Drag type packer-less hydraulic jet pulsating acid fracturing device and method

Abstract

The invention belongs to the field of oilfield exploitation, and particularly relates to a device and a method for performing acid fracturing in an oil and gas well reservoir stratum. The device comprises an upper conversion nipple, a centralizer, a spray gun, a lower conversion nipple and a guide joint which are connected in sequence, wherein the upper end of the conversion nipple is connected with a construction tube string. According to the device and the method, acid fracturing packing is performed by using a hydraulic entrainment packing effect produced by high-speed pulsating jet, the packer of the conventional acid fracturing tool is not required, and the problem of high probability of invalidation due to multiple setting and unblocking of the packer in the conventional tool is avoided; the depth for acid fracturing in the stratum can be increased by performing the acid fracturing using pulsating jet, so that the length of the fracturing fracture is increased; the device has a simple structure and is safe and reliable, the construction method is mature, and the construction cost is lower than that of the conventional technology; a water layer can be prevented from being penetrated in an acid fracturing process by adjusting the arrangement direction of a self-excited oscillation nozzle on the spray gun; a high-speed pulsating jet is formed through the self-excited oscillation nozzle arranged on the spray gun; a directional perforating hole is quickly formed and a compaction zone produced by perforating bullet explosive perforation is avoided.

Description

technical field [0001] The present invention belongs to the field of oilfield exploitation, in particular, relates to a device and method for acidizing and fracturing in oil and gas well reservoirs, and more specifically, relates to a non-sealed pulsating jet which is dragged by self-excited oscillating nozzles. Device and method for spacer acid fracturing. Background technique [0002] With the continuous exploitation of global oil and gas resources, the proportion of low-permeability geological reserves in the remaining reserves continues to increase. In addition, some old oilfield reservoirs have gradually entered a period of low-pressure depletion. Reservoir fracturing has become a new low-permeability block and old oilfield. Basic technology of oil and gas development in depleted reservoirs. Usually, in some oil and gas wells, it is necessary to perform multi-stage fracturing of the reservoir at a certain distance along the wellbore, and the fractures must reach suffic...

AI Technical Summary

Problems solved by technology

Mechanical packers can be used to implement separate layers or multi-stage fracturing in cased wells, but it is prone to sand stuck pipe strings leading to downhole accidents, and the packer is corroded by acid liquid, and the isolation effect becomes poor after repeated sealing and unsealing

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