnetic detection tools while drilling; this requires putting equipment down adjacent wells to avoid collision risks, which adds more workload and costs and sometimes even affects the normal production of the producing wells. Measuring and tracking adjacent borehole distances while drilling is an essential process that guides the drill bit and effectively avoids collisions with existing wells. This paper proposes an active anticollision method of rotating magnetic ranging based on double symmetrical magnetic sources with opposite magnetic moments. First, the proposed method uses magnetic sources in the drilling well that are built into the probe tube to generate a magnetic field; then, the ferromagnetic casing of the existing well would be magnetized by the abovementioned magnetic field; finally, the magnetization field of the ferromagnetic casing is measured by a triaxial magnetometer built into the probe tube to determine the spacing and position of the existing well. Simultaneously, the calculation models of magnetic flux density around the casing of the existing well and magnetic sources are established, the calculation formulae of the relative distance and position of two adjacent wells are deduced, and a new variable interval section segmentation is proposed based on the Cosine theorem. The simulation results demonstrate that the spacing and position of the existing well are determined based on the magnetic sources’ spacing inside the probe, the magnetic moment of the magnetic sources, the relative permeability of the casing, the diameter of the casing, and the inclination between the drilling well and the existing well. The validity and accuracy of the active magnetization model are confirmed, providing theoretical support for the further development of electromagnetic anticollision devices.

To establish a tradeoff between complexity and performance of frequency estimation of sinusoidal signals, a novel automatic segmentation-improved Quinn–Rife method is proposed. The proposed method first utilizes a Discrete Fourier Transform (DFT) algorithm to obtain a coarse estimation, and then divides the frequency deviation into three domains with different processing schemes, which could be suitable for low-delay applications. Simulation results show that the proposed method can overcome the inherent flaws of the classic Quinn and Rife methods, and that the root mean square error closely approaches the Cramer–Rao lower bound at a low signal-to-noise ratio with different estimation ranges. Furthermore, the method does not significantly increase the computational cost under the premise of guaranteed performance, which is beneficial for engineering applications.

A new package structure based on printed circuit board (PCB) as carrier substrate was proposed, aiming at providing an implementation of system-in package (SiP) emphasizing small size and more importantly low cost. This structure is built upon a multilayer PCB, where open cavities are created in the top and bottom layers to house active dies, allowing package size reduction as well as protection against handling and impact. An application prototype was devised to integrate an RF IC and a baseband digital IC, typical of a wireless communication Rx system. Thermo-mechanical simulation models of the prototype are constructed to comparably assess certain aspects of its reliability and manufacturability. The results show comparable thermal performance compared with currently mainstream substrate material. Thermal cycling test of the new structure to experimentally evaluate its reliability is planned with results to be reported in a separate report.

Wafer level packaging (WLP) technology has been used to integrate high-Q inductor on Si substrate. These inductors consist of a thick Cu electroplated rerouting to reduce series resistance and a thick dielectric layer to separate the inductors from Si substrate. The measured results show that the peak O-factor is 30 at 4 GHz for a 0.77 nH inductor, which is good agreement with the simulated performance by HFSS. Therefore, this technology realizes embedded high-Q inductors in WLP and can improve the performance of RF system.