A pipe string for fracturing and completing a horizontal well and a fracturing construction method thereof

Abstract

The invention provides a string for horizontal well fracturing completion. The string is characterized by comprising a hydraulic ground control device, a bushing, an oil pipe arranged inside the bushing, a hydraulic line, a hanger, a plurality of fracturing construction units and a seat sealing unit at the bottom end of the string. The fracturing construction units are sequentially connected with the oil pipe in a horizontal section, and each fracturing construction unit is provided with a hydraulic packer and a hydraulic slide bushing. One end of the hydraulic line is connected with the hydraulic ground control device, and the other end thereof is connected with the hydraulic packer and the hydraulic slide bushing of each fracturing construction unit. The hydraulic ground control device provides hydraulic pressure serving as pressure change of control signals to the hydraulic slide bushings through the hydraulic line so as to open or close each hydraulic slide bushing. The invention further provides a fracturing construction method for horizontal well fracturing completion. The string is capable of achieving unlimited staged fracturing of the horizontal section without step-by-step ball feeding as well as achieving later-period staged production, thereby being extremely suitable for offshore staged fracturing.

Description

technical field [0001] The invention relates to equipment for oil and gas field development, in particular to a pipe string for fracturing and completing a horizontal well and a fracturing construction method thereof. Background technique [0002] The low-permeability reservoirs in offshore oilfields are rich in reserves, and the current recovery level is low. There is an urgent need for horizontal well staged fracturing technology. However, due to offshore oilfield production operations, horizontal well staged fracturing technology must have very high reliability. Due to the high operating cost and small platform area of ​​offshore oilfields, staged fracturing of horizontal wells in offshore oilfields has not been carried out in China so far. [0003] At present, there are more than ten kinds of staged fracturing technologies for horizontal wells in domestic and foreign oilfields, among which three are the most widely used technologies, which are packer-sliding sleeve stage...

AI Technical Summary

Problems solved by technology

The technology has the following problems in field application: (1) In the open hole section, the packer cannot guarantee complete sealing under high pressure, which will affect the segmentation effect; (2) The number of fracturing stages is limited by the use of step-by-step ball setting. ;(3) The quality of the borehole is high, and the drilling time is long. Generally, 4-5 well drillings are required after drilling, but there are still risks of drill sticking and failure of the pipe string to run in place.

(4) Fractures may occur in the well section between the two packers, and the location of the fractures is uncontrollable

The hydraulic sandblasting perforating technology has the following limitations: (1) the displacement is limited, the fracturing scale is small, and it is difficult to form long fractures and network fractures; (2) the nozzle is easy to wear, which limits the number of fracturing stages; (3) it cannot Realize post-selective production

[0007] From the above analysis, it can be seen that the above staged fracturing technologies are difficult to meet the requirements of high reliability and later stage selective production in offshore oilfields, and there is an urgent need for a short construction time, unlimited number of fracturing stages, which can achieve selectivity. Production horizontal well staged fracturing technology

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