Old well repeats transformation coiled tubing controllable confining process pipe stringTechnical field
The present invention relates to a kind of old well and repeat transformation coiled tubing controllable confining process pipe string, belong to oil-gas field fracturing technical field.
Background technology
After low-permeability oil gas well pressure break completion produces a period of time, fracture condudtiviy declines gradually.In order to improve single well productivity, excavating Oil/gas Well productive potentialities, often will re-start pressure break.Different from new well pressure break, concerning many old wells again pressure break, after tripping out original production tubing string, there is well control risk with boring under conventional oil pipe, need be with and depress into fracturing reform drilling tool, therefore, coiled tubing dragging with pressure can be utilized to solve.In addition, in old well refracturing process, because crack, upper strata is opened, so upper and lower layer packing will be considered simultaneously.
Summary of the invention
A kind of old well is the object of the present invention is to provide to repeat transformation coiled tubing controllable confining process pipe string, to carry out the old well layering refracturing transformation of the larger straight well of well control risk, directional well and horizontal well.
Concrete technology contents of the present invention is as follows:
The coiled tubing of this process pipe string connects shearing by connector and gives up, shearing lower end of giving up connects mechanical type casing collar locator (CCL), mechanical casing collar locator lower end connects controllable confining, controllable confining lower end connects ejector, ejector lower end connects lower packet, lower packet lower end connects sleeve base, and sleeve base lower end connects guiding check valve.
This process pipe string is when coiled tubing abrasive perforating, and annular space liquid outlet channel is unimpeded, can guarantee perforating effect.When pressure break, the reliable upper and lower transformation layer of packing of energy, guarantees fracturing effect.This process pipe string completes multistage perforation by coiled tubing dragging with pressure is disposable, utilizes two envelope single deck tape-recorder packing mode from coiled tubing sand fracturing, completes a point interval transformation successively, realize perforating and fracturing integration, improve the efficiency of construction of old well refracturing.
Accompanying drawing explanation
Fig. 1 is that old well repeats transformation coiled tubing controllable confining process pipe string schematic diagram.
Fig. 2 is the operating diagram of old well when repeating transformation coiled tubing controllable confining process pipe string perforation.
Fig. 3 is that old well repeats transformation coiled tubing controllable confining process pipe string unset state schematic diagram.
Fig. 4 is that old well repeats transformation coiled tubing controllable confining process pipe string and sets view.
Detailed description of the invention
Embodiment:
Further illustrate referring to figs. 1 through 4 pairs of embodiments of the invention:
The coiled tubing 1 of this process pipe string connects shearing by connector 2 and gives up 3, shearing 3 lower ends of giving up connect mechanical type casing collar locator (CCL)s 4, mechanical casing collar locator 4 lower end connects controllable confining 5, controllable confining 5 lower end connects ejector 7, ejector 7 lower end connects lower packet 8, lower packet 8 lower end connects sleeve base 9, and sleeve base 9 lower end connects guiding check valve 10.
The fracturing process of this process pipe string is as follows:
1), after tripping out flow string, lower coiled tubing leads to Flushing tubular column, completes through wash well operations.
2) enter this process pipe string under, located by casing collar locator (CCL) 4, ejector 7 is aimed at first paragraph design improvement position, inject perforating fluid from coiled tubing 1.When perforating fluid is apart from nozzle 200m, improves discharge capacity, carry out first paragraph hydraulic jet perforation.During perforation, lower packet 8 is in the state of setting, and controllable confining 5 inlet opening, by sliding sleeve 6 shutoff, is in unset state all the time, and perforating fluid returns out from oil jacket annular space.
3) carry coiled tubing 1 on, complete the hydraulic jet perforation of all the other intervals one by one.
4) lower coiled tubing 1 after perforation, aims at first paragraph design improvement position, throws the steel ball of φ 19.05mm from coiled tubing 1.Treat that steel ball drops on sliding sleeve 6, coiled tubing 1 adds hydraulic pressure, shears the connection pin between controllable confining 5 and sliding sleeve 6, and sliding sleeve 6 and steel ball together drop down onto on sleeve base 9, and now, controllable confining 5 can normally set.After nozzle crosses liquid generation chock pressure difference, controllable confining 5 and lower packet 8 are all in the state of setting, the upper and lower layer of packing.Then, inject fracturing fluid to coiled tubing 1, complete first paragraph pressing crack construction.
5) carry coiled tubing 1 on, complete the pressing crack construction of all the other intervals one by one.
6) this process pipe string is tripped out, lower flow string, completion.