Combined unclogging method for coiled tubes of horizontal well

Abstract

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 effect of the foam is great, flowback based on the negative pressure is carried out thoroughly, the operation is convenient, and the construction cycle is short.

Description

Technical field [0001] The invention belongs to the technical field of oil and gas well plugging removal, and specifically relates to a horizontal well coiled tubing composite plugging removal method. Background technique [0002] In the long-term production process of oil and gas wells, sand blasting often occurs in the formation, wax, gum, and asphaltene in the crude oil are precipitated, and the phenomenon of scaling will inevitably cause sand sedimentation in the wellbore, scaling on the well wall, and blockage of seepage channels near the well. The formation of compound blockage seriously affects the productivity of oil and gas wells. [0003] Regarding composite plugging horizontal wells, the prior art mainly uses a single form of plugging removal such as mechanical sand washing and scale removal and conventional acidification. The disadvantages of these processes are as follows: formation pressure is low, the well flushing fluid leakage is serious when the wellbore is flush...

AI Technical Summary

Problems solved by technology

The defects of these processes are as follows: the formation pressure is low, the wellbore flushing fluid is seriously lost during sand flushing, and the water consumption is large, resulting in slow or even impossible recovery of oil well productivity after the measures are taken; long construction period for tubing drilling and descaling, and easy damage to t...

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