Combined unclogging method for coiled tubes of horizontal well

• Main Authors: JIANG ZHIQIANG, LIU JIANGBO, ZHANG XIONGTAO, JU YAFENG, LIU ZHONGNENG, BAI XIAOPEI, ZHAO PENGYU, LI XUMEI, LUO YOUGANG, LIANG WANYIN
• Format: Patent
• Language: Chinese; English
• Published: 25.12.2018
• Subjects: EARTH DRILLING; EARTH DRILLING, e.g. DEEP DRILLING; FIXED CONSTRUCTIONS; MINING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR ASLURRY OF MINERALS FROM WELLS

The invention discloses a combined unclogging method for coiled tubes of a horizontal well. According to the method, the coiled tubes are adopted, the impact force of a rotary ejection tool is utilized to crush a shaft casting bed and well wall dirt, a nitrogen foam acid is adopted for dissolving obstructions near the well, flowback for unclogging an oil flow passage is achieved through the negative pressure of the foam, and other approaches similar to the approaches above are also used for combined unclogging. The method includes the steps of 1, installation of the coiled tubes and underground tool strings; 2, foam (acid) liquid preparation and debugging; 3, ejection on shafts for removing sand and dirt; 4, acidization and unclogging through dragging of the foam acid; 5, flowback for cleaning through the negative pressure of the foam. Combined unclogging is carried out to recover the productivity of the oil well. A rotary ejection crushing mode is adopted, the impact is strong, the acidization and unclogging