【作者】 刘长运；

【导师】 赵学增；

【作者基本信息】 哈尔滨工业大学 ， 机械电子工程， 2007， 博士

【摘要】 分层注水是目前我国应用最为广泛的提高石油采收率的方法,对我国的石油增产稳产具有重要意义,其中分层流量控制是分层注水方法的核心技术之一。随着中老油田开发过程中注采不平衡问题的积累和非均质复杂断块油层的开发,使得油田井层间渗透率和压力产生不平衡,这要求分层注水方法的分层更加细化,而传统固定水嘴堵塞器存在测调工作量大和流量受地层和注水压力影响的缺点,因此急需新的替代技术以适应当前注采工艺的要求。恒流堵塞器具有测调工作量小、结构简单及成本低等优点,是一种理想的分层注水流量调节方法。但现有恒流堵塞器存在流量调节精度较低和使用可靠性较差的缺点。针对这一问题,本文结合黑龙江省科学技术攻关项目“分层注水恒流堵塞器的研制”(编号:GC05A508),利用机械、电子和材料等学科的理论,并采取计算机模拟、地面和井下试验等分析手段,研制出一种新型分层注水恒流堵塞器。本文提出了先减压式恒流堵塞器结构,分析了其在内泄漏和振动特性等方面的优点。充分考虑了内泄漏、阻尼力、液压卡紧力及局部流场分布等因素的影响,采用键合图理论,建立了先减压式恒流堵塞器的动力学模型,为分析其静动态特性提供了基础。建立了先减压式恒流堵塞器的计算流体力学与键合图理论相结合的混合仿真方法,对先减压式恒流堵塞器的静态特性和稳定性进行了分析。试验表明,仿真结果准确可靠。同时还对该恒流堵塞器的结构进行了优化与改进,在控制好加工成本的基础上,使其静动态特性满足了实际应用要求。对恒流堵塞器的主要失效形式进行了研究,在流体-颗粒两相流理论、颗粒动力学、三体磨损与污染卡紧理论的基础上,建立了污染磨损和卡紧的数值模拟方法。在Matlab平台上对先减压式恒流堵塞器的污染磨损和卡紧进行了计算,比较了配合间隙、阀芯振动的影响。同时,还研究了该恒流堵塞器的阀口冲蚀和阀内气蚀,采用Fluent软件对冲蚀和气蚀进行了数值模拟,分析了二者对该恒流堵塞器流量特性的影响。模拟结果与实际相符,可为结构优化提供依据。搭建了恒流堵塞器地面试验台,对先减压式恒流堵塞器的流量特性和可靠性进行了试验。在综合分析、计算和试验的基础上确定了恒流堵塞器的结构、材料和关键部位表面处理方法。结果表明所采用的理论和数值模拟方法可有效地对恒流堵塞器的流量特性和可靠性指标进行分析,所研制的恒流堵塞器在流量调节精度和可靠工作寿命等方面都可以满足油田分层注水技术的要求。本文还提出了将恒流堵塞器和井下分层测调仪结合使用的分层注水流量调配方式,分析了该方案的可行性,对具体实施方案、机械结构、电路组成和软件结构进行研究。更多还原

【Abstract】 The separated layer water injection is the most popular EOR (Enhanced Oil Recovery) technology in China now, and it is of far reaching importance for the increasement and stabilization of the petroleum production. The flow control of each layer is a key matter of this technique. With the enhancement of the voidage-injection imbalance and the exploitation of the complicated heterogeneous fault-block oil field, the confliction among wells or layers is becoming more and more serious. This leads to the gradual increasement of the layers in the water injection scheme. But the conventional fixed-nozzle blanking plug has many defects such as the hard work of the flow measure and adjustment, instable water flow rate and so on. So the requirement for new technique is urgent now.The constant flux blanking plug has many advantages such as convenient application, simple structure and low cost. But current constant flux blanking plugs have some problems in the flow characteristics and reliability. This raises the difficulty of the application. Based on theories in the mechanical engineering, electronic engineering and materials engineering together with the methods such as the theoretical analysis, computer simulation and experimental analysis, a new type downhole constant flux blanking plug has been developed. This research is financed by the Heilongjiang Key Science and Technology Project of China“Research and Development on the Constant Flux Blanking Plug Used in the Separated Layer Water Injection”(GC05A508).The pressure-reducing first constant flux blanking plug has been put forward, and its merits in internal leakage and vibration are analyzed. The kinetic model of the constant flux blanking plug has been established with the full consideration on the influence of the leakage, damping force, hydraulic lock force, and local flow field, which provides the theory foundation for research the static or dynamic characteristics of the pressure-reducing first constant flux blanking plug.The mixed-simulation method on the pressure-reducing first constant flux blanking plug has been brought forward on the basis of the computational fluid dynamics and hydro-mechanics. The static characteristic and stability of the pressure-reducing first constant flux blanking plug have been analyzed by this simulation method. The experiments show that the simulation results are precise and reliable. The structural optimization has been done effectively to reduce the production cost and enhance the flow control precision.The main failure mechanisms of the constant flux blanking plug have been studied. The contaminant wear and lock simulation method has been established based on the theories of fluid-particle two phase flow, particle dynamics, contaminant wear and contaminant lock. The simulations on the wear rates and lock forces have been done using the Matlab software. And the influences of the clearance height and valve spool vibration have been studied. The particle-induced erosion near valve ports and cavitation in the valve pocket have been calculated by the Fluent software, and their influences on the flow characteristic have been analyzed. The simulation results are reasonable and helpful to the design.The test bench has been designed, and the properties including the flow characteristic and reliability of the pressure-reducing first constant flux blanking plug have been tested by ground and downhole experiments. The structures, materials and surface treatment of the constant flux blanking plug have been optimized on the basis of the theoretical analysis, simulation and experiments to achieve better combination property. The experimental results show that: i) the adopted theoretical and numerical methods are effective in the analysis of the flow characteristic and the reliability; ii) the designed constant flux blanking plug has high performance both in the flow control precision and in the service life.A new type downhole flow regulating scheme which combines the constant flux blanking plug and downhole testing and regulating system has been brought forward. The practicability has been analyzed, and the preliminary studies on the overall scheme, machine construction, circuit framework, software configuration have been done.更多还原