METHOD FOR WELL BORE ZONE TREATMENT Russian patent published in 2006 - IPC E21B43/25 

FIELD: mining, particularly to develop well and to increase well output which has reduced as a result of well zone mudding with asphalt-tar-paraffin deposits and mechanical injuries.

SUBSTANCE: method involves lowering flow string in well; creating depression pressure drop between well bore zone and well interior by forming periodical pressure pulses in well bore zone by way of blast wave moving via well interior. Lower flow string end is provided with profiled channel and two hydroimpulsive devices arranged one over another. The hydroimpulsive devices have pressure tanks with inlet and outlet valves. Outlet valve of upper pressure tank and inlet valve of lower pressure tank have increased opening speeds. The pressure tanks are connected with profiled channel directed to well bore. Outlet valve of upper pressure tank is opened as maximal pressure is obtained at well bottom. Inlet valve of lower pressure tank is opened as minimal pressure is formed at well bottom. Inlet valve of upper pressure tank and outlet valve of lower pressure tank are made as check valves to communicate the pressure tanks with well interior. During well treatment flow string is moved along well length.

EFFECT: possibility to create alternating increased and decreased pressure pulses having large amplitudes and sharp edges.

1 dwg