Standard Oil Survey for $25,000

Best Binary Options Brokers 2020:
  • Binarium
    Binarium

    The Best Binary Options Broker 2020!
    Perfect For Beginners!
    Free Demo Account!
    Free Trading Education!

  • Binomo
    Binomo

    Good choice for experienced traders!

Here Is All You Wanted to Know About Draft Survey Calculations

Have you seen a truck weighing bridge ? Do you know how it works ?

It weighs the empty weight of the truck and then the loaded weight. The difference is the weight of the cargo on that truck.

Well draft survey uses a similar principle to measure the cargo loaded on board ships.

With draft survey we measures the initial weight (displacement) of the ship and it measures the final weight (displacement) of the ship after loading. The difference plus all the weights that were taken out (like ballast) will be the cargo loaded.

The only difference between weight measurement in case of truck and ship is that for later the calculation is not that simple.

So in this post I will discuss about how to go about measuring the cargo quantity with draft survey.

1. Why Draft survey ?

On tankers, the measurement of cargo quantity loaded is simple. We know the density of the cargo and we know the volume. It is easier to know the weight of the cargo loaded.

But with cargoes like coal, we cannot measure the weight by just measuring the the height of the hold to which cargo is loaded.

This is because unlike liquids, solid cargoes would not take the shape of the hold.

Calculating the cargo loaded with draft survey is the most appropriate way.

Best Binary Options Brokers 2020:
  • Binarium
    Binarium

    The Best Binary Options Broker 2020!
    Perfect For Beginners!
    Free Demo Account!
    Free Trading Education!

  • Binomo
    Binomo

    Good choice for experienced traders!

But it isn’t only with solid cargoes. Sometimes we have to measure the cargo quantity of liquids by draft survey. One such cargo is Mollasses loaded on chemical tankers.

This cargo has air in it and thus the density of this cargo is not uniform. Calculating the way we calculate the weights for other liquids will give wrong quantity. Draft survey is the answer in this case too.

So let us see how we need to go about draft survey.

2. Basics of Draft survey

With draft survey calculations, all we want to know is the difference in ship’s arrival weight (Displacement) and departure weight (displacement).

Let us say we have these figures

On Arrival

Displacement: 20000 T

Other weights : 1000 T

On Departure

Displacement: 50000 T

Other weights : 1000 T

The difference in displacement is 30000 T. Out of this 5500 T of ballast was removed and some cargo was loaded at the port.

It is simple calculation to know the quantity of the cargo loaded which is 35500 T.

In this simple calculation, it is not difficult to know the ballast and fuel on board. What we need to know is the displacement of the ship on arrival and after completion of loading.

Once we know that, we can know the cargo quantity. The easiest way to calculate the ship’s displacement is by noting down the draft of the vessel and looking for the displacement for that draft in the trim and stability booklet.

That is the simplest way of saying it but then there are few corrections to this which we will discuss.

3. Draft of the vessel

There are two drafts for a vessel.

  • Draft at forward and aft perpendiculars and at midship of these two. This is the draft that is listed in the ship’s trim and stability booklet.
  • Drafts at actual draft marks painted on ship side.

So to get the displacement from the trim and stability booklet, we must get the drafts at the perpendiculars.

What we will get from the visual drafts will not be the drafts at perpendiculars in most of the cases.

Let us say we have the visual draft as follows. In draft survey calculation we call the visual drafts as “Apparent drafts”.

So let us say that the mean of both side of the apparent drafts is

Apparent Trim = 2.1 m

As I said we need to bring these drafts to the perpendiculars.

The formula for correction to the visuals drafts to bring it to the perpendiculars is

You will find this distances in the Trim and stability book of the ship. Have a look at these corrections for one of the ship.

As we can see that the distance from forward perpendicular to the forward draft mark is 9.95 meters.

So the correction to the forward draft would be 9.95 x 2.10 / 155. This will be equal to 0.135 meters. As the forward perpendiculr is forward of the draft marks and we have stern trim, this correction will be negative.

