Horizontal well machinery staged fracturing tool stringTechnical field:
The present invention relates to oil recovery field, oil field used downhole tool, especially horizontal well machinery staged fracturing tool string.
Background technology:
Fractured horizontal well has great importance to the volume increase transformation of low-permeability oil deposit, but because the horizontal well casing programme exists inclination section and horizontal segment, fracturing string and stressed and sand setting situation and straight well differ greatly, and the use of conventional fracturing tool is restricted.Existing fracturing tool string can only descend the straight well section, there is the restive shortcoming in crack in the general limited entry fracture treatment of carrying out horizontal well, in order to strengthen the specific aim of pressure break, raising has been studied horizontal well minor diameter staged fracturing technology to the control degree in fractured horizontal well crack.
Summary of the invention:
The purpose of this invention is to provide a kind of horizontal well machinery staged fracturing tool string that can be used for realizing the horizontal well in segments pressure break.
Technical scheme of the present invention is: this horizontal well machinery staged fracturing tool string comprises oil pipe, sleeve pipe, and oil pipe places in the sleeve pipe, and the oil pipe lower end is attachment security joint, centralizer, packer, pilot sandblaster, packer, guiding plug successively.
An oil pipe is arranged between centralizer and the packer.Left side packer is connected with oil pipe with the pilot sandblaster.Packer is an expansion type K344 type.The external diameter of safety joint is φ 95mm, and internal diameter is φ 48mm.
The present invention has following beneficial effect: utilize packer and the kit can be to desiring processing layer position fragment-force, the chock pressure difference by the pilot sandblaster sets the pressure break packer, takes the mode put forward, and one-trip string can be finished the pressure break of each interval.Pilot sandblaster sand jet outlet is short apart from right packing element end face distance, has reduced the sand setting of packer upper end, has improved the security performance of fracturing technology.This tool string is simple in structure, and the packer lower end is a movable end, and its pressure-bearing height is implemented the segmentation transformation for horizontal well means are provided.
Description of drawings:
Accompanying drawing 1 is a structural representation of the present invention.
Form by safety joint 1, centralizer 2, packer 3, pilot sandblaster 4, guiding plug 5, oil pipe 6, sleeve pipe 7 among the figure.
The specific embodiment:
The invention will be further described below in conjunction with accompanying drawing:
By shown in Figure 1, this horizontal well machinery staged fracturing tool string comprises oil pipe 6, sleeve pipe 7, and oil pipe 6 places in the sleeve pipe 7, and oil pipe 6 lower ends are attachment security joint 1, centralizer 2, packer 3, pilot sandblaster 4, packer 3, guiding plug 5 successively.
An oil pipe 6 is arranged between centralizer 2 and the packer 3.Left side packer 3 is connected with pilot sandblaster 4 usefulness oil pipes.Packer 3 is an expansion type K344 type.The external diameter of safety joint 1 is φ 95mm, and internal diameter is φ 48mm.
Because the external diameter of safety joint 1 is φ 95mm, internal diameter is φ 48mm, after the pressure break in case on carry load than the kilocalorie tubing string, the steel ball that well head is thrown φ 52mm builds the pressure and opens inner sliding sleeve, safety joint 1 upper and lower joint is separated, thereby trip out top oil pipe 6.Centralizer 2 makes this tool string placed in the middle in playing the lower tubular column process, prevents that packer 3 is impaired, at horizontal segment packer 3 is better set between two parties.Packer 3 has the above sleeve pipe of protection target zone, the effect of separating oil reservoir.Pilot sandblaster 4 can produce chock pressure difference sets its left and right sides packer 3 simultaneously, also is the passage that fracturing fluid enters target zone simultaneously, also can be used as the anti-flushing well passage when the sand card, removes in the process at tubing string, and guiding plug 6 plays the effect of guiding.
During site operation, in oil pipe 6 carries under this tool string sleeve pipe 7 behind the precalculated position, seated well head, ground fluid injection then, pilot sandblaster 4 produces chock pressure difference sets left and right sides packer 3, realize separating the purpose of oil layer section, fracturing fluid enters into the stratum through the side opening of pilot sandblaster 4, presses off the stratum.Upper lifting pipe post behind the intact interval of pressure break makes this tool string advance to another interval and carries out pressure break, and one-trip string just can be finished the pressure break of each interval like this.