2.3.5.1. Mineralization degree of field flowback fluid
Fig. 6 illustrates the change of mineralization degree of flowback fluids from Well CH201 with time. It is determined that, the volume of flowback fluids decreases with time, while its mineralization degree rises sharply after passing through an inflection point.
Fig. 6. Change of mineralization degree and volume of flowback fluid with time.
Reasons for the increase in mineralization degree of flowback fluids include salt dissolution in fracturing fluid, liquid-carrying effect of methane and salt discharging from micro- to nano-pores.