Isolated underwater flexible storage device for offshore oil and gas fields

Abstract

The invention discloses an isolated underwater flexible storage device for an offshore oil-gas field. The device comprises a sealed storage tank and a plurality of storage units, wherein the plurality of storage units are vertically arranged and fixedly connected in the sealed storage tank; the sealed storage tank is provided with a water pipe which is communicated with the outside; each storage unit is provided with a flexible soft bag and an open-type jacket; each flexible soft bag is provided with a medium loading-unloading pipeline; each medium loading-unloading pipeline is fixed on the corresponding open-type jacket. The device disclosed by the invention has the advantages that the main advantages of a dry oil storage method are reserved, crude oil or other liquid hydrocarbon compounds are not in direct contact with seawater, the effect of heat preservation can be achieved, and water soluble liquid, such as methanol, can be stored; meanwhile, two disadvantages of the dry oil storage method are overcome; the effects of safety, environmental friendliness and suitability for different water depths are achieved; the flexible soft bag is used for storing a medium, so that the separation between the medium and water is realized, and the effects of high volume utilization ratio and low cost are achieved.

Description

technical field [0001] The invention belongs to the field of offshore oil and gas development, in particular to an isolated underwater flexible storage device used in offshore oil and gas fields. Background technique [0002] There are two ways to carry out follow-up processing after crude oil is produced in offshore oil fields: 1) export it with submarine pipelines; 2) store it in an oil storage device and regularly transport it out with a shuttle tanker, which can be a fixed part of the production platform , can also be a single structure. If the production of an offshore oil field is not large enough, the cost of laying expensive submarine oil pipelines will outweigh the benefits. In this case, the only way to exploit it is to use some kind of low-cost but safe and reliable oil storage device. [0003] Exactly where the oil storage unit is placed matters a lot. There are only three optional positions: 1) above the waterline and fixed in the upper layer of the platform; ...

AI Technical Summary

Problems solved by technology

The second is heat insulation. Oil needs to be heated to keep it in a liquid state, while the water coming in from the outside is cold. Therefore, it is difficult to take heat preservation measures for crude oil when oil and water are in contact with a large area.

Third, the method cannot store water-soluble liquids such as methanol

The cement structure directly sits on the bottom, which is prone to bottom scour and hollowing out, which poses hidden dangers to the safety of the platform

Second, due to the presence of seawater ballast tanks, the overall weight of the device is increased

Third, the effective operation of the entire oil storage device depends on a complex combined pump system that can simultaneously pump and discharge the crude oil or seawater in the oil storage tank and the ballast tank. This system has potential safety hazards for long-term reliable operation.

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