Same way for apparent trim of 2.10 meters, the corrections to the apparent drafts are

So the drafts at forward and aft perpendiculars and midship will be 6.295 m / 8.653 m / 7.451 m respectively.

Ideally we should now take the midship draft (7.451 m in this case) and look for the displacement from the trim and stability booklet.

But there can be errors in this drafts and we have to make sure that draft is correct. These error could be

  • Errors in reading few of the visual drafts
  • Errors due to Hog or Sag of the vessel

To minimise these errors we finalise the draft of the vessel by having mean of means draft. This is also called Quarter mean draft.

Mean of means is considered to be the accurate draft of the vessel at the midship. This is the draft we need to enter in the trim and stability booklet.

Below is the mean of means draft for our example.

4. Calculating displacement of the ship

Now that we know the draft of the ship, we can open the trim and stability booklet and check the displacement for this draft.

We may have to interpolate to get the exact displacement.

Here is the relevant page of Trim and stability booklet for this ship.

So the displacement for our draft of 7.45675 m will be 30702.28.

We have now got the displacement for the actual draft of th vessel. But there will be few corrections to this displacement. Let us see what these are.

5. 1st Trim correction

The draft and displacement we got so far is at the mean of aft and forward perpendicular.

As per Archimedes principle, a floating ship displaces the amount of water equal to its own weight. And the ship floats at the center of floatation. So the correct displacement is the displacement corresponding to the draft at the center of floatation and not at the mean draft.

The correction applied to the displacement at mean draft to bring it to the displacement at center of floatation is called the “1st Trim correction”.

The formula for 1st trim correction is

If you wish to know how this formula arrived, watch this video

As we need the values of TPC and LCF for calculating 1st trim correction, open the Trim & stability booklet and find these values for the vessel’s draft. Again we have to do the interpolation to get the exact values.

Now let us calculate the 1st Trim correction for our example.

In this case it comes out to be 65 T but it can have larger value in other situations. This 1st trim correction we need to add to the displacement we got earlier.

Sign of 1st trim correction

This is not so difficult to find. We have the draft at the Midship and we are applying the correction for change in draft because LCF is not at the midship.

Now let us say vessel has stern trim and LCF is aft of midship. Which draft will be more ? The one read at the LCG or at the midship ?

You are right . The draft at the LCF will be more. So in this case the correction need to be added to the midship displacement we have got.

So for sign of 1st trim correction, all we have to see is the location of LCF with respect to Midship.

So for sign of 1st trim correction, all we have to see is the location of LCF with respect to Midship. Then by pure logic, we can find out if we need to add that correction or subtract.

6. 2nd Trim correction

Now there is this another correction. First trim correction was because LCF was not at the midship. If the LCF was at the midship, there would not be any 1st trim correction.

The distance of LCF from the midship is given in the trim and stability booklet. For hydrostatic ship particulars for some ships, the value of LCF is at zero trim condition. For example see below

Now if the vessel is trimmed, the position of LCF will change slightly because of change in water plane of the ship.

2nd Trim correction takes care of this change of position of LCF because of trim of the vessel.

The formula for 2nd trim correction is

To get the value of Dm-Dz, get the value of MCTC for (mean draft +50 cms) and for (mean draft-50 cms). The difference between these two values of MCTC will be the value for Dm-Dz.

With this value of Dm-Dz, we will get 2nd Trim correction as 35 T.

The 2nd trim correction is always positive.

But see the hydrosatic particulars of the vessel that I took the data from. LCF values are given for different trims.

We can interpolate to get the LCF for actual trim of the vessel. In this case 2nd trim correction will not be applicable.

7. Final Displacement

Once we have 1st trim correction and 2nd trim correction, we need to apply these to the ship’s displacement.

So the actual displacement with respect to the draft at LCF will be

Displacement at Midship + 1st Trim correction + 2nd Trim correction

In our example this would be 30702.28 + 65 +0 = 30802.28 T

8. Density correction

We have now got the displacement for quarter mean draft. To this displacement we have applied 1st trim correction and 2nd trim correction.

