Side-tracking slim hole layered fracturing string and side-tracking slim hole layered fracturing method

Abstract

The invention provides a side-tracking slim hole layered fracturing string which comprises a sleeve, a first oil pipe, a tubing anchor, a fracturing plug and a tail string, wherein the first oil pipe, the tubing anchor, the fracturing plug and the tail string are arranged in the sleeve and are sequentially connected from top to bottom; the sleeve is provided with a flank hole; the upper end of the tail string is connected with the fracturing plug, and the lower end of the tail string passes through the flank hole; the tail string consists of a hanger, a second oil pipe, a ball seat, a third oil pipe, a soluble porous pipe, a fourth oil pipe and a tail pipe shoe which are sequentially connected from top to bottom; the hanger is connected with the fracturing plug. The invention also provides a fracturing method. A fracturing tool is not needed to be fed, not only can the large-displacement fracturing construction requirement be met, but also downhole tool feeding risks can be avoided, and meanwhile perforating operation at a lower reservoir stratum is omitted; compared with a well cementation sliding sleeve layered fracturing method, the risk that the sliding sleeve cannot be opened is avoided, furthermore, the side-tracking slim hole layered fracturing method has the characteristics that the blank of layered fracturing technology in feeding tail strings with an inner diameter of 76mm into a slim hole with an inner diameter of 118mm and cementing the well by using cement is filled.

Description

technical field [0001] The invention belongs to the technical field of layered fracturing of oil and gas wells, and in particular relates to a sidetracking slim hole layered fracturing string and a method. Background technique [0002] At present, most major oil fields at home and abroad have entered the middle and late stages of development, and the production capacity of oil and gas wells decays rapidly. When the production is too low, they no longer have the value of exploitation. In order to save costs, the technology of drilling slim holes inside old wells has been developed rapidly, especially in offshore platforms and mountain oilfields. Sidetracking of old wells not only avoids costly well site construction, but also reduces pipeline network construction and environmental pollution. This is of great significance to today's oil and gas field enterprises with the theme of energy conservation and environmental protection. For the larger original wellbore, the sidetrack...

AI Technical Summary

Problems solved by technology

Another possible method for slim hole layered fracturing is hydraulic jet layered fracturing. The oil casing injection method can appropriately increase the fracturing displacement. However, the minimum outer diameter of the injector is Φ80mm at present, and Φ70mm is not seen. Application reports for the following injectors

There is another possible method for layered fracturing of slim holes is to use cementing sleeves for layered fracturing. This method has been used in several wells in conventional wells, but the failure rate is quite high. Sliding sleeve fracturing in layers may have a higher failure rate, so far no field application has been seen

Other slim hole layered fracturing methods such as current limiting method and temporary plugging method are not effective isolation layering techniques, the layering is unreliable, and the fracturing stimulation is not thorough

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