Fuel factories and mines in Saudi Arabia, large and huge warehouses and tanks, towers and metal structures in desert lands, oil and gas refineries, petrochemical industries and projects, the concept of petroleum engineering in the Gulf countries, the renaissance of the Saudi national economy
Engineering and urban development of oil refineries in the Kingdom of Saudi Arabia, oil refinery on soft golden sands, harsh and dry climate, adoption of modern techniques and technology in oil and gas production, petrochemical industries and projects, huge and modern tools and equipment
Work in the field of petroleum engineering, oil and gas refinery, a group of Saudi Gulf Arab workers wearing a protective suit and a protective helmet repairing machinery and equipment in oil laboratories and factories in the Kingdom of Saudi Arabia, pipelines extending from the depths of the sea to refineries.
The field of petroleum engineering in the Gulf countries, oil and gas refineries, petrochemical projects contributing to the renaissance of the Saudi national economy, oil factories and laboratories in the Kingdom of Saudi Arabia, large and huge warehouses and tanks, the view of the sky at dusk with high illuminated structures
The concept of gas production in Saudi Arabia. Monitoring the workflow in factories, pipelines and steel cables. A close-up shot of a group of Saudi-Gulf engineers working in an oil and gas refining plant, working in the field of petrochemical industries and projects.
Fuel factories and mines in Saudi Arabia, large and huge warehouses and tanks, towers and metal structures in desert lands, oil and gas refineries, petrochemical industries and projects, the concept of petroleum engineering in the Gulf countries, the renaissance of the Saudi national economy
View of factory smoke spreading in the air, oil and gas refining plant, petrochemical industrial projects, economic growth and progress, oil production in the Kingdom of Saudi Arabia
Petroleum engineering concept in Gulf countries, lighting towers and structures at night, oil factories and plants in Saudi Arabia, petrochemical industries contributing to the renaissance of the Saudi national economy, huge warehouses and tanks, background of the sky covered with black clouds on a stormy night
Petrochemical industries and projects, pollution resulting from oil production, steel pipelines and cables, oil and gas refinery in the industrial area, factories and plants in the Kingdom of Saudi Arabia, large and huge warehouses, industrial engineering and equipment
The concept of work in the industrial engineering sector, the quality of machines and equipment in oil extraction laboratories, modern techniques in oil and gas production, oil refining plants at sunset in the Kingdom of Saudi Arabia.
The concept of gas production in the Kingdom of Saudi Arabia, following up on the progress of work in factories, a close-up photo of two Saudi Gulf Arab engineers wearing helmets and a protective vest and standing between pipelines, Saudi engineering professions and jobs, oil refining factory background
Petrochemical industries and projects, the concept of petroleum engineering in the Gulf countries, the gas refinery, the renaissance of the Saudi national economy, the view of large and huge warehouses and tanks at sunset, oil factories and laboratories in the Kingdom of Saudi Arabia
Quality of machinery and equipment in oil extraction plants, oil refineries at sunset in Saudi Arabia, concept of work in the industrial engineering sector, modern technologies in oil and gas production
Gas refinery, lighting towers and metal structures, sky full of clouds, oil factories and plants in Saudi Arabia, petroleum engineering concept in the Gulf countries, petrochemical industries and projects, large and huge warehouses and tanks
Follow up and monitor the progress of work in factories, the concept of gas productivity in the Kingdom of Saudi Arabia, Saudi engineering professions and jobs, a picture from the back of two Saudi Gulf Arab engineers wearing helmets and protection vests walking in the oil refining factory
Industrial engineering and equipment, factories and laboratories in the Kingdom of Saudi Arabia, oil and gas refining plant, Dukhan refinery laboratories, petrochemical industries and projects, huge and large warehouses, white background
Oil refinery in the desert of Saudi Arabia, huge and modern tools and equipment, adoption of modern techniques and technology in oil and gas production, soft golden sand dunes, engineering and urban development of oil refineries
Engineering development of oil refineries in Saudi Arabia, oil mines on soft golden sands, harsh and dry climate, adoption of modern technologies in oil and gas production, petrochemical industries and projects, huge and modern tools and equipment, towers and metal structures in desert lands
