Controlled variable density fluid for wellbore operations

摘要

Fluid systems may contain elements to provide changes in bulk fluid density in response to various environmental conditions. One environmental driver to the variable density is pressure; other environmental drivers include, but are not limited to, temperature or changes in chemistry. The variable density of the fluid is beneficial for controlling sub-surface pressures within desirable pore pressure and fracture gradient envelopes. The variability of fluid density permits construction and operation of a wellbore with much longer hole sections than when using conventional single gradient fluids.