Keshen gas field is located at Kuqa foreland area of Tarim Basin, western China. The surface is mountainous, the environment is tough and the ecosystem is fragile. Through seven years’ development of this field, a natural gas productivity of 5 billion cubic meters per year was obtained by drilling 45 ultra-deep HPHT wells and building a pipeline system of 140km long with zero environment pollution. 41 towns and 4 million residents benefited from this project.

The location of processing plant and pipeline network pattern were selected through node analysis and topology analysis. A fishbone-like pipeline system was selected to avoid the mountainous area and minimize disturbance to the local environment. High-pressure throttling refrigeration technique and high-efficient gas separation technique were also used, reducing the energy consumption for processing by 45%. Electricity was used in drilling instead of diesel, which reduced CO2 emission by 220,000 tons. 140MPa wellhead and 13Cr tubing were used to maintain well integrity. Processing and recycling of oil-based drilling fluids, flow-back fracturing fluids, etc. were also conducted to avoid environmental pollution.

By July 2015, Keshen gas field was successfully established with natural gas productivity of 5 billion cubic meters per year. No pollution to the environment and no harm to the ecosystem occurred. No personal injuries were encountered during 27 million man-hours. A road in the mountainous area which is 108km long was built for the gas field and shared by the local residents. Based on Keshen gas field, a gas supply project was established with cooperation with local government, changing the local fuel type from firewood to clean natural gas, which reduces the annual emission of SO2, NO2 and CO2 by 790 tons, 660.27 tons and 61,500 tons respectively. More than 2,000 job opportunities in the gas field were created for the local Uygur and other minority residents. Totally, 41 towns with 4 million residents benefited from this project. The increase rate of the GDP of Baicheng city was doubled with influence of this project. Not only satisfying the local use, the natural gas produced from Keshen gas field is also transported to eastern coastal cities like Shanghai, Nanjing.

Keshen gas reservoir is an ultra-deep HPHT reservoir with buried depth from 6500m to 8000m, temperature from 150°C to 182°C and pressure from 116 MPa to 136 MPa. With use of many advanced technologies, the reservoir was not only efficiently developed, but with no injuries and no pollution to the environment. It also significantly boosts local community development. It provides a good reference for the development of unconventional reservoirs in the world.

You can access this article if you purchase or spend a download.