**1. Statement of the problem**

The trunk pipelines for transporting liquid and gaseous hydrocarbons are one of the main types of transport infrastructure in the world.

The most important pumped media are crude oil, gas, broad hydrocarbon fractions, and petroleum products. The total length of trunk pipelines in the world is more than 1.5 million km; in Russia it is about 230 thousand km, and the length of oil pipelines in the world is 170 thousand km; in Russia it is about 70 thousand km.

The length of the largest individual oil pipeline systems is Canada-USA 4700– 5300 km with pipe diameters of 450–1220 mm, China-Kazakhstan 2200 km with a diameter of 813 mm, Azerbaijan-Georgia-Turkey 1768 km with a diameter of 1067 mm, Tanzania-Zambia 17,210 km with a diameter of 200–300 mm, and Italy-Germany 1000 km with a diameter of 660 mm.

In Russia, the largest oil pipelines are the Eastern Siberia-Pacific Ocean, 4740 km with a diameter of 1020–1200 mm, and Druzhba, 5500 km with a diameter of 520–1020 mm; eight trunk oil pipelines have a length of more than 1000 km.

computational schemes and computational cases and the assessment of static

*Combined Calculated, Experimental and Determinated and Probable Justifications…*

The basic strength condition was then recorded in the simplest form:

where is maximum operating voltage stress and is hazardous stress. For a thin-walled pipe with a diameter *D* with wall thickness , ring

ð1Þ

ð2Þ

strength, taking into account the types of stress and limit states.

*DOI: http://dx.doi.org/10.5772/intechopen.89036*

where is maximum operating pressure (**Figure 3**).

stresses are maximal: (**Figure 3**).

**Figure 2.**

**Figure 3.**

**145**

*The main design scheme.*

*Accidents on oil pipelines (Venezuela, China, Russia).*

**Figure 1.** *Oil trunk pipelines (Russia).*

The operating pressures in the main oil pipelines range from 2 to 10 MPa (**Figure 1**).

The trunk oil pipelines are operated in a very wide range of climatic conditions (from 70°С to +60°С) and natural hazards (seismic, landslides, geological faults), with ground, underground, and underwater laying.

Despite the large, more than century-old experience of research, testing, construction, and operation of oil trunk pipelines in the world and in Russia, there were large-scale accidents and disasters. These accidents were accompanied by the release of large amounts of oil (up to 100–600 thousand barrels) into the environment (land, water) with great environmental damage, fires, death and injury to people, and pollution of hundreds of hectares of land. Economic damages from such accidents are estimated at \$ 10–100 million. The total number of accidents on oil pipelines in the world over the past 20 years is more than 2000, and the number of large oil leaks is more than 4500. For every million tons of pumped oil, 3–5 tons fall into leaks.

In general, the accident rate on the trunk oil pipelines is reduced. However, at present it is at the level of 0.1–0.3 per 1000 km per year (**Figure 2**).

These data indicate the need for further research and practical development to reduce accidents and improve the safety of trunk pipelines.

In recent years, four basic approaches to determining the strength, resource, and safety of oil pipelines have emerged:

