METHOD FOR WELL CLEANING OF ASPHALT-TAR-PARAFFIN AND SULFIDE DEPOSITS Russian patent published in 2005 - IPC

FIELD: oil production industry, particularly to remove asphalt-tar-paraffin and sulfide deposits and composite precipitations from flow string of production well.

SUBSTANCE: method involves detecting area of asphalt-tar-paraffin and sulfide deposit forming on flow string surface; performing cyclic working agent injection in the well; controlling degree of flow string cleaning of deposits. At the beginning of asphalt-tar-paraffin and sulfide deposit formation universal coupling provided with flushing valve is installed on the flow string. The flushing valve is suction valve of sucker-rod pump. Working agent is preliminary heated and pumped over closed loop including well head-hole annuity-flushing valve-universal coupling-flow string-well head. Before working agent injection into hole annuity the working agent is additionally heated at well head. The working agent is heat carrier, namely oil or processing medium. Degree of flow string cleaning of asphalt-tar-paraffin and sulfide deposits and degree of removing thereof from the well is controlled by estimating current magnitude of pump motor or by lowering sample in the flow string.

EFFECT: increased efficiency of asphalt-tar-paraffin and sulfide deposits and increased time between well cleaning and repair operations.

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