In order to improve the production effect of the new well and break through the bottleneck of the traditional technology, our company has carried out the research work of the non-drilling plug-free graded cement completion technology project, which has been continuously investigated and demonstrated. A new idea of non-drilling plug-free graded cement injection without inner pipe and drillable completion technology without changing the existing cementing technology is put forward. In the drilling process, the down completion string, the bulging pipe outer Packer and the cement injection channel are used in the drilling process, and the cement injection channel is opened by using the downhole completion string, the bulging outer Packer and the cement injection channel. The implementation steps of cementing, closing the cement injection channel and fishing the drilling-free assembly can successfully complete the well. Avoid damage to string and cement sheath caused by drilling plug and well washing at the same time.
The successful development and application of this technology project fills in the gap of domestic technology, solves some defects of existing completion tools, and at the same time improves the level of completion technology, which plays an active role in promoting the continuous and stable production and high production of all oilfields.
Technical characteristics:
Replace drilling with fishing to reduce the development cost and shorten the operation cycle.
Avoid pipe string and cement sheath damage caused by drilling plug and well washing.
The inner diameter of the whole drill-free device and the external Packer is equal to the inner diameter of the casing, forming a large diameter.
Working principle:
The blind plate device goes down to the design position with the completion string, and the cement cementing channel of the tool is opened with poor pressure, and the cementing operation is carried out according to the requirements of cementing design. After the cement injection construction, close the plug impact pressure and close the cement cementing passage on the tool. Bad pressure setting, then down into the special fishing tool assembly and out, after the well to complete all the construction.
Structural composition:
Drill-free blind plate device mainly consists of tool main body, closing rubber plug, special fishing barrel, Packer and so on.
Structural characteristics:
First, choose high strength high quality alloy steel, break through the traditional concept, adopt no inner pipe scheme design, and keep compatible with the existing top cementing technology to the maximum extent.
Second, the double-stage Packer adopts a new type of top, double-tube parallel seat sealing mode, which plays the role of double-safety, safe and reliable. The pressure limit of the rubber tube is high, and the expansion ratio is large.
Third, can take the structure design, guaranteed the casing inside the diameter standard, is convenient for the later operation construction. In order to avoid the damage caused by drilling plug construction and possible loosening and unfastening phenomenon, the fishing method is adopted to replace the drilling plug way to complete the casing channel, and at the same time, the completion process is reduced, the construction cycle is shortened, and the service life of the oil well is prolonged. The use of returnable salvage barrel can be successfully removed when the salvage is not successful.
Fourthly, the non-drilling blind plate of horizontal well completion realizes the combination of conventional grading cement injector, blind plate and outer pipe Packer, which reduces the string of completion pipe and improves the structural stability of the string of completion pipe.
5.According to the cement slurry condensation card, solid phase and sand card, wellhead drop card and casing type card, it can prevent the occurrence of all kinds of predicted accidents.
Sixth, special structure design, high safety performance, in the design process to consider a variety of safety measures.