Factories and plants in Saudi Arabia at sunset, industrial engineering and equipment, petrochemical industries and projects, economic growth and progress, refinery smoke factories, oil and gas refining plant, huge and large warehouses, view of factory smoke in the air, oil production in the Kingdom
Petroleum engineering concept in the Gulf countries, oil factories and plants in the Kingdom of Saudi Arabia, petrochemical projects contributing to the renaissance of the Saudi national economy, oil and gas refinery, large and huge warehouses and tanks, cloudy sky background at sunset
Petrochemical industries and projects, pollution resulting from oil production, steel pipelines and cables, oil and gas refinery in the industrial area, factories and plants in the Kingdom of Saudi Arabia, large and huge warehouses, industrial engineering and equipment
Oil and gas refinery, petrochemical projects contributing to the renaissance of the Saudi national economy, oil factories and plants in Saudi Arabia, lighting towers and metal structures at night, pollution resulting from oil production
Monitoring the progress of work in factories and plants, a close-up image of a Saudi Arabian Gulf engineer holding a laptop in his hand working in an oil and gas refining plant, working in the field of petrochemical industries and projects, the concept of gas productivity in the Kingdom of Saudi Arabia, steel pipelines and cables
Oil refinery on soft golden sands, engineering and urban development of oil refineries in the Kingdom of Saudi Arabia, harsh and dry climate, adoption of modern techniques and technology in oil and gas production, petrochemical industries and projects, huge and modern tools and equipment
Oil and gas refineries, petrochemical industries and projects, the concept of petroleum engineering in the Gulf countries, the renaissance of the Saudi national economy, towers and metal structures in desert lands, large and huge warehouses and tanks, fuel factories and plants in the Kingdom of Saudi Arabia
Fuel factories and mines in Saudi Arabia, large and huge warehouses and tanks, towers and metal structures in desert lands, oil and gas refineries, petrochemical industries and projects, the concept of petroleum engineering in the Gulf countries, the renaissance of the Saudi national economy
The concept of petroleum engineering in the Gulf countries, petrochemical industries and projects, gas refinery, the renaissance of the Saudi national economy, the view of large and huge warehouses and tanks, oil factories and laboratories in the Kingdom of Saudi Arabia
Saudi professions and jobs, a picture from the back of two Saudi Gulf Arab engineers wearing helmets and protection vests walking in an oil refinery factory, the concept of gas production in the Kingdom of Saudi Arabia, following up on the progress of work in factories, blue sky background
Follow up the progress of work in factories and plants, a group of Saudi Arabian Gulf engineers working in an oil and gas refining plant, working in the field of petrochemical industries and projects, steel pipelines and cables, the concept of gas productivity in the Kingdom of Saudi Arabia
Oil and gas refineries, petrochemical industries and projects, petroleum engineering concept, renaissance of the Saudi national economy, metal structures in desert lands, large and huge warehouses and tanks, fuel factories and mines in the Kingdom of Saudi Arabia
Engineering and urban development of oil refineries in the Kingdom of Saudi Arabia, oil refinery on soft golden sands, harsh and dry climate, adoption of modern techniques and technology in oil and gas production, petrochemical industries and projects, huge and modern tools and equipment
Petrochemical industries and projects in the Kingdom, Extraction of underground resources from the sea, Huge machines and heavy equipment used in oil exploration, Work in the field of petroleum engineering, Oil and gas refining plants in the industrial zone in Saudi Arabia, Saudi economic growth and progress
Steel pipelines and cables, monitoring the progress of work in factories and plants, close-up from the back of a Saudi Arabian Gulf engineer working in an oil and gas refinery, working in the field of petrochemical industries and projects, the concept of gas productivity in the Kingdom of Saudi Arabia
Large and massive warehouses and tanks, towers and metal structures in desert lands, oil and gas refineries, petrochemical industries and projects, the concept of petroleum engineering in the Gulf countries, the renaissance of the Saudi national economy, fuel factories and mines in the Kingdom of Saudi Arabia