We now have vessel’s actual displacement. But this displacement is in salt water density of 1.025 as most of the hydrostatic tables have the data for that density.

Now if the water density around the vessel is different than 1.025, the displacement of the vessel will change.

Why ? As per archimedes principle the ship displaces water equal to its own weight. If the density of the water is more, ship would displace less volume of water (less draft). And if density of the water is lesser, it would need to displace more volume of water (more draft) to have same weight as of the ship itself.

For draft survey, we need to measure the density of dock water just before or after reading the visual drafts. The density is measured by draft survey hydrometer with a sample of dock water drawn from around the vessel.

The density of dock water changes with depth. So it is important to know at what depth the sample is drawn. Many take the sample from a depth that is half the draft of the vessel. Others prefer to take the sample by running the emergency fire pump.

Now say we have measured the density and we have the dock water density as 1.01

So how to correct the displacement we calculated so far for density ?

So in our example it will be 30802.28 x 1.01/1.025. That will be equal to 30351.51.

9. Cargo quantity from initial and final displacement

Apart from calculating the displacement, we need to to know the existing weights on vessel.

For example we need to know the exact weight of ballast, Fuel oil, Lube oil, fresh water etc on board on arrival. That is not a difficult thing to know. But there are some best practices.

First it is easier to measure the quantity if a tank is either completely full or completely empty. This also removes the ambiguity and measurement error.

Second, the vessel must not be down by head (negative trim). This is because it brings ambiguity to the actual quantity of ballast in a tank.

Third, since we need to know the weight of the ballast, we must know the density of the water in the ballast. We will know the volume from the sounding table and multiplying with the density will give the weight in each ballast tank.

Fourth, we need to measure and sound each space on ship and not assume that it is empty. For example if there is any void spaces, we must sound these spaces as well.

So now we will know what contributes to the the arrival displacement of the ship.

Arrival displacement = Lightweight of ship + Ballast + Fuel + Fresh water + Lube oil + Constants

And among these things we know the quantity of ballast, fuel, lube oil, and fresh water.

We need to repeat this calculation and measurement of all spaces after completion of loading.

Departure Displacement = Cargo + Lightweight of ship + Ballast + Fuel + Fresh water + Lube oil + Constants

Lightweight of the ship and constants will remain same and so these does not matter. We would know the arrival and departure displacement from draft survey. All other weights we know by sounding and measurement. The only known is the cargo loaded. It is simple mathematics then to know the cargo quantity.

10. Calculating constants on arrival

Calculating constants is not really required if our aim is only to know the weight of the cargo loaded. This is because the the quantity of constants will not change.

But calculating the constants on arrival is a good practice. This gives a fair idea of the correctness of calculation. For example, let us say we know that constants will be in the range of 200 to 300 tons.

If initial calculations give too high or too low constants, we know something is wrong somewhere.

We can sometimes get negative constants. This would mean that we have done some mistake and we must find it and correct it. It may be that we have wrong drafts, wrong soundings etc. Whatever it is, we must correct it before loading starts.

Conclusion

Draft survey is widely used for cargo measurement. It is acceptable way of measuring the cargo quantity.

The calculation however requires practice. It may sometimes be confusing to seafarers using the draft survey for the first time. This can lead to the errors in calculations and cargo claims.

We must know the basics of the draft survey. Once we know that draft survey would not look that difficult.

About Capt Rajeev Jassal

Capt. Rajeev Jassal has sailed for over 20 years mainly on crude oil, product and chemical tankers. He holds MBA in shipping & Logistics degree from London. He has done extensive research on quantitatively measuring Safety culture onboard and safety climate ashore which he believes is the most important element for safer shipping.

