DEVICE FOR CONTROL OF BEHIND-CASING FLOWS BETWEEN TWO FORMATIONS Russian patent published in 2016 - IPC E21B47/11 

FIELD: oil and gas industry.

SUBSTANCE: device for control of behind-the-casing flows between two formations comprises a container for tracer fluid run in at the logging cable with delivery unit and depressurization unit as well with measurement sensor. Ferrofluid is used as tracer fluid and devices for magnetic field measurement are used as measurement sensors. The container is placed to the pipe string equipped from outside with a packer set between the upper and lower formations. The delivery unit is installed in the pipe string above the packer opposite the upper formation and made as a filter blinded from the bottom and perforated plug rigidly fixed in the pipe string above the filter. At that the depressurization unit is made as a stepped rod with larger D diameter at the top and less d diameter at the bottom. In transportation position the stepped rod with larger D diameters is installed hermetically to the central opening made at the container bottom, and in working position at interaction of the stepped rod with perforated plug in the delivery unit the stepped rod can be moved axially upwards in regard to the container placing the stepped rod with less d diameter opposite the central opening in the container. The measurement sensor is placed at the lower end of the pipe string opposite the lower formation.

EFFECT: improved operational reliability of the device, improved efficiency of the device operation, improved accuracy for determination of behind-the-casing flow between the two formations, excluding encapsulation of the logging cable at the wellhead.

3 dwg