Connection of Tanker and Wharf by Heart

date：2017-06-25 00:00:00 author：admin click1：35

A dispatcher on board is bridge and link connecting the two sides of ship and shore. Seven dispatchers on board from Shihua Company are only 28 years old averagely, with bachelor degree, CET 6 or above, as well as the foundation of Japanese, French, Spanish and other minority languages, and also they have received the professional training on senior captain of 300,000t-level tanker.

“The ship dispatchers of Rizhao Shihua have become a flag of Shihua Companies throughout the country, and they have made great contributions to reduction in demurrage charges and tank losses with excellent professional skills and dedicated spirits.” said by head of Sinopec Qingdao  Refining & Chemical.

Nothing is trivial in the interests of customers. In the crude oil handling process, the ship dispatchers, starting from the actual conditions of their positions, have strengthened the perspectiveness and controllability of work, and protected the interests of customers from different aspects. The “method of residual dischare during the close tank cleaning period” put forward by these dispatchers have been widely applied in actual production, through which, each tanker can have additional more than 4.8m³ crude oil unloaded. In terms of demurrage charges, over RMB 3million was saved for 8 tankers like “Xinpingyang Ship”, “Kali’ao Ship” and “Freedom Ship” only in 2015. In terms of tank losses, through inspection of pipelines on the tank bottom, more than 190m³ crude oil has been found out for the customers.

To make up the shortage of knowledge in tanker structure, ship unloading technology, equipment operation, physical and chemical properties of oil, the dispatchers have never missed any chance of learning. Apart from active participation in all training of technology and foreign language organized by Shihua Company, they have taken the initiative to learn professional knowledge from the captains and chief officers from all over the world. At work, they have established the system of “One Summarization for One Ship”, and solved through concentrative discussion the different problems one by one, including the unloading methods, valves and instruments, and equipment principles they are unfamiliar with.

At the beginning of this year, “Kaitai Ship” loaded with 136,000t of Basra crude oil moored in 6# berth, and this was the first time for Shihua Company to handle such kind of oil. According to the data provided by the shipper, Basra crude oil would be subject to step-wise double-tank unloading method in the handling process. After completion of unloading, more than 800 tons of tank losses were discovered through net oil depot measurement. After inspection for times, no residual oil was discovered in the oil depot, pipeline, and pump house of shipper.

Then, where did the crude oil go? These serious dispatchers obtained the test data from Sinopec library: API29.85, water content 7‰, density 0.873, temperature 30.3, and coefficient of viscosity 89.

The water content is higher, and viscosity is seriously higher. Dispatcher Liang Junfeng found the Basra crude oil tank washing code A1 from overseas websites, and dispatcher Zhang Tao found the information from IMO tank washing specification that the crude oil with a high water content is not suitable to crude oil tank washing.

When Basra crude oil was handled by Shihua Company for the second time, director of Sinopec Rizhao depot personally went to supervise the oil unloading on board, and required tank washing medium heating and total tank washing. The dispatchers, according to their previous studies, advised to only conduct bottom washing for 4 tanks, carry out crude oil switching of slop tank for every two tanks, and give up heating, so as to avoid the generation of crude oil stratification. Finally, through calculation, about 200m³ tank losses were caused this time, in the acceptable range of depot.

Afterwards, the dispatchers continued to optimize the oil unloading process, reducing the tanks needing washing to two ones, changing the double-tank closed washing into single-tank open unloading, closing the deck-mounted washing machine, and only using the bottom washing machine, and also adjusting the angle of washing machine to 30°. When Shihua Company handled a Basra crude oil ship for the third time, the tank losses of such oil reached the level of general oil.

Currently, there are rare papers, books, and provisions on 300,000t-level tanker handling at home. To learn advanced handling technology, they had to rely on the related data at abroad. “Integrated step-wise double-tank unloading method” frequently used in the crude oil handling process of Shihua Company was developed by the dispatchers on the basis of international general step-wise unloading method, in combination with many conventions and specifications, and according to the actual conditions of oil wharf and Sinopec tank field. “This method doesn’t have an ideal experiment effect on the crude oil with high sulfur, water, wax, coagulation, and viscosity, and aiming at the handling method of special oil, we plan to establish a research team, to solve different problems we are encountered with in the oil handling process one by one.” Dispatcher Zhao Tao told to the author.

Up to now, the dispatchers have participated in more than 540 ship-times of oil handling, and summarized many different methods including “horizontal wiping through manual control of deck-mounted washing machine angle”, effective oil collection through hull inclination by 0.5°”, “scavenging pump low-speed closed water shearing”, “residual discharge in the closed tank washing period”, and etc., and preliminarily developed the oil unloading process with characteristics of Rizhao Shihua Company.