67 Comments

Sunil Bhatia

I just went thru your article on draft survey. Well depicted and explained. Good guide for people actually doing it specially Surveyor appointed to do so, as many a times they do not have perfect knowledge and may get carried away . thanks for sharing

Rajeev Jassal

Achiko Tevzadze

Gd day mr jassal. Its amazing blog. I just want to ask ,how you get this displacement 30702.28 ? My calculations is less. Many thanks

samuel T. Appleton

many thanks for your presentation its really help me in the area of draft survey.

The World’s Largest Oil Reserves By Country

Proven oil reserves are those that have a reasonable certainty of being recoverable under existing economic and political conditions, with existing technology.

Many oil-producing nations provide unaudited claims for their oil reserves.

The volatility in oil prices over the past decade has created plenty of concern for businesspeople, national governments, and global policymakers alike. With such uncertainty in pricing, coupled with environmental concerns as our world’s appetite for fossil fuels grows, the questions of whether there are enough petroleum oil reserves to satisfy demand, and what the consequences of its extraction will be, have never been more pertinent. In order to shed more light into a somewhat ambiguous subject, we have profiled the ten countries with the largest oil reserves in the world to help put their positions within the energy landscape into perspective. The volatility in oil prices over the past decade has created plenty of concern for governments and policymakers at the global stage. This lack of certainty, coupled with environmental concerns as the world grows ever more energy hungry, the question of whether there are enough petroleum oil reserves to satisfy the demand and what the consequences will be has never been more pertinent. In a bid to shed more light in this somewhat nebulous sector, we have profiled countries with the highest oil reserves in the world. These are the countries whose proven oil reserves are in the top 10 globally.

10. United States – 39,230 million barrels

The oil reserves of the United States (US) soared to new heights in recent years due to increased usage of unconventional drilling methods that enable extraction of more shale oil and gas than was previously possible. As a result of these, especially fracking and horizontal drilling, US reserves surpassed 36,000 million barrels in 2020 for the first time since 1975. Still, proven US oil reserves are but a fraction of the reserves of the global petroleum leaders such as Venezuela, Saudi Arabia, and Canada.

9. Libya – 48,363 million barrels

Libya has the largest oil reserves in Africa and the ninth largest globally. It has the potential to have a greater reserve of fossil fuel than we currently know of, as it remains largely unexplored as a result of past sanctions against foreign oil companies. Libyan oil accounted for 98% of government revenue in 2020 but, due to recent political instability, Libya’s power as an oil producer has been significantly hampered. Eventually, it is expected that untapped oil reserves will foster more economic investment as the political situation stabilizes.

8. Russia – 80,000 million barrels

Russia is a country filled with natural resources for energy use, most notably the country’s massive oil reserves under the vast Siberian plains. Russian oil output fell considerably after the collapse of the former Soviet Union, but the country has revamped production in the past few years. The nation may further boost its reserves of oil and gas in the future as exploration continues beneath its holdings of arctic waters and ice.

7. United Arab Emirates – 97,800 million barrels

The United Arab Emirates (UAE) sources most of its oil from the Zakum field, which has an estimated 66 million barrels, making it the third largest oil field in the region, behind only Ghawar Field (Saudi Arabia) and Burgan Field (Kuwait). Roughly 40% of the country’s GDP is based on oil and gas output and, since its discovery there in 1958, has enabled the UAE to become a modern state with a high standard of living.

6. Kuwait – 101,500 million barrels

While a small country in terms of land area, Kuwait holds more than a fair share of the world’s petroleum oil reserves. Over 5 bbl of reserves lies within the Saudi-Kuwaiti neutral zone which Kuwait shares with Saudi Arabia, while over 70 million barrels of Kuwaiti oil are in the Burgan field, the second largest oil field in the world.

5. Iraq – 142,503 million barrels

Despite shaky political situations in its recent history, the country of Iraq sits upon some of the world’s largest proven reserves of petroleum crude oil. As a matter of fact, owing to the civil unrest and military occupations which have characterized the national scene over the last few decades, it was not possible to do any meaningful exploration of Iraq’s oil reserves. As a result, even the data used to determine Iraq’s global oil holdings ranking is at least three decades old and based on 2D seismic surveys. Nevertheless, a period of relative calm over the last couple of years has given increased hope for developing the country’s oil infrastructure.