Lighting towers and metal structures at night, the renaissance of the Saudi national economy, oil factories and plants in the Kingdom of Saudi Arabia, oil and gas refinery, the concept of petroleum engineering in the Gulf countries, large and huge warehouses and tanks, petrochemical industries and projects
Renaissance of the Saudi national economy, the concept of petroleum engineering in the Gulf countries, petrochemical industries and projects, gas refinery, view of large and huge warehouses and tanks, oil factories and laboratories in the Kingdom of Saudi Arabia
Petrochemical industries and projects, the concept of petroleum engineering in the Gulf countries, the gas refinery, the renaissance of the Saudi national economy, the view of large and huge warehouses and tanks at sunset, oil factories and laboratories in the Kingdom of Saudi Arabia
Towers and metal structures in desert lands, oil and gas refineries, petrochemical industries and projects, the concept of petroleum engineering in the Gulf countries, the renaissance of the Saudi national economy, large and huge warehouses and tanks, fuel factories and mines in the Kingdom of Saudi Arabia
Pipelines and steel cables, Petrochemical industries and projects, Oil and gas refinery in the industrial area, Factories and plants in the Kingdom of Saudi Arabia, Industrial engineering and equipment, Huge and large warehouses, View of smoke from large industrial facilities at sunset
Oil and gas refinery, lighting towers and metal structures, oil factories and plants in the Kingdom of Saudi Arabia, the concept of petroleum engineering in the Gulf countries, petrochemical industries and projects, the renaissance of the Saudi national economy, large and huge warehouses and tanks
Petrochemical industries and projects, oil and gas refineries, the concept of petroleum engineering in the Gulf countries, the renaissance of the Saudi national economy, towers and metal structures in desert lands, large and huge warehouses and tanks, fuel factories and plants in the Kingdom of Saudi Arabia
Large and huge warehouses and tanks, pipelines and steel cables, the renaissance of the Saudi national economy, the concept of petroleum engineering in the Gulf countries, oil factories and plants in the Kingdom of Saudi Arabia, petrochemical industries and projects, an aerial view of an oil and gas refinery
Oil refineries in Saudi Arabia, petrochemical projects contributing to the renaissance of the Saudi national economy, gas plants and refineries, the concept of petroleum engineering in the Gulf countries, towers and metal structures at sunset, large and huge warehouses and tanks
Follow up the progress of work in factories, the concept of gas productivity in Saudi Arabia, metal and chemical industries, steel cables and pipelines, work in the field of petrochemical industries and projects, a group of Saudi Gulf Arab engineers working in an oil and gas refining plant
Quality of machinery and equipment in factories that extract oil wealth from the depths of the seas, the concept of petroleum engineering in the Gulf States, oil and gas refinery, petrochemical industries and projects, the renaissance of the Saudi national economy, oil factories in the Kingdom of Saudi Arabia
Oil factories and plants in the Kingdom of Saudi Arabia, the renaissance of the Saudi national economy, lighting towers and metal structures, oil and gas refinery, the concept of petroleum engineering in the Gulf countries, large and huge warehouses and tanks, petrochemical industries and projects
Petrochemical industries and projects, oil and gas refineries, the concept of petroleum engineering in the Gulf countries, the renaissance of the Saudi national economy, towers and metal structures in desert lands, large and huge warehouses and tanks, fuel factories and plants in the Kingdom of Saudi Arabia
The concept of gas production in Saudi Arabia. Monitoring the workflow in factories, pipelines and steel cables. A close-up photo from the back of a Saudi Gulf Arab engineer wearing a helmet and protective vest in an oil refining plant. Working in the field of petrochemical industries and projects.
Machines for large industrial facilities for petroleum production, oil and gas refineries, petrochemical projects contributing to the renaissance of the Saudi national economy, oil factories and laboratories in the Kingdom of Saudi Arabia, lighting towers and metal structures at night.
The quality of machinery and equipment in oil extraction plants, petroleum refining plants in the Kingdom of Saudi Arabia, the concept of work in the industrial engineering sector, modern technologies in oil and gas production.
