LU Tingqing, HU Ming, LIU Mohan, DING Chunyan, WANG Xing
At present, China has commercially exploited shale gas in a large-scale. However, the shale gas development may bring risks for water resources and environments. By surveying water consumption, sampling and analyzing flowbacks from shale gas drill sites in Sichuan and Chongqing, it is shown that the total water consumption is huge for the shale gas development, i.e., each well consumes about 32000 m3 of water. On the other hand, potential risks of water pollution come from several sections during shale gas development:firstly, fracturing and drilling flowbacks produce water having high salinity, complex components and a variety of heavy metals; secondly, a huge amount of waste fluids and oil-based mud cuttings are produced in the drilling process; thirdly, drilling circulation loss often happens in shale gas development areas where caves, cracks and underground rivers largely exist; and fourthly, constructions of the ground engineering. Besides, storage pools are apt to spill and leak by heavy rain or other factors. Therefore, when shale gas is extracted from Sichuan and Chongqing, constructions, allocation of water resources, and developing treatment technology of flowbacks must be meticulous. It is important to prevent water resources from being consumed excessively and water environment from being polluted in the developing shale gas.