4. Iran – 158,400 million barrels

Iran has close to 160,000 million barrels of proven oil reserves, making it considerably wealthy in terms of global oil resources. When looking at the most easily accessible reserves (excluding many of the unconventional, difficult-to-extract reserves in Canada), Iran falls right behind Venezuela and the Kingdom of Saudi Arabia.

Oil in Iran was first produced in 1908 and, at its current rate of extraction, Iran’s oil will last close to 100 years more. Unlike Saudi oil, which is spread throughout a few huge and very rich oil fields, Iranian oil is found in close to 150 hydrocarbon fields, many of which have both petroleum crude oil and natural gas.

3. Canada – 169,709 million barrels

Canada has almost 170,000 million barrels of proven oil reserves, of which the most significant proportion is in the form of oil sands deposits in the province of Alberta. Furthermore, most of the country’s conventionally accessible oil reserves are located in Alberta.

As extracting oil from the vast majority of Canada’s oil reserves is a labor and capital-intensive process, production tends to come in sporadic bursts rather than steady streams. Oil companies, therefore, begin by extracting lower density, higher value oils first, and directing their efforts into extracting crude deposits only in times of high commodity prices.

2. Saudi Arabia – 266,455 million barrels

The Kingdom of Saudi Arabia has for many decades been viewed as the modern state most iconic of oils equation to opulence and influence in global politics. However, Saudi Arabia is no longer the world’s leader in oil potential.

While the Saudis’ 266,455 million barrels of proven oil reserves are marginally smaller than those of Venezuela, all of Saudi’s oil is in conventionally accessible oil wells within large oil fields. Moreover, Saudi Arabia’s reserves are considered to comprise a fifth of the entire globe’s conventional reserves. There are many who also believe that, with further exploration, Saudi Arabia will surpass Venezuela at the top of the proven oil holdings charts. For example, the US Geological Survey estimates that there are well over 100,000 million barrels lying undiscovered beneath the arid sands of Saudi deserts.

1. Venezuela – 300,878 million barrels

With 300,878 million barrels of proven reserves, Venezuela has the largest amount of proven oil reserves in the world. The country’s oil is a relatively new discovery. Previously, Saudi Arabia had always held the number one position.

The oil sand deposits in Venezuela are similar to those in Canada. Venezuela also boasts plenty of conventional oil deposits. Venezuela’s Orinoco tar sands are significantly less viscous than Canada’s, so the oil sands there can be extracted using conventional oil extraction methods, giving it a considerable advantage over the Northern American rival in terms of capital requirements and extractions costs.

Oil States International Inc (OIS)

Нью-Йорк

Тикер Биржа Валюта
OIS Нью-Йорк USD Реальное время
OIS Штутгарт EUR C задержкой
OIS Мюнхен EUR C задержкой
OIS Берлин EUR C задержкой
  • Чтобы воспользоваться этой функцией, войдите в свою учетную запись.
  • Убедитесь, что вы используете ту же учетную запись, что и на сайте.

Следить за отчетами компании Oil States

Все последующие выпуски Только предстоящий выпуск Получить напоминание за 1 торговый день

Позиция успешно добавлена:

  • Объем: 908.370
  • Спрос/Предл.: 0,00 / 0,00
  • Дн. диапазон: 2,15 – 2,45

Обзор OIS

  • 1 день
  • 1 неделя
  • 1 месяц
  • 3 месяца
  • 6 месяцев
  • 1 год
  • 5 лет
  • Макс.

Новости по Oil States International Inc

Investing.com — Представляем топ-5 новостей финансовых рынков в понедельник, 29 июля 2020 г. 1. Возобновление торговых переговоров между США и Китаем на фоне слабых.

