Research And Design Of The Mechanism Of Deep Sea Drilling Heave Compensation Device

In the process of deep water drilling operation, the floating drilling platform can produce six degrees of freedom of complex movement like the heave, vertical swing, sway, flat rocker, roll and pitching under the action of waves or other natural load, and heave movement has the biggest influence on drilling operation. The heave motion of drilling platform causes the hook tension fluctuation, and effect of the bit drilling pressure stability of bottom hole rock, and reduces the efficiency of drilling greatly, the service life of bit and drill string columns with periodic variation under load decrease, and make the cost of whole drilling increases. In order to avoid the above situation, A device which is called the heave compensation device and is installed on the offshore drilling platform that has the capable of realizing the motion compensation function of the drill string.The performance of heave compensation device directly affects the efficiency and safety of deepwater drilling, this kind of device is an important part of the deepwater drilling equipment, and has always been highly valued by the deepwater drilling industry at home and abroad, at present, foreign products have been put into practical field application in the deepwater drilling operations. But how to according to the different condition of deepwater drilling requirements to design more reliable, high efficiency, strong adaptability and simple operation of the compensation device, and that is still one of the key to the development of deepwater drilling equipment technology.At present, the heave compensation system of china on deepwater drilling platform are required to be imported from abroad at high price, the relevant design and manufacturing technology of the heave compensation device is not yet mastered temporarily in China. Therefore, working hard to study on the dynamics of deep water drilling system, and to find the movement rules and mechanical characteristics of the drill string system and heave compensation device in the deepwater drilling process, on this basis, developed a kind of crane-block heave compensation device for our floating deepwater drilling platform with independent intellectual property in China. It is the key technical and equipment support for the realization safe and high efficiency of deepwater drilling operation in our country.In this paper, extensive research at home and abroad based on heave compensation device equipment design and the related theoretical research on the status quo, through analysis and comparison of structure characteristics, principle and field application of the heave compensation device existing, and found that the crane-block heave compensation system is a kind of heave compensation device that was widely used and has high degree of mature technology, and also has the further improvement of the design value. The crane-block heave compensation device to carry out a series of research work as a main research object in the paper, the main research contents include the following several aspects:(1) Through extensive access and retrieval of relevant documents at home and abroad, the research results of the equipment development status and related motion compensation technology were investigated deeply, on this basis, according to the current development situation and the problem of deepwater drilling heave compensation device, put forward the research direction and ideas of this paper.(2) The load analysis and motion response of the floating drilling platform heave motion were simulated and studied. The effect of drilling platform heave motion on the drilling operation is analyzed, and analysis effect of the drilling operations to the drilling platform heave motion,and load analysis and calculation of wave exciting force including the platform buoyancy variation, platform inertia force and resistance, inertia force and frictional resistance of platform column in the plane of floating drilling platform heave motion, and simulation of the movement response of floating drilling platform by using AQWA software.(3) The vibration dynamics and displacement of this device and drill string system were analyzed. According to the vibration characteristics of the heave compensation device in the course of motion compensation, the finite element method was used to establish the dynamic model of heave compensation device and drill string in the plane of heave motion, this model belongs to a forced vibration system with only one degree of freedom and viscous damping, and the vibration displacement and displacement at the lower end of the drill string were analyzed, using the 20-sim software to simulation analysis of the friction factors for the crane-block heave compensation system in the process of compensation, and to provide a theoretical basis for further structural design of crane-block heave compensation device.(4) Carry out a new scheme design of crane-block heave compensation device. In the analysis of crane-bolck heave compensation device on the working mechanism,and combine with the main design parameters of device, put forward a scheme design of this system with a new type of mechanical driven.(5) Carry out structure design and simulation analysis of a new crane-block heave compensation device. On the basis of the plan design, the new kind of crane-block heave compensation device with locking guide device, driving gear-straight rack track with active mechanical driving mechanism and wire rope rocker mechanism with passive compensation function were detailed structure parameter calculation and hydraulic pipeline designed. And using the Matlab mathematical analysis software, Abaqus simulation software and AMEsim hydraulic simulation software, to simulation analysis and verification of the motion meshing process of the gear rack driving mechanism, and the hydraulic circuit and the structural strength of locking guide device, and the passive compensation function of the wire rope rocker mechanism in the crane-block heave compensation device.In summary, this paper on the basis of the extensive research of equipment development situation and literature, and put forward a new type design of crane-block heave compensation device with mechanical driven, its structure design and simulation research of working mechanism have been completed, to verify the feasibility of the new crane-block heave compensation device, it is very great significance to achieve this kind of device localization.