A multi-cluster flow-limiting fracturing method for horizontal wells with perforation sub-clusters

Abstract

The invention provides a method for segmented multi-cluster flow-limiting fracturing in a horizontal well with perforation sub-clusters. The specific steps are as follows: Step 1, determine the number of perforation clusters in the fracturing section and the positions of each perforation cluster; Step 2, each Multiple perforation sub-clusters are set at the position of the perforation cluster, and the distance between the perforation sub-clusters is not less than 2 m and not more than 8 m. Perforation cluster; Step 4, fracturing operation, multiple sub-clusters of the perforation cluster will initiate fractures and tend to extend along different directions on both sides of the wellbore, forming nearly uniform and symmetrical hydraulic fractures on both sides of the wellbore at the position of the perforation cluster in the section . In the present invention, utilizing the flow-limiting effect of the perforation holes, the fractures start from the perforation clusters and expand to both sides of the horizontal wellbore respectively, thereby forming nearly uniform and symmetrical hydraulic fractures on both sides of the wellbore at each perforation cluster position. Therefore, the purpose of reducing the generation of invalid perforation clusters and improving the degree of reservoir stimulation can be achieved.

Description

technical field [0001] The invention relates to a segmented multi-cluster flow-limiting fracturing method for a horizontal well with perforation sub-clusters, and belongs to the field of oil gas and geothermal reservoir reconstruction. Background technique [0002] Horizontal well staged multi-cluster fracturing is currently the main means of developing tight oil and gas resources and hot dry rock geothermal resources. In this method, the horizontal wellbore is segmented by running bridge plugs first, and perforating guns are used to perforate multiple positions on the casing in the segment, which is called multi-cluster. Usually, each fracturing stage has 3-12 clusters of perforations, the cluster spacing is between 10-30 m, and the length of each perforation cluster on the casing is between 0.2-2 m. Then pump fracturing fluid into the section with a large displacement and a large amount of fluid, in order to realize the simultaneous initiation and expansion of hydraulic f...

AI Technical Summary

Problems solved by technology

[0005] In order to overcome the problem in the prior art that multiple fractures will expand outward alternately on one side of the wellbore, the present invention provides a segmented multi-cluster current-limiting fracturing method for horizontal wells with perforation sub-clusters. Perforate at a predetermined position in the section to form a perforation cluster with perforation sub-clusters for fracturing. During the fracturing process, the construction displacement is increased step by step. Affected by the heterogeneity of reservoir rocks and within the perforation limit Under the action of the flow effect, multiple sub-clusters of the perforation cluster will crack and tend to extend in different directions on both sides of the wellbore, forming nearly uniform and symmetrical hydraulic fractures on both sides of the wellbore at the position of the perforation cluster in the section, thereby improving the storage capacity. Layer Transformation Degree Purpose

Images