Continuous oil pipe sectional sand-blasting perforation casing fracturing pipe column and casing fracturing method

Abstract

The invention discloses a continuous oil pipe sectional sand-blasting perforation casing fracturing pipe column and a casing fracturing method, which are suitable for application in vertical wells and horizontal wells in the petroleum industry, in particular for sectional fracturing of unconventional oil-gas reservoir horizontal wells such as tight sandstone wells. The fracturing pipe column comprises a safety joint, a centralizer, a hydraulic jet tool and a reverse circulation valve, which are connected to a continuous oil pipe in sequence, wherein a mechanical continuous oil pipe fracturing packer is connected below the reverse circulation valve. The sectional casing fracturing method is used for placing the fracturing pipe column provided with the mechanical continuous oil pipe fracturing packer into a casing in a well through the continuous oil pipe; and by the method, a fracturing well section closest to the bottom of the well is fractured at first, and then the fracturing well section is packed by using the mechanical continuous oil pipe fracturing packer. By the continuous oil pipe sectional sand-blasting perforation casing fracturing pipe column and the casing fracturing method, a sand stopper is not needed as an isolation section, so that the sand stopper is not needed to be subjected to back flushing, the production cost is reduced, and multi-layer section fracturing operation for a short horizontal well section or straight well section can be realized.

Description

technical field [0001] The present invention relates to casing sanding fracturing completion method and tools in the petroleum industry, in particular to a coiled tubing segmental sand blasting perforation casing fracturing string and segmental fracturing method, suitable for ultra-deep vertical wells and Applied in horizontal wells, especially suitable for staged fracturing of horizontal wells in unconventional oil and gas reservoirs such as tight sandstone. Background technique [0002] The method of applying coiled tubing jet casing segmental fracturing at home and abroad is to use coiled tubing to run a string of strings with hydraulic jet tools in a casing cemented and completed horizontal well. , Casing sand fracturing. After fracturing a section, a section of sand plug is left in the casing as an isolation, and the string is dragged to the next section for sandblasting and fracturing. This method uses casing fracturing, which can achieve larger scale fracturing. Ho...

AI Technical Summary

Problems solved by technology

This process has limitations such as a long construction period, fracturing fluid flowback does not pollute the oil layer in time, a long horizontal section is required to fill the liquid rubber plug, and it is difficult to flush.

Patent No. 200810105643 "Packer Sealing Multi-Layer Hydraulic Sandblasting and Fracturing Integrated Process Method" and Patent No. 200710129818 "Horizontal Well Mechanical Segmented Fracturing Tool String" adopt hydraulic expansion type sealing The ordinary tubing of the spacer does not move the tubing string into sections, and balls of different diameters are thrown step by step to open the sliding sleeve to realize segmental fracturing. Due to the limited diameter of the tubing, it is also unable to meet the needs of large-scale fracturing; on the other hand, Since balls of different diameters need a certain level difference, the maximum number of segments is also limited by the size of the casing, so more levels of fracturing cannot be achieved

The patent number is 200720169453 "Horizontal Well One-time Lifting Fracturing String", which uses ordinary tubing to drag the packer up and back for fracturing section by section. Since the inner diameter of the tubing is smaller than that of the casing, large-scale fracturing cannot be achieved; After a section of fracturing is completed, it is necessary to wait for the formation pressure to fully diffuse before dragging the pipe string, resulting in a long construction period, low construction efficiency, and delayed flowback of fracturing fluid to pollute the oil layer

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