Ocean floating drill platform string heave compensation device

Abstract

The invention discloses a novel drill stem heave compensation device for an ocean floating type drilling platform. A combined type hydraulic cylinder is adopted as a heave compensation hydraulic cylinder. The high-pressure hydraulic oil outputted from a hydraulic pump is led into a non-rod cavity of the inner casing of the combined type hydraulic cylinder through a compensation control valve, and therefore a controllable subsidiary force is provided for an outer casing piston rod. The controllable subsidiary force and the pressure of an accumulator acted by a non-rod cavity of the outer casing of the compensation hydraulic cylinder jointly form a support force for a hook load. The subsidiary force is controlled according to the heave movement of the platform, thereby improving the heave compensation effect of a conventional driven type system. According to the detected movement speed of the platform in the vertical direction, a control unit gives a control command to the hydraulic system so as to drive a piston of the compensation hydraulic cylinder to drive a sprocket to move, thereby compensating the heave movement of the platform under a chain or the chain action, and consequently enabling a cross beam and the hook to be in a static status relative to a hole bottom in the vertical direction within an allowable range. The drill stem heave compensation device can effectively control the consumption of the energy, reduce the operating cost of the system, and improve the compensation precision.

Description

technical field [0001] The invention relates to a hydraulic control system characterized by electro-hydraulic control technology, in particular to a heave compensation device for a drill string of an ocean drilling platform. Background technique [0002] With the depletion of land resources, the strategic vision of the world's economic development is focused on the ocean, and the development of marine technology and high-tech equipment is particularly important. In the field of petroleum, with the development of China's economy, especially the rapid development of the petrochemical and automobile industries as the pillar industries, the contradiction of insufficient supply of oil and natural gas has become increasingly prominent. In view of the depletion of onshore oil resources, marching into the deep sea has become an inevitable trend. At present, the maximum working water depth of offshore oil drilling rigs has exceeded 3000m, and will continue to develop in a deeper dir...

AI Technical Summary

Problems solved by technology

[0005] The active heave compensation system has good compensation effect and strong adaptability, but due to the large mass of the drill string and frequent up and down reciprocating movements, a large amount of energy will be consumed in the compensation process

[0006] The passive heave compensation system basically does not require the system to provide additional energy during the compensation process, and the system is simple and has been widely used, but the compensation effect is not very ideal, and there is a certain hysteresis phenomenon

[0007] The semi-active heave compensation system can combine the advantages of both, but the system structure is more complicated and the manufacturing cost is higher

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