Design and economical evaluation of a crude oil transport pipeline
A crude-oil pipeline system of 400 km length is to be designed. The design flow rate is 198000 bbl/day. The specific gravity and kinematic viscosity of the crude-oil at the design temperature of 4°C is 0.8701 and 37 c5t, respectively. A terminal pressure head of 50 m is to be maintained. The maximum allowable operating pressure for the pipeline (MAOP) is set to be 90 bars. The selected pipe material is API grade SL-X60. The pipeline profile is given in the following table:
|
Distance (km)
|
Elevation (m)
|
|
0
|
40
|
|
30
|
75
|
|
75
|
400
|
|
150
|
250
|
|
180
|
360
|
|
250
|
250
|
|
325
|
450
|
|
360
|
120
|
|
400
|
100
|
The project should focus on the fundamentals of pipeline design as emphasized throughout the course. It should provide a general overview of the system approach of design, which integrates the hydraulic and mechanical components of pipeline design, along with project economic analysis, in determining the preferred pipeline system.
The project should also include discussion of design topics for related pipeline-system components such as the pump station location and sizing, hydrostatic testing for pipelines and analysis and control of fluid transients.
The project consists of four main parts:
Hydraulic design
The hydraulic design is the process of evaluating the physical properties of the crude oil to be transported, the quantities to be transported, the pipeline route and topography, and the range of pressures, temperatures, and environmental conditions along the route. Identifying the number and location of pump stations with respect to the hydraulic characteristics of the system is also part of the hydraulic design.
This part also includes the selection of the suitable pipe diameter using the appropriate codes and standards.
Mechanical Design
The mechanical design is governed by the codes and standards, developed through operating petroleum pipeline systems, and focuses on selection of pipe wall thickness as required by the stresses imposed on the system by the hydraulic and thermal conditions as well as external loading. ASME B31.4 code should be implemented in the project.
Pipeline Economics
In this part, the cost of a pipeline and the various components that contribute to the economics of pipelines are studied. These include the major components of the initial capital costs and the recurring annual costs. The project should also establish the transportation charge based on throughput rates, project life, interest rate, and financing scenarios.
Fluid transients in the pipeline
The generation of fluid transients in piping systems is an entirely normal process and will occur in all fluid systems subject to changes in flow conditions. The study of such transients Is of great practical importance and may well provide the design condition for the fluid system as a whole. The project should study the generation of fluid transients in the pipeline and, using suitable surge control devices, should ensure safe operation of the pipe under transient conditions.