Smoke rising from factories and polluting the environment, industrial plants in the Kingdom of Saudi Arabia, development industries contributing to the renaissance of the Saudi national economy, large and huge warehouses and tanks, an industrial station with towers and metal structures at sunset, reliance on local national production
Oil factories and plants in the Kingdom of Saudi Arabia, petrochemical projects contributing to the renaissance of the Saudi national economy, oil and gas refinery, the concept of petroleum engineering in the Gulf States, lighting towers and metal structures at sunset, large and huge warehouses and tanks
Fuel factories and mines in Saudi Arabia, large and huge warehouses and tanks, towers and metal structures in desert lands, oil and gas refineries, petrochemical industries and projects, the concept of petroleum engineering in the Gulf countries, the renaissance of the Saudi national economy
Large and massive storage tanks, towers and metal structures in desert lands, oil and gas refineries, petrochemical industries and projects, the concept of petroleum engineering in the Gulf countries, the renaissance of the Saudi national economy, fuel factories and mines in the Kingdom of Saudi Arabia
Oil factories and plants in the Kingdom of Saudi Arabia, environmental pollution from smoke from oil and gas refineries, the concept of petroleum engineering in the Gulf States, petrochemical industries contributing to the renaissance of the Saudi national economy, large and huge warehouses and tanks, lighting towers and structures at night
Large and huge warehouses, industrial engineering and equipment, petrochemical industries and projects, steel pipelines and cables, oil and gas refining plant in the industrial area, factories and plants in the Kingdom of Saudi Arabia
Petrochemical industries and projects, the concept of petroleum engineering in the Gulf States, the renaissance of the Saudi national economy, towers and metal structures in desert lands, large and huge warehouses and tanks, oil and gas refineries, fuel factories and mines in the Kingdom of Saudi Arabia
The concept of work in the industrial engineering sector, the quality of machinery and equipment in oil extraction plants, modern technologies in the production of oils and gas, oil refineries in the Kingdom of Saudi Arabia, a picture of a fuel plant from the inside, the development and progress in the technologies used in manufacturing processes
Huge and large warehouses, petrochemical industries and projects, industrial engineering and equipment, factories and plants of the Kingdom of Saudi Arabia, oil and gas refining plant in the middle of the sea, refinery smoke factories
Oil and gas refineries, petrochemical industries and projects, the concept of petroleum engineering in the Gulf countries, the renaissance of the Saudi national economy, towers and metal structures in desert lands, large and huge warehouses and tanks, fuel factories and plants in the Kingdom of Saudi Arabia
Oil and gas refining plant in the industrial area, petrochemical industries and projects, view of smoke from factories in the air at sunset, steel pipelines and cables, factories and plants in the Kingdom of Saudi Arabia, industrial engineering and equipment, huge and large warehouses
Pipelines and steel cables, Oil and gas refinery in the industrial area, Petrochemical industries and projects, Pollution resulting from oil production, Factories and plants in the Kingdom of Saudi Arabia, Huge and large warehouses, Industrial engineering and equipment
Smoke rising from factories and polluting the environment, industrial plants in the Kingdom of Saudi Arabia, development industries contributing to the renaissance of the Saudi national economy, large and huge warehouses and tanks, an industrial station with towers and metal structures at sunset, reliance on local national production
Petrochemical projects contribute to the renaissance of the Saudi national economy, oil factories and plants in the Kingdom of Saudi Arabia, the concept of petroleum engineering in the Gulf States, lighting towers and metal structures at dawn, large and huge warehouses and tanks, oil and gas refinery
Petrochemical industrial projects, economic growth and progress, oil production in Saudi Arabia, view of smoke from factories in the air, huge industrial engineering, equipment and warehouses, close-up of oil and gas refinery at sunset
Oil production in the Kingdom, Factories and plants in Saudi Arabia at sunset, Industrial engineering and equipment, Petrochemical industries and projects, Economic growth and progress, Factory smoke refinery, Oil and gas refining plant, Huge and large warehouses, View of factory smoke in the air
Monitoring the progress of work in factories and plants, two Saudi Arabian Gulf engineers wearing protective vests and helmets working in an oil and gas refinery, working in the field of petrochemical industries and projects, steel pipelines and cables, the concept of gas productivity in Saudi Arabia
Renaissance of the Saudi national economy, the concept of petroleum engineering in the Gulf countries, metal towers and structures in the desert, oil and gas refineries in the Kingdom of Saudi Arabia, large and huge warehouses and tanks, petrochemical industries and projects.
