FORM-2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE
Specification
(See Section 10 and Rule 13)
A METHOD OF PIPELINE TRANSPORTATION
HINDUSTAN PETROLEUM CORPORATION LTD.
an Indian Company,
of "Petroleum House", 17, Jamshedji Tata Road,
Mumbai - 400 020, Maharashtra, India
THE FOLLOWING SPECIFICATION PARTICULARLY PESCRIBES THE NATURE OF
THE INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED

FIELD OF THE DISCLOSURE
The present disclosure relates to a method for simultaneously transporting two or more fluids in a pipeline.
BACKGROUND
Transportation of fluids, particularly crude petroleum and refined petroleum products, is widely carried out through pipelines. Transporting crude petroleum and refined petroleum products through pipelines provides a cost effective and environment friendly solution over the traditional method of transporting the same through oil tankers. Further, transportation of crude petroleum and refined petroleum products via pipeline is less time consuming and reduces pilferage of petroleum products.
Batches of different petroleum products are transported over a distance through a common pipeline. These products are injected sequentially in the pipeline and pumped, one abutting the other, during the pipeline transfer. At each interface between the different batches, an intermixing zone is formed. This intermixing zone does not meet specification of any of the fuels. Hence the intermixing zone is kept below 1.0% of the total batch conveyed through the pipeline. On reaching the destination, the different batches of the petroleum products and the intermixing zone are separated. The fluid in the intermixing zone is required to be further treated, distilled or reprocessed. This phenomenon results in an increased processing cost of the refined petroleum product. Therefore, it is of great importance to reduce the volumes of fluid in the intermixing zone and thus minimize reprocessing thereof. The volume of the fluid in the intermixing zone can be reduced by:
• avoiding pipeline surges by preventing pumping shutdowns,
• making the batches as large volume as possible,
• ascertaining that two adjacent batches do not have substantially different densities; and
• grouping together batches having similar properties so as to minimize the reprocessing operations.

However, the most preferred method is to provide a buffer material that separates two consecutive refinery product batches. The buffer is typically a refinery product which is injected at each interface to minimize intermixing of the batches. The buffer is selected such that at the delivery point, the intermixing zone allotted to one of the refined petroleum product is substantially minimized resulting in reduction in reprocessing time.
Presently, kerosene is used as a buffer between gasoline (Petrol or Motor Spirit), gasoil (High Speed Diesel /Diesel /) and kerosene oil (SKO). The main drawback of using kerosene as a buffer is that it adversely affects the specifications of gasoline and gasoil in terms of sulphur content, flash point, Research Octane Number (RON), and kinematic viscosity. Thus, use of kerosene as a buffer results in significant reduction in quality of gasoil and gasoline at the starting point leading to increase in production cost.
Thus, there was felt a need to provide a method of pipeline transportation of refined refinery products which will not affect the specifications of the refinery products and without the need for reprocessing or treatment of the product thereof.
OBJECTS
Some of the objects of the system of the present disclosure, which at least one embodiment herein satisfies, are as follows:
An object of the present disclosure is to provide a method for pipeline transportation of refinery products which minimizes the reprocessing time at a receiving terminal.
Another object of the present disclosure is to provide a method for pipeline transportation of refinery products which minimizes the reprocessing cost at the receiving terminal.
Yet another object of the present disclosure is to maintain the intermixing region between two adjacent refinery products to the minimum.

Still another object of the present disclosure is to provide a method for pipeline transportation of refinery products wherein the intermixing region between adjacent fluids is absorbed in one or both of the fluids at the receiving terminal without affecting the quality of fluids.
Other objects and advantages of the present disclosure will be more apparent from the following description when read in conjunction with the accompanying figures, which are not intended to limit the scope of the present disclosure.
SUMMARY
In accordance with the present disclosure there is provided a method of pipeline transportation of a plurality refinery products, having varying properties, from a delivery terminal to a receiving terminal via a pipeline, the method comprising the following steps:
a. pumping alternate measured batches of refinery products and a plugging fluid
in the pipeline;
b. resulting in formation of an intermixed fluid in mixing zones between each of
the measured batches of the products and the plugging fluid;
c. sequentially conveying each of the measured batches of the refinery products
separated by the plugging fluid from the delivery terminal to the receiving
terminal;
d. segregating each of the refinery products and the plugging fluid at the
receiving terminal; and
e. selectively absorbing the intermixed fluid in one of the adjacent refinery
products contained therein.
Typically, the refinery products are selected from the group consisting at least one of gasoline, motor spirit, superior kerosene oil and high speed diesel oil.
Typically, the plugging fluid is selected from the group consisting at least one of heavy naphtha and light naphtha.

Typically, the relative volume of the plugging fluid is such that the adjacent refinery products are restricted from being intermixed on reaching the receiving terminal.
BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS
The method of pipeline transportation of fluids of the present disclosure will now be described with the help of accompanying drawings, in which:
Figure 1 illustrates a prior art pipeline transfer of different fluids separated by kerosene plug; and
Figure 2 illustrates a pipeline transfer of different fuels separated by the heavy naphtha plug, in accordance with the present invention.
DETAILED DESCRIPTION
Figure 1 represents a typical pipeline transportation of superior kerosene oil (SKO), gasoline grade 3 (E3 MS), gasoline grade 4 (E4 MS), gasoil grade 3 (E3 HSD) and gasoil grade 4 (E4 HSD), separated by kerosene plugs 10. A kerosene-gasoline interface 12 and a kerosene-gasoil interface 14 is generated, as shown in Figure 1, which can be allotted to gasoline and/or gasoil at the delivery point. However, use of kerosene plug significantly reduces the quality of gasoil and gasoline at starting point leading to increase in production cost.
A method of the present disclosure will now be described with reference to the embodiments which do not limit the scope and ambit of the disclosure.
The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to

practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
The present disclosure envisages a method for transporting a plurality of fluid batches, particularly refined products of petroleum, hereinafter referred to as condensate batches, in a pipeline between a delivery terminal and a receiving terminal. Each of the condensate batches has distinct properties/specifications. The plurality of condensate batches includes gasoline, superior kerosene oil (SKO) and gasoil. In order to prevent mixing of the condensate batches, a plugging fluid is provided between the condensate batches. The plugging fluid effectively separates the different condensate batches so as to prevent mixing of the condensate batches. The plugging fluid, typically heavy naphtha (SCN), hereinafter referred to as heavy naphtha plug, is obtained by distillation of crude oil, particularly low sulphur crude oil, at 65-170 °C.
As illustrated in Figure 2, a batch of heavy naphtha plug 100 is bracketed by two condensate batches 10. Each condensate batch 102 is considered as a head condensate batch or a tail condensate batch depending on whether the condensate batch is located downstream or upstream with respect to an adjacent heavy naphtha plug 100. The condensate batches 102 and the heavy naphtha plug 100 are alternately pumped in measured quantity within a pipeline such that a batch of heavy naphtha plug 100 is sandwiched between two condensate batches. Thus, a batch of heavy naphtha plug is in contact with a head condensate batch at one end and a tail condensate batch at the other. The condensate batches 102 and the heavy naphtha plug 100 are pumped into the pipeline at a predetermined temperature. Each measured condensate batch 102 is of a predetermined volume covering a predetermined length within the pipeline. Similarly, each measured batch of the heavy naphtha plug 100 has a predetermined volume and predetermined length.
At the interface of the heavy naphtha plug 100 with the head condensate batch and the tail condensate batch, two intermixing zone are formed at either ends of the heavy naphtha plug 100. The two intermixing zone includes a blend of condensate-plugging fluid having a portion of the head condensate batch diffused with the heavy naphtha

plug 100 and a portion of the tail condensate batch diffused with the heavy naphtha plug 100. Thus, two intermixing zones are formed in each batch of the heavy naphtha plug 100 and are separated by a portion of the heavy naphtha plug 100 which is not diffused with either the head condensate batch or the tail condensate batch. This prevents mixing of the head condensate batch and the tail condensate batch.
Table 1 provided below illustrates tabularized specifications/ properties of heavy naphtha as compared to gasoline.
Table 1
Parameters Heavy naphtha Gasoline (E4)
Density at I5°C(kg/m3) 778.9 720 - 775
Final Boiling Point (°C) 185 210 (max)
Octane Number 60±2 91 (mm)
Lead content (g/1) < 0.004 0.005 (max)
Table 2 provided below illustrates tabularized specifications/ properties of heavy naphtha as compared to gasoil.
Table 2

Parameters Heavy Naphtha High Speed Diesel (E3)
Density at 15 °C (kg/m3) 778.9 820 - 845
Total Sulfur (mg/kg) 87 350 (max)
Flash point (°C) <15 35 (min)
As is evident from the tables shown in Table 1 and Table 2, the properties/specifications of heavy naphtha do not substantially differ from that of the properties/specifications of gasoline and gasoil. For example, the density of gasoline at 15 °C is 720 - 775 kg/m3 and that of Gasoil, for example, High Speed Diesel, is 820 - 845 kg/m3 while the density of heavy naphtha at 15 °C is 778.9 kg/m3. Thus, the heavy naphtha plug 100 has properties/specifications such that when it is blended with gasoline and gasoil during transportation, the properties/specifications of the condensates are not substantially affected.
Alternate batches of condensates 102 and heavy naphtha plug 100 on arrival at the receiving terminal is sorted and stored in corresponding tanks. The blend of

condensate-plugging fluid formed at the interface of the tail condensate and the head condensate batch with a heavy naphtha plug 100 therebetween, has properties/specifications substantially similar to that of the head condensate batch and the tail condensate batch respectively. Hence, the blend of the condensate-plugging fluid is mixed in the tank containing the condensate corresponding to that contained in the blend of condensate-plugging fluid.
The heavy naphtha plug 100 eliminates mixing of the alternate batches of condensates 102 while restricting adverse effect on the properties/specifications of the various condensates such as sulphur content, octane number, flash point and viscosity. Hence, the heavy naphtha plug 100 diffused in a condensate within desirable limits can be stored in the corresponding condensate storing tank without degrading the quality of the condensate stored therein.
TRIAL DATA
Table 3 provided below illustrates a tabularized comparative analysis of the properties of heavy naphtha, gasoline and gasoil.
Table 3

Parameters Plug Gasoline grade 3 Gasoline grade 4 Gasoil
grade 3 Gasoil grade 4
Final Boiling Point (deg C) 185 210 max 210 max - -
Recovery Min @ 360 °C - - - 95% 95%
Octane Number 60 ±2 91 min 91 min - -
Total Sulfur (ppm) 87 150 max 50 max 350 max 50 max
Flash Point (°C) <15 - - 35 min 35 min
Table 4 provided below illustrates a tabularized comparative analysis showing the improvement in the specification of gasoil and gasoline with heavy naphtha plug against traditionally used kerosene plug.

Table 4

Parameters Gasoline Gasoline Gasoline Gasoline Gasoil Gasoil Gasoil Gasoil
grade 3 - grade 3 - grade 4 - grade 4 - grade 3 - grade 3 - grade 4 - grade 4
Kerosene heavy naphtha Kerosene heavy naphtha Kerosene heavy naphtha Kerosene - heavy
naphtha
Total 120 145 30 45 300 345 30 45
Sulfur
(ppm)
Final 190 205 190 205 - - . -
Boiling
Point (°C)
On comparing the blend of heavy naphtha with varying grades of gasoline and gasoil provided in Table 3 and Table 4 respectively, it is evident that the sulphur content and the boiling point of the various grades of gasoline and gasoil is not adversely affected by diffusion of the heavy naphtha plug during transportation. On the other hand, the sulphur content and the boiling point of the various grades of gasoline and gasoil mixed with kerosene, used as plugging fluid, during transportation is comparatively less desirable than those blend with heavy naphtha.
Table 5 illustrates tabularized data for heavy naphtha blend with gasoline in different proportion.
Table 5

Parameters Gasoline Heavy Gasoline Gasoline + Gasoline Gasoline + 4 %
Grade 4 naphtha +2% 4% heavy + 6% heavy naphtha +
heavy naphtha heavy 0.5% kerosene
naphtha naphtha oil + 0.5% gasoil
Final 184 184 183 183.5 183 184
Boiling
Point (°C)
Octane 93.2 60 ±2 92.7 92.2 91.6 91.8
Number
Total Sulfur 24 87 32 33 35 36
(ppm)
It is observed from Table 5 that heavy naphtha does not adversely affect the properties of gasoline. The final boiling point of the heavy naphtha admixed gasoline is improved, the octane number is reduced within limits, and the sulphur content is slightly increased. Also, even with the absorption of 0.5% kerosene oil and 0.5 % gasoil, the quality of gasoline is well within the desired specifications.

Table 6 provided in the below illustrates tabularized data for heavy naphtha blend with gasoil in different proportion.
Table 6

Parameters Gasoil Grade 4 Gasoil Grade 3 Heavy naphtha Gasoil Grade 3 + 1% heavy naphtha Gasoil Grade 3 + 2% heavy naphtha Gasoil Grade 3 + 4% heavy naphtha Gasoil
Grade 4 + 2% heavy naphtha Gasoil Grade 4 + 4% heavy naphtha
Viscosity @ 40 °C 2.59 2.60 - 2.55 2.47 2.35 2.46 2.32
Flash Point (X) 45 43 <15 41 40 37 41 37.5
Total Sulfur
(ppm) 43 203 87 201 198 192 46 48
It is observed from Table 6 that addition of heavy naphtha in gasoil results in a slight fall in the flash point, however, the specification remains well within the desired limits.
Table 7 provided below illustrates tabularized data for heavy naphtha (SCN) and kerosene oil (SKO) blend in gasoline in the proportion of 1:1.
Table 7

Parameters Gasoline Kerosene Heavy 1:1 1:1 1:1 1:1
Grade 3 oil naphtha SKO: SKO: SKO: SKO:
heavy heavy heavy heavy
naphtha naphtha naphtha naphtha
1% 2% 3% 4%
Final 181 252 184 184 188 190 194
Boiling
Point (°C)
Octane 93.4 - 60 ±2 92.8 91.8 90.6 89.8
Number
Total 29 620 87 34 39 43 47
Sulfur
(ppm)
Table 8 provided below illustrates tabularized data for heavy naphtha (SCN) and kerosene oil (SKO) blend in gasoline in the proportion of 2:1.

Table 8

Parameters Gasolin Kerosene Heavy 2:1 2:1 2:1 2:1
e Grade oil naphtha SKO: SKO: SKO: SKO:
3 heavy heavy heavy heavy
naphtha naphtha naphtha naphtha
1% 2% 3% 4%
Final Boiling 181 252 184 185 188 193 200
Point (°C)
Octane 93.4 - 60 ±2 92.4 91.2 89.8 88.5
"Number
Total Sulfur 29 620 87 36 41 47 54
(ppm)
Table 9 provided below illustrates tabularized data for flash point of and varying percentage blend of heavy naphtha and kerosene.
Table 9

Parameters SCN SKO 1%SCN 2% SCN 3% SCN
Flash Point (°C) <15 41 39.5 38 34
From the above results it is observed that heavy naphtha (SCN) can be used as a suitable plug for gasoline, gasoil and kerosene oil. Heavy naphtha (SCN) does not adversely affect the specifications of gasoline, gasoil or kerosene oil when mixed within limits.
TECHNICAL ADVANCEMENTS
The technical advancements offered by the present disclosure include the realization
of:
• a plugging fluid which does not adversely affect the octane number and sulphur content and flash point of condensates such as gasoil and gasoline;
• providing a simple and efficient plugging fluid between different fuels flowing in a pipeline which effectively separates the condensates and eliminates mixing of the adjacent condensates to a substantial degree; and

• a method of providing a plugging fluid that is conveniently absorbed in one or both of the condensates at the receiving terminal.
Throughout this specification the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.
The use of the expression "at least" or "at least one" suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the disclosure to achieve one or more of the desired objects or results.
The numerical values given of various physical parameters, dimensions and quantities are only approximate values and it is envisaged that the values higher or lower than the numerical value assigned to the physical parameters, dimensions and quantities fall within the scope of the disclosure unless there is a statement in the specification to the contrary. Wherever a range of values is specified, a value up to 10% below and above the lowest and highest numerical value respectively, of the specified range, is included in the scope of the disclosure.
The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.

We claim:
1. A method of pipeline transportation of a plurality refinery products, having
varying properties, from a delivery terminal to a receiving terminal via a pipeline,
said method comprising the following steps:
a. pumping alternate measured batches of the products and a plugging fluid in the
pipeline;
b. resulting in formation of intermixed fluids in mixing zones between each of
said measured batches of the products and said plugging fluid;
c. sequentially conveying each of said measured batches of the products
separated by said plugging fluid from the delivery terminal to the receiving
terminal;
d. segregating each of the products and said plugging fluid at the receiving
terminal; and
e. selectively absorbing said intermixed fluid in one of the adjacent products
contained therein.
2. The method as claimed in claim 1, wherein the product is selected from the group consisting at least one of gasoline, motor spirit, superior kerosene oil and high speed diesel oil.
3. The method as claimed in claim 1, wherein said plugging fluid is selected from the group consisting at least one of heavy naphtha and light naphtha.
4. The method as claimed in claim 1, wherein the relative volume of the plugging fluid is such that the adjacent refinery products are restricted from being intermixed on reaching the receiving terminal,