Техническое резюме

Тип 5 мин 15 мин 1 час 1 день 1 месяц
Скол. средние Покупать Покупать Покупать Продавать Активно продавать
Тех. индикаторы Активно покупать Активно покупать Активно покупать Продавать Активно продавать
Резюме Активно покупать Активно покупать Активно покупать Продавать Активно продавать

Свечные модели

Модель Временной период Надежность Х свечей назад Время
Новые модели
Advance Block Bearish 5H Текущая
Завершенные модели
Three Outside Up 5H 1 06.04.2020 16:00
Bullish Engulfing 5H 2 03.04.2020 18:00
Engulfing Bearish 1M 3 Янв. ’20

Котировки Oil States International Inc

Биржа Цена Спрос Предл. Объем Изм. % Валюта Время
Нью-Йорк 2,29 0,00 0,00 908.370 +8,02% USD 06/04
Штутгарт 1,790 17,040 17,422 0 0,00% EUR 03/04
Мюнхен 2,08 2,12 2,16 0 +10,05% EUR 09:22:00
Берлин 2,06 2,10 2,20 0 +8,99% EUR 10:37:00

Трендовые акции

Позиция успешно добавлена:

  • Чтобы воспользоваться этой функцией, войдите в свою учетную запись.
  • Убедитесь, что вы используете ту же учетную запись, что и на сайте.

Все последующие выпуски Только предстоящий выпуск Получить напоминание за 1 торговый день

Название Послед. Макс. Мин. Изм. Изм.% Объём Время
Сбербанк 199,06 200,54 193,02 +8,36 +4,38% 72,33M 12:39:34
Газпром 194,13 195,13 192,09 +3,03 +1,59% 31,59M 12:39:38
Аэрофлот 76,40 76,70 74,16 +3,68 +5,06% 20,59M 12:39:41
Норильский никель 19.968,0 20.132,0 19.680,0 +378,0 +1,93% 156,18K 12:39:39
ЛУКОЙЛ 5.221,0 5.260,0 5.170,5 +58,0 +1,12% 670,41K 12:39:42
Роснефть 348,80 386,95 347,25 +5,80 +1,69% 10,02M 12:39:42
Банк ВТБ 0,0350 0,0352 0,0342 +0,0014 +4,07% 52,92B 12:39:34
Система 14,53 14,78 14,10 +0,58 +4,14% 53,26M 12:39:35
РУСАЛ 26,55 26,62 26,01 +0,80 +3,11% 13,06M 12:39:41
АК АЛРОСА 65,65 66,50 63,99 +2,15 +3,39% 17,71M 12:39:40

Сведения о компании Oil States International Inc

Начните торговать с ведущими брокерами

Брокеры Регулятор Мин. вклад
Нет $500 Торговать
Управление по финансовому регулированию и надзору (Сент-Винсент и Гренадины ) $1 Торговать
Нет $500 Торговать

Участвуйте в форуме для взаимодействия с пользователями, делитесь своим мнением и задавайте вопросы другим участникам или авторам. Пожалуйста, используйте стандартный письменный стиль и придерживайтесь наших правил.

  • Размещение ссылок, рекламы и спам;
  • Ненормативная лексика, а также замена букв символами;
  • Оскорбления в адрес участников форума и авторов;
  • Разжигание межнациональной и расовой розни;
  • Комментарии, состоящие из заглавных букв.
  • Допускаются комментарии только на русском языке.
Best Binary Options Brokers 2020:
  • Binarium
    Binarium

    The Best Binary Options Broker 2020!
    Perfect For Beginners!
    Free Demo Account!
    Free Trading Education!

  • Binomo
    Binomo

    Good choice for experienced traders!

Like this post? Please share to your friends:
How To Make Money on Binary Options Trading
Leave a Reply

;-) :| :x :twisted: :smile: :shock: :sad: :roll: :razz: :oops: :o :mrgreen: :lol: :idea: :grin: :evil: :cry: :cool: :arrow: :???: :?: :!: