Method for repeated fracturing of horizontal well

Abstract

The invention discloses a method for repeated fracturing of a horizontal well. The method includes the steps that (1) parameter evaluation and optimization before repeated fracturing is conducted; (2)repeat fracturing is conducted along old fractures or novel holes are re-shot between the old fractures; (3) slickwater and carbon dioxide foam fracturing fluid are subjected to formulation optimization and preparation; (4) the slickwater and the carbon dioxide foam fracturing fluid are injected for main fracture fracturing or extension; (5) proppant injection construction is conducted; (6) replacement operation is conducted; (7) step (4) to (6) are repeated until construction is completed. The effect of repeated fracturing and reforming of a shale gas reservoir are greatly improved, the optimized results can effectively guide repeated fracturing construction, the reconstruction volume is greatly increased, the construction effect is significantly improved, and thus the greatest economicbenefits are obtained.

Description

technical field [0001] The invention relates to the technical field of oil exploitation, and furthermore, relates to a method for repeated fracturing of a horizontal well. Background technique [0002] At present, whether it is shale, sandstone or carbonate rock, the problem of refracturing horizontal wells is becoming more and more urgent. After a certain period of time after the first fracturing, the conductivity of the fracture will decrease continuously and even reach 0, and the volume of the original fracture structure will also gradually decrease, resulting in a decrease in production. After the production is lower than the economic limit, it is necessary to consider refracturing to restore or increase the production of the well and realize economical and effective development. Especially under the current low oil price conditions, through repeated fracturing of horizontal wells, the oil and gas area not affected by the original fractures can be continued to expand, o...

AI Technical Summary

Problems solved by technology

There is also a method of using double packers and single card, but due to the limited inner diameter of the pipe string, the fracturing displacement is limited

[0008] 2) The pertinence of fracturing parameters is poor

Considering that the induced stress produced by the first fracture will not completely disappear until the fracture is closed, and the double superimposed effect of the induced stress caused by production, and this superimposed effect is difficult to calculate accurately, the fracture initiation direction and cause of refracturing The impact of large fluid loss on construction parameters is uncertain, so the pertinence of refracturing parameters is greatly reduced