METHOD FOR PROTECTING HEAD OF INJECTION WELL AGAINST FREEZING Russian patent published in 2013 - IPC E21B36/00 

FIELD: oil and gas industry.

SUBSTANCE: setup of valves of the injection wellhead is performed in the form of closed circuits: an upper one filled with water, and a lower one filled with freon gas. Two heat exchanger, which are installed on the right shoulder of the circuit, are added to the upper circuit of the setup. The first heat exchanger is installed in the soil under the soil freezing boundary, and the second one is installed on the soil surface below a central gate valve of water pipeline. The first heat exchanger is used for maintaining water temperature in upper circuit of the setup not less than 5°C above zero, and the second heat exchanger is used for pumping of heat with freon gas from the surface to the soil where it is accumulated. Besides, wellhead valves, upper and lower circuits of the setup are heat-insulated by applying a heat-insulating paint till the soil freezing boundary.

EFFECT: improving operating stability of well head valve assemblies of an injection well in a full functional mode during seasonal decrease of environmental temperature below zero degrees Celsius, in cases of approved and unscheduled outages of water supply to the well.

3 cl, 1 dwg