A method of staged fracturing with cluster perforation for horizontal wells

Abstract

The invention discloses a horizontal well cluster perforation staged fracturing method. The horizontal well cluster perforation staged fracturing method comprises the steps that the number of clusterof the first stage of the perforation is 2-4; the number of the cluster of other per stage perforation is set to be 6 or more; each cluster has four perforations, and the four perforation charges exhibit a 90-degree phase angle, so that the four perforations are located in the same plane in the direction perpendicular to a horizontal wellbore; and the diameter of the perforation is 14.5 mm or more. The horizontal well cluster perforation staged fracturing method increases the number of clusters in a single segment by optimizing the perforation position and parameters such as the number of perforations, the perforation diameter, the perforation density and the phase angle, and forms a single crack in the single cluster; and then the fracturing construction parameters are optimized and the pretreatment techniques such as medium-high-viscosity acid gradual extraction and displacement are combined, and the multi-cluster cracks in the segments are simultaneously cracked and extended. The technology can effectively increase the number of artificial cracks and crack length, improve the complexity of cracks, improve the transforming volume of cracks, solve the problem of the limitation ofthe current technology, and maximize the effect of a reservoir yield-increasing effect.

Description

technical field [0001] The invention relates to the technical field of horizontal well fracturing, and more specifically relates to a horizontal well cluster perforation staged fracturing method. The invention can be used for segmental fracturing of horizontal wells in carbonate rock, sandstone, shale and other reservoirs. Background technique [0002] At present, the application of staged fracturing technology for horizontal wells is becoming more and more common, such as sandstone, carbonate rock, shale and coalbed methane. And the casing completion ratio of horizontal wells is above 80%. However, the combination of cluster perforation and bridge plug is generally used for fracturing operations in casing-completed horizontal wells. [0003] The cluster perforation in foreign countries generally adopts the spiral perforation mode, with multiple clusters in a single section, generally 3-8 clusters, and even more than 12 clusters. Generally, the cluster length is 0.3-0.6m, ...

AI Technical Summary

Problems solved by technology

Aiming at the problems of few effective fractures in a single stage, small fracture length and low complexity of each fracture caused by the existing horizontal well cluster perforation staged fracturing technology in China, the perforation position and parameters such as perforation number, aperture, and perforation By optimizing the density and phase angle, etc., the number of clusters in a single section is increased, and a single fracture is formed in a single cluster; then, through the optimization of fracturing construction parameters and the combination of medium and high viscosity acid gradually increasing displacement pretreatment technology, multiple clusters in a section can be formed. Simultaneous crack initiation and extension

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