Background technology
Low-permeability oil deposit has that reservoir buried depth is big, formation temperature is high, reservoir properties are poor, permeability is little, and different interlayer thingsThe features such as sex differernce is larger.At present, waterflooding development is a kind of technology of important exploitation low-permeability oil deposit.As oil field development is enteredEnter ultra-high water-containing development period, interlayer contradiction is more projected, seperated layer water injection is realized in layer, interlayer equilibrium displacement is to improve waterflooding extractionThe important measures of effect.
At present conventional water injection technology is suspension type separate zone waterflooding technology, conventional to hang tubing string in use, due to tubing stringOverall force unbalance, tubing string is integrally by a upper top power, and lower floor's water injection pressure is higher, and thereon top power is bigger, serious shadowRing seperated layer water injection effect duration；Meanwhile, separate injection tubing string water filling, well-flushing, it is dynamic stop during interlayer pressure difference, temperature change when, down-holeTubing string occurs flexible, easily causes tubing string and packer wrigglings, local creep, expands, and tubing string stretches caused end tear failureCharacter substantially, easily causes packer sealing failure.
Utility model content
For the above-mentioned technical problem in the presence of prior art, the utility model proposes a kind of brace type water injection pipePost.By brace type water injection string of the present utility model, can effectively prevent tubing string, packer from wriggling, extend the use of sealerIn the life-span, improve flood effectiveness.
To solve above-mentioned technical problem, brace type water injection string of the present utility model, including oil pipe, the water injection string is also wrappedInclude compensator, joint, at least one first water injection units, slips and the second water injection unit being sequentially connected；The compensator oneEnd is connected with oil pipe, and the other end is connected with the joint；Wherein, first water injection unit by the first injection well downhole flow regulator, centralizer andPacker is connected in sequence, and second water injection unit is connected in sequence by the second injection well downhole flow regulator and flushing valve.
Used as a kind of improvement of the present utility model, the joint is left-hand tool joint.
The packer is compressive washable well packet or the closed packer of expanding.
Used as another improvement of the present utility model, first injection well downhole flow regulator is rail mounted injection well downhole flow regulator.
Second injection well downhole flow regulator is rail mounted injection well downhole flow regulator.
The flushing valve is level pressure sand-sinking well flushing valve.
The slips is hydraulic slip.
Compared with prior art, the utility model has the advantage of：Tubing string is can compensate for by the setting of compensator to stretch,Packer is avoided to wriggle up and down with tubing string, so as to effectively improve the seal pressure and service life of packer；Meanwhile, by level pressureSand-sinking well flushing valve realizes constant pressure turn on, effectively prevents packer midway from setting and valve ball is buried；Additionally, passing through left-hand tool jointUse, be easy in lift pipe string operation segment processing, salvage step by step, reduce the risk of upper overhaul during lift pipe string operation；Pass throughHydraulic slip is set, and realize carries out lower support to tubing string, overcomes string creep.
Specific embodiment
Relevant detailed description of the present utility model and technology contents, coordinate description of the drawings as follows, but accompanying drawing only provides ginsengExamine and purposes of discussion, not for being any limitation as to this utility model.
Fig. 1 is illustrated that the water injection string schematic diagram containing first water injection unit, as shown in Figure 1：The brace type noteWater pipe post, is connected in sequence by oil pipe 9, compensator 1, joint 2, the first water injection unit, the water injection unit of slips 6 and second, theOne water injection unit is connected in sequence by the first injection well downhole flow regulator 3, centralizer 4 and packer 5, and the second water injection unit is by the second injection well downhole flow regulator7 and flushing valve 8 be connected in sequence；The upper end of compensator 1 is connected with the lower end of oil pipe 9, and the lower end of compensator 1 is connected with joint 2；Joint 2 links together compensator 1 with the first injection well downhole flow regulator 3 of the first water injection unit, and the packer 5 of the first water injection unit passes throughSlips 6 is connected with the second injection well downhole flow regulator 7 of the second water injection unit.
In a preferred embodiment, joint 2 is left-hand tool joint, is easy in lift pipe string operation segment processing, salvages step by step,Reduce the risk of upper overhaul during lift pipe string operation.Packer 5 can be compressive washable well packet or the closed packing of expandingDevice；In a further preferred embodiment, the first injection well downhole flow regulator 3 can be rail mounted injection well downhole flow regulator, and the second injection well downhole flow regulator 7 is alternatively rail mounted and matches somebody with somebodyHydrophone, rail mounted injection well downhole flow regulator operation principle is：When suppressing from oil pipe 9, the piston of rail mounted injection well downhole flow regulator can be in hydraulic actionThe lower top dead-centre into short track, when 9 release of oil pipe, the piston of track injection well downhole flow regulator can be changed under spring force along trackTo；Afterwards, when needing water filling, water filling gate is opened, the piston of track injection well downhole flow regulator is moved on the long track of water injection pressure lower edge, is openedWaterflood path, so as to smoothly realize water filling.Flushing valve 8 can be level pressure sand-sinking well flushing valve.Slips 6 can be hydraulic slip.
Shown in Fig. 1 is only the water injection string schematic diagram containing first water injection unit, in other embodiments, can rootAccording to it is required separation oil reservoir number, arrange varying number the first water injection unit, the first water injection unit quantity=required separation oil reservoir number-1, it is sequentially connected between each first water injection unit, the bottom after each first water injection unit connection is connected with slips 6, most goes upEnd is connected with joint 2.
During field conduct, master operation is：
1st, assemble, go into the well：First according to required separation oil reservoir number, the quantity of the first water injection unit is selected, by each first noteWater unit is sequentially connected.Then, compensator 1, joint 2, the first water injection unit, the water injection unit of slips 6 and second are sequentially connectedIt is good, the tubing string for connecting is connected with oil pipe 9 afterwards, by entering under engineering design requirements in sleeve pipe 10.
2nd, set：Enter under tubing string after projected depth, suppress from oil pipe 9, when certain pressure is reached, slips 6 is in hydraulic pressureStrut under effect, water injection string supports grappling by slips 6.Packer 5 sets under hydraulic action.Afterwards, the release of oil pipe 9, envelopeSealing state is remained in that every device 5, completes to set.
3rd, inject：Water filling gate is opened, the first injection well downhole flow regulator 3, the second injection well downhole flow regulator 7 open waterflood path under water injection pressure,Smoothly realize water filling.Injection water enters corresponding water filling interval, and water injection rate is controlled by the water nozzle on water distributor core.Compensator 1In free retracted position, the length change that string creep causes is can compensate for, it is ensured that the position of packer 5 maintains static, so as toImprove the stress of packer 5, improve the working life of packer 5.
4th, well-flushing：Flushing fluid is entered from oil jacket annular space, and when certain pressure is reached, packer 5 is unsealed, and flushing fluid enters envelopeEvery device 5 with lower floor position, backwash passage is opened, and injection water will be returned out from oil pipe 9, and reached along this passage, Jing bottoms flushing valve 8The purpose of cleaning oil reservoir and tubing string.Well-flushing completes to proceed to after normal water filling, the restting under hydraulic action of packer 5, realizesEffectively separate oil reservoir in injection process.
Preferred embodiment of the present utility model is the foregoing is only, is not used to limit the scope of the claims of the present utility model, itsHe all should all belong to the scope of the claims of the present utility model with the equivalence changes of patent spirit of the present utility model.