Engineering and urban development of oil refineries in the Kingdom of Saudi Arabia, oil mines on soft golden sands, harsh and dry climate, adoption of modern techniques and technology in oil and gas production, petrochemical industries and projects, huge and modern tools and equipment
Lighting of towers and metal structures at night, the renaissance of the Saudi national economy, oil factories and plants in the Kingdom of Saudi Arabia, oil and gas refinery, the concept of petroleum engineering in the Gulf countries, large and huge warehouses and tanks, petrochemical industries and projects
Oil and gas refinery, petrochemical industries and projects, the concept of petroleum engineering in the Gulf countries, the renaissance of the Saudi national economy, lighting towers and metal structures at sunset, large and huge warehouses and tanks, oil factories and laboratories in the Kingdom of Saudi Arabia
Use of modern techniques and technology in gas production in Saudi Arabia, a picture from the back of a Saudi Arabian Gulf man wearing a helmet and a protective vest following the progress of factory work, engineering professions and jobs, oil refinery background, quality of oil production plants and equipment
Engineering and urban development of oil refineries in the Kingdom of Saudi Arabia, oil refinery on soft golden sands, harsh and dry climate, adoption of modern techniques and technology in oil and gas production, petrochemical industries and projects, huge and modern tools and equipment
Smoke rising from factories and polluting the environment, industrial plants in the Kingdom of Saudi Arabia, development industries contributing to the renaissance of the Saudi national economy, large and huge warehouses and tanks, an industrial station with towers and metal structures at sunset, reliance on local national production
Huge and large warehouses, engineering and industrial equipment, factories and laboratories in the Kingdom of Saudi Arabia, oil and gas refining plant, Dukhan laboratories refinery, petrochemical industries and projects, white background
The concept of gas production in the Kingdom of Saudi Arabia, Saudi jobs and professions, following up on the progress of work in factories, a close-up photo from the back of a Saudi Gulf Arab engineer wearing a helmet and a protective vest standing between pipelines at sunset, background of an oil refining plant
Concept of work in the industrial engineering sector, oil refineries in Saudi Arabia, quality of machinery and equipment in oil extraction plants, close-up of the NAFC refinery illuminated at night, use of modern technologies in oil and gas production
Huge machinery and heavy equipment used in petroleum exploration, work in the field of petroleum engineering, oil and gas refining plants in the industrial zone in Saudi Arabia, extracting underground resources from the sea, petrochemical industries and projects in the Kingdom, Saudi economic growth and progress
Oil and gas refineries, petrochemical industries and projects, petroleum engineering concept in the Gulf countries, renaissance of the Saudi national economy, towers and metal structures in desert lands
Petrochemical industries and projects, oil and gas refineries, the concept of petroleum engineering in the Gulf countries, the renaissance of the Saudi national economy, towers and metal structures in desert lands, large and huge warehouses and tanks, fuel factories and plants in the Kingdom of Saudi Arabia
Engineering and urban development of oil refineries in the Kingdom of Saudi Arabia, oil refinery on soft golden sands, harsh and dry climate, adoption of modern techniques and technology in oil and gas production, petrochemical industries and projects, huge and modern tools and equipment
Lighting towers and metal structures in the evening, petrochemical industries and projects, oil and gas refinery, concept of petroleum engineering in the Gulf countries, renaissance of the Saudi national economy, oil factories and plants in the Kingdom of Saudi Arabia, large and large warehouses and tanks
Large and massive warehouses and tanks, lighting towers and metal structures at night, oil factories and laboratories in the Kingdom of Saudi Arabia, the concept of petroleum engineering in the Gulf countries, oil and gas refineries, petrochemical industries and projects, the renaissance of the Saudi national economy
Factories and plants in Saudi Arabia, Oil and gas refinery in industrial area, Steel pipelines and cables, Petrochemical industries and projects, Pollution resulting from oil production, Huge and large warehouses, Industrial engineering and equipment
Working in the field of petrochemical industries and projects, steel pipelines and cables, the concept of gas productivity in the Kingdom of Saudi Arabia, following up on the progress of work in factories and plants, a group of Saudi Gulf Arab engineers working in an oil and gas refining plant
The concept of petroleum engineering, oil and gas refinery, petrochemical industries and projects, the renaissance of the Saudi national economy, oil factories in the Kingdom of Saudi Arabia, the quality of machinery and equipment in factories that extract oil wealth from the depths of the sea
Quality production and manufacturing, achieving the industrial revolution, adopting modern techniques and technology in engineering, a close-up photo of a Saudi-Gulf Arab engineer wearing glasses and a safety helmet inspecting oil and gas equipment in the factory, Saudi professions and jobs
Pipelines extending from the depths of the sea to the refineries, working in the field of petroleum engineering, oil and gas refinery, a picture from the back of two Saudi Arabian Gulf workers wearing protective suits and helmets supervising oil plants and factories in the Kingdom of Saudi Arabia
Petrochemical industries and projects, huge and large warehouses, engineering and industrial equipment, factories and laboratories in the Kingdom of Saudi Arabia, oil and gas refining plant in the middle of the sea, Dukhan refinery laboratories.
