【中文版】

“西气东输”是指从中国西部地区向东部地区输送天然气。这一工程是中国的一项重大能源战略，旨在通过将天然气从西部输送到东部，以满足东部地区日益增长的能源需求，同时也促进了西部地区经济发展。

“西气东输”输送的天然气主要来自中国西部地区的天然气田，如塔里木盆地、准噶尔盆地等。这些地区拥有丰富的天然气资源，开采成本相对较低。通过将天然气从西部输送到东部，可以满足东部地区日益增长的能源需求，同时也降低东部地区的能源成本。

“西气东输”工程分为两期，一期工程共建设了三条输气管道，总长度超过4000公里。这些输气管道从西部地区的天然气田向东部地区输送天然气。二期工程又增加了两条输气管道，总长度超过3000公里。这些输气管道的建设和运营由中国石油天然气集团公司负责。

“西气东输”工程的实施，不仅满足了东部地区日益增长的能源需求，降低了能源成本，同时也促进了西部地区经济发展。在工程建设期间，大量使用西部地区的原材料和劳动力，为当地经济发展提供了机会。在运营期间，天然气输送也带动了相关产业的发展，如燃气发电、化工等。

总之，“西气东输”是中国的一项重大能源战略，对于满足东部地区日益增长的能源需求、促进西部地区经济发展具有重要意义。

【英文版】

"West-to-East Gas Transmission" refers to the transmission of natural gas from the western to the eastern regions of China. This is a major energy strategy for China, aiming to meet the growing energy demand in the eastern region by transmitting natural gas from the west, while also promoting economic development in the western region.

The "West-to-East Gas Transmission" mainly involves natural gas fields in the western regions of China, such as the Tarim Basin and the Junggar Basin. These regions have abundant natural gas resources and relatively low extraction costs. By transmitting natural gas from the west to the east, it can meet the growing energy demand in the eastern region and also reduce energy costs in the eastern region.

The "West-to-East Gas Transmission" project is divided into two stages. In the first phase, three gas pipelines were constructed with a total length of over 4,000 kilometers. These pipelines transport natural gas from natural gas fields in the western region to the eastern region. In the second phase, two additional gas pipelines were added, with a total length of over 3,000 kilometers. The construction and operation of these pipelines are managed by the China National Petroleum Corporation (CNPC).

The implementation of the "West-to-East Gas Transmission" project not only meets the growing energy demand in the eastern region, reduces energy costs, but also promotes economic development in the western region. During the construction period, a large amount of raw materials and labor were used from the western region, providing opportunities for local economic development. During operation, natural gas transmission also drives the development of related industries such as gas-fired power generation and chemicals.

In summary, "West-to-East Gas Transmission" is a major energy strategy for China that has great significance for meeting the growing energy demand in the eastern region and promoting economic development in the western region.