Refracturing and reconstruction method of oil and gas well

Abstract

The invention discloses a refracturing and reconstruction method of an oil and gas well. The refracturing and reconstruction method of the oil and gas well includes the following steps that 1, an oldwell is prepared, and it is ensured that the oil and gas well is unobstructed and clean; 2, an expansion tubular column is lowered; 3, the expansion tubular column expands and covers an original casing pipe; 4, pressure is tested; 5, perforation is conducted, a perforation tool is lowered to a pre-perforation position to conduct perforation, and the pre-perforation position avoids an original fracturing section; and 6, fracturing is conducted. Compared with the prior art, the refracturing and reconstruction method has the beneficial effects that an existing subsidy tube technology is creatively applied to old well reconstruction of the oil and gas well, full coverage of the horizontal section of a wellbore is realized by lowering the expansion casing pipe once, subsequent perforation and fracturing only need to be avoided an old fracturing seam and are conduced according to the normal perforation fracturing operational procedures, compared with an existing old well reconstruction technology, controllability of the whole construction process of the refracturing and reconstruction method is good, and standardized operation is easily realized.

Description

technical field [0001] The invention belongs to the technical field of oil well construction, and in particular relates to a method for repeated fracturing reconstruction of oil and gas wells. Background technique [0002] Low-permeability oil and gas resources are widely distributed in my country. With the continuous deepening of exploration and development, the proportion of low-permeability oil reservoirs in my country's total proven reserves and produced reserves is getting higher and higher. Tight oil and gas, shale oil and gas, The proportion of unconventional oil and gas resources represented by oil and gas resources such as deep basin gas has increased year by year. [0003] The development of low-permeability oilfields generally has the following basic characteristics: (1) The natural production capacity of oil wells is low, and oil flows with industrial recovery value are formed after fracturing; (2) The seepage law does not follow Darcy's law and has a starting pre...

AI Technical Summary

Problems solved by technology

However, this technology has the following deficiencies: first, when the temporary plugging agent is pumped in for plugging, it is difficult to guarantee the plugging effect of multiple fractures, and it is necessary to solve the problem of plugging agent flow during multiple fracturing processes, and the construction is cumbersome; second, When the fracture plugging effect is not clear and inconsistent, if fracturing is carried out again, the initiation and extension of fractures will have great uncertainty, and it is difficult to guarantee the ideal stimulation effect

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