Method for controlling the downhole temperature during fluid injection into oilfield wells

An apparatus to deliver fluid to a subterranean formation, comprising:

• a pump configured to deliver fluid to a wellbore;
• a flow path configured to receive fluid from the pump;
• a bottom hole assembly comprising a fluid outlet and a temperature sensor and configured to receive fluid from the flow path, the temperature sensor configured to measure a downhole injection temperature of the fluid;
• and
• a controller configured to accept information from the temperature sensor and to send a signal to the pump or the bottom hole assembly to control operation of the pump, the fluid outlet, and the bottom hole assembly to maintain a required downhole injection temperature of the fluid through the use of a Joule Thomson effect.

A method of using a fluid within a subterranean formation, comprising:

• forming a fluid comprising a fluid additive, the fluid formed by a mixture of a treatment fluid and a fluid additive;
• pumping the fluid to a formation with a pump, a flow path, and a bottom hole assembly;
• observing a downhole fluid injection temperature with a temperature sensor;
• sending a signal from the temperature sensor to a controller;
• and
• sending a signal from the controller to the pump to control operation of the pump, to control operation of the bottom hole assembly, and to control a proportion of the mixed treatment fluid and fluid additive to change the downhole fluid injection temperature through the use of a Joule Thomson effect and thereby control the functionality of the fluid.