【摘要】 深水区地层普遍存在窄安全密度窗口的特性，显著增加了钻井作业中井下压力控制的难度，严重制约了深水油气资源的高效开发。针对该技术瓶颈，本文基于理论分析与数值模拟相结合的方法，系统探究了深水双层管双梯度钻井技术体系下井底压力动态调控机制。建立了钻井水力学参数与井底压力的耦合计算模型，分析了钻进过程中井底压力的变化规律，揭示了钻井泵排量、举升泵扬程和井底压力三者之间的关系；通过海上试验验证调节举升泵流量可精准控制钻井液当量密度，实现井底压力的主动调控。本研究通过调节举升泵流量调控井底压力，基于环空隔离液液位变化动态调整扬程，实现钻井液当量密度精准控制，以期保障深水钻井安全并支撑油气高效开发。更多还原

【Abstract】 Deepwater formations commonly exhibit the characteristic of a narrow safe mud weight window, which significantly increases the difficulty of bottom-hole pressure control during drilling operations, severely restricting the efficient development of deepwater hydrocarbon resources. To address this technical bottleneck, this study systematically investigated the dynamic bottom-hole pressure control mechanisms within the deepwater double-layer pipe dual-gradient drilling(DGD) system through a combination of theoretical analysis and numerical simulations. By building a coupled computational model linking drilling hydraulics parameters and bottom-hole pressure, the study analyzed the pressure variation patterns during drilling, revealing the interrelationships between drilling pump displacement, lift pump head, and bottom-hole pressure. Offshore field tests demonstrate that regulating lift pump flow rates can precisely control the equivalent density of drilling fluid, achieving active bottom-hole pressure regulation. This research proposes a method for regulating bottom-hole pressure by adjusting lift pump flow rates while dynamically adjusting the pump head based on annulus spacer level changes, ensuring precise control of drilling fluid equivalent density. These advancements enhance drilling safety in deepwater environments and support efficient hydrocarbon resource development.更多还原