Work progress at work site, a, Back view of two Saudi Arabian Gulf workers wearing orange protective suits and helmets Oil and gas refinery, pipelines extending from the depths of the sea to the refineries, working in the field of petroleum engineering in the Kingdom of Saudi Arabia
Oil refinery on soft golden sands, harsh and dry climate, adoption of modern techniques and technology in oil and gas production, petrochemical industries and projects, huge and modern tools and equipment, engineering and urban development of oil refineries in the Kingdom of Saudi Arabia
Renaissance of the Saudi national economy, oil factories in the Kingdom of Saudi Arabia, quality of machinery and equipment in factories extracting oil wealth from the depths of the seas, the concept of petroleum engineering, oil and gas refinery, petrochemical industries and projects
Oil and gas refineries in the industrial zone in Saudi Arabia, Extracting underground resources from the sea, Petrochemical industries and projects in the Kingdom, Huge machines and heavy equipment used in oil exploration, Working in the field of petroleum engineering, Saudi economic growth and progress
Petrochemical industries and projects, pipelines and steel cables, illustrations of an oil and gas refining plant, factories and laboratories in the Kingdom of Saudi Arabia, huge and large warehouses, industrial cityscape
Monitoring the progress of work in factories and laboratories, the concept of gas productivity in the Kingdom of Saudi Arabia, Saudi professions and jobs, a close-up photo from the back of a Saudi Gulf Arab engineer wearing a helmet and a protective vest standing between pipelines at sunset, the background of an oil refining plant
View of factory smoke spreading in the air at sunset, oil and gas refining plant, petrochemical industrial projects, economic growth and progress, oil production in the Kingdom of Saudi Arabia
Engineering and urban development of oil refineries in the Kingdom of Saudi Arabia, oil refinery on soft golden sands, harsh and dry climate, adoption of modern techniques and technology in oil and gas production, petrochemical industries and projects, huge and modern tools and equipment
The concept of petroleum engineering in the Gulf countries, lighting towers and metal structures at sunset, large and huge warehouses and tanks in desert areas, petrochemical projects contributing to the renaissance of the Saudi national economy, oil factories and plants in the Kingdom of Saudi Arabia, gas refinery
Petrochemical industries and projects, engineering and urban development of oil refineries in the Kingdom of Saudi Arabia, oil refinery on soft golden sands, harsh and dry climate, adoption of modern techniques and technology in oil and gas production, huge and modern tools and equipment
Petrochemical industries and projects, engineering and urban development of oil refineries in the Kingdom of Saudi Arabia, oil refinery on soft golden sands, adoption of modern techniques and technology in gas production, huge and modern tools and equipment
The concept of petroleum engineering in the Gulf countries, petrochemical industries and projects, gas refinery, the renaissance of the Saudi national economy, the view of large and huge warehouses and tanks, oil factories and laboratories in the Kingdom of Saudi Arabia
An oil and gas refining plant in the industrial zone in Saudi Arabia, steel pipelines, a fire consuming the pipes connecting parts of the manufacturing and refining machine within the sea, petrochemical industries and projects, pollution and leakage of oil into seawater
Engineering and urban development of oil refineries, side view of oil refinery in the desert of Saudi Arabia, harsh and dry climate, huge and modern tools and equipment, adoption of modern techniques and technology in oil and gas production, soft golden sand dunes
Factories and plants in Saudi Arabia, Oil and gas refinery in industrial area, Steel pipelines and cables, Petrochemical industries and projects, Pollution resulting from oil production, Huge and large warehouses, Industrial engineering and equipment
Factories and laboratory engineering in the industrial zone in the Kingdom of Saudi Arabia, petrochemical industries and projects, huge and large warehouses, pipelines and cables, steel equipment.
The use of modern techniques and technology in oil and gas production in the Kingdom of Saudi Arabia, the quality of oil production laboratories and equipment, a picture from the back of a Saudi-Gulf Arab man wearing a helmet and a protective vest following the progress of the factory’s work, Saudi professions and jobs, oil refinery background