Floating production storage and offloading (FPSO) cargo oil tank cleaning method

Abstract

The invention discloses a floating production storage and offloading (FPSO) cargo oil tank cleaning method. The FPSO cargo oil tank cleaning method comprises a first step of undergoing an early preparation stage; a second step of undergoing an air purging cleaning stage, simultaneously performing production water disturbance tank cleaning at the FPSO cargo oil tank air purging stage, and clearing away the tank bottom tank-cleaning water; a third step of undergoing an air removal stage, utilizing more than two fans to feed air, opening tank covers at two ends to alternately exhaust air, and keeping an oil measuring opening and an air measuring opening open; a fourth step of undergoing an inerting stage, adopting a segmented inerting mode for inerting of more than two cabins, first simultaneously performing inerting on all the cabins for 2-3.5h, and then respectively performing concentrated inerting. According to the method, FPSO cargo oil tank cleaning efficiency is improved, the operation risk is reduced, and the operation cost is reduced.

Description

technical field [0001] The invention relates to a tank washing method for offshore production facilities, in particular to a tank washing method for FPSO cargo oil tanks. Background technique [0002] At present, with the development of marine exploration and development to the deep sea, more and more FPSO (Floating Production Storage and Offloading, that is, floating oil storage and offloading devices) have been built and put into use. According to the inspection plan or maintenance needs, DNV (DET NORSKE VERITAS (Det Norske Veritas) or CCS (China Classification Society) regulations require that cargo oil tanks need to be cleaned so that operators can enter the tank for maintenance or surveyors can enter the tank for internal structure , anti-corrosion coating and other aspects of the inspection. [0003] The tank washing operation is generally carried out at the same time as production, and according to relevant regulations, oil lifting operations cannot be carried out du...

AI Technical Summary

Problems solved by technology

[0005] 1. Poor effect and large amount of sewage: after crude oil tank washing, a large amount of crude oil is often attached to the bulkhead. Due to the poor compatibility between hot sea water and oil dirt, it is difficult for hot sea water to wash crude oil off the cargo oil bulkhead; large water consumption, Additional oily sewage is generated, which increases environmental protection costs; additional heating of tank washing water is required, which consumes a lot of energy; tank washing and stripping take a long time, which increases operational risks and personnel costs;

[0006] 2. It takes a long time for the purging gas to reach the standard, and the time left for the inspection and maintenance of the cabin is relatively short, which increases the risk of production suppression and production stoppage while cleaning the tank during production;

[0008] 4. Potential safety hazards: When using seawater to wash tanks for cooling, dissolved oxygen in seawater also enters oil-gas chambers, and local enrichment may cause deflagration due to static electricity; it is also difficult to clean up the imported seawater when stripping the tank, and the remaining seawater Accelerated the corrosion rate of the cargo oil tank and the equipment in the tank; after the crude oil tank is washed, the crude oil attached to the tank will continue to evaporate and produce hydrocarbon vapor, causing certain damage to the health and safety of the workers in the tank

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