RU2182651C1 - Process of completion of well - Google Patents

Abstract

FIELD: oil industry, construction and completion of wells. SUBSTANCE: well is equipped with casing string sunk to roof of productive pool and open shaft into productive pool drilled from cased well. Open shaft is expanded in zones of oil-bearing interlayers and is simultaneously washed with oil. After this expanded shaft of well is machined by hydraulic jet of acidic solution through nozzle meant for hydraulic-and-sand jet perforation. EFFECT: raised productivity of well.

Description

 The invention relates to the oil industry and may find application in the construction and completion of the well.

 A known method of well completion, including the implementation of an open wellbore (Akulshin A.I. and others. The operation of oil and gas wells. - M .: Nedra, 1989, p. 86.87).

 The disadvantage of this method is the impossibility of selective exposure to each interval of the thickness of the reservoir and increase productivity of the well.

 Closest to the invention in technical essence is a method of well completion, which includes supplying the well with a casing to the top of the producing formation and drilling an open hole into the producing formation from a cased well (RF Patent 2165516, publ. 04/20/2001 - prototype).

 The disadvantage of this method is the low productivity of the well after its commissioning.

 The invention solves the problem of increasing well productivity.

 The problem is solved in that in the method of completing a well, including supplying the well with a casing to the top of the producing formation and drilling an open hole into the producing formation from a cased well, according to the invention, oil-saturated interlayers are determined in the well, the open well is expanded in the zones of oil-saturated interlayers and simultaneously washed with oil and then the expanded borehole is treated with a hydro-jet supply of an acid solution through a nozzle for hydro-sandblasting perforation.

SUMMARY OF THE INVENTION
When completing a well in a reservoir with a strong reservoir material, the bottom of the well is left without a casing. However, different intervals of the reservoir have different permeability. In this regard, it is advisable to selectively affect each interval of the reservoir to increase well productivity. The proposed method solves the problem of increasing well productivity due to the selective effect on each interval of the thickness of the reservoir. The problem is solved by the following set of operations.

 Drill a well to the top of the reservoir with a casing, for example, 146 or 168 mm in diameter. The annular space is cemented. An open hole is drilled from a well cased in this way into the reservoir. Before the expansion of the well, the depth and thickness of the oil-saturated layers are determined, for example, by means of geophysical studies. Expand the open wellbore in the zones of oil-saturated layers and at the same time washed with oil. Expansion of the open wellbore is carried out by a sliding expander, for example, the PP-146 or PP-168 model, which allows to increase the diameter of the well up to 300 and more mm.

 The expansion of the open hole leads to an increase in the filtration area and an increase in the flow rate of the well. In some interlayers, for example, non-reservoir interlayers, it is irrational to expand the open trunk.

 To increase the production rate of the well, the extended wellbore is additionally treated by hydro-jet supply of an acid solution through a nozzle for hydro-sandblasting perforation with a diameter of 4-6 mm. The acid solution is pumped with a jet exit velocity of about 100 m / s from the nozzle.

An example of a specific implementation of the method
An oil producing well is drilled 1000 m deep to the top of the reservoir, a well is cased with a diameter of 168 mm to the top of the reservoir and the annulus is cemented. An open hole with a diameter of 125 mm is drilled from a well cased in this way into the reservoir, the entire thickness of the reservoir is 12 m. Geophysical studies determine the depth and thickness of the layers. It is established that two oil-saturated interlayers with a thickness of 3 m are located in the upper part of the formation with a dense carbonate bridge between them of 2 m. The open hole in the oil-saturated interlayers is expanded to a diameter of 300 mm and the well is washed with oil. After washing the well with oil, the expanded wellbore is treated with a hydro-jet feed of a 12% aqueous hydrochloric acid solution through a 6 mm diameter hydro-sand perforation nozzle. The acid solution is pumped through a cementing unit CA-320 with a jet exit speed of the nozzle of the order of 100 m / s. As a result, the flow rate of the well increased by 20%.

 The application of the proposed method will increase the productivity of the well.

Claims (1)

 A method of completing a well, comprising supplying the well with a casing to the top of the producing formation and drilling an open hole into the producing formation from a cased well, characterized in that oil-saturated interlayers are determined in the well, the open well is expanded in the zones of oil-saturated interlayers, and at the same time it is washed with oil and then treated extended wellbore by hydro-jet supply of acid solution through a nozzle for hydro-sandblasting perforation.