RU2135758C1 - Method of treating well bottom zone - Google Patents

Abstract

FIELD: oil and gas production. SUBSTANCE: invention can be used when treating bottom zone of production well or production well converted into injection well. According to invention, casing string is cleaned, distillate is injected into well, and first process pause is performed. Then, 0.5-5% solution of nonionic surfactant in associated Devonian water is injected into well and forced into formation, after which second process pause follows. Additional depression perforation is carried out and casing string is cleaned once more. EFFECT: increased productivity of well.

Description

 The invention relates to the oil industry and can be used in the treatment of the bottom-hole zone of a producing well or a well, transferred to the injection from the producing.

 A known method of processing the bottom-hole zone of the well, including the injection of distillate into the well and technological exposure [1].

 The disadvantage of this method is the low productivity of the wells.

 Closest to the proposed invention in technical essence is a method for processing the bottom-hole zone of a well, including injecting distillate into the well, conducting the first technological exposure, injecting into the well and injecting into the formation a 0.5 - 5% solution of nonionic surfactant in associated Devonian water, conducting a second technological exposure and performing additional perforation [2].

 The disadvantage of this method is the insufficiently high productivity of the wells.

 The invention solves the problem of increasing the productivity of wells.

 The problem is solved in that in a method for processing a bottom-hole zone of a well, including injecting distillate into the well, conducting the first technological exposure, injecting into the well and injecting into the formation a 0.5-5% solution of nonionic surfactant in associated Devonian water, the second technological exposure and the implementation of additional perforation, according to the invention, before the distillate is pumped, the casing is mechanically cleaned, while additional perforation is carried out, depression perforation is carried out then re-clean the casing.

The essential features of the invention are:
1. injection into the well of distillate;
2. conducting the first technological exposure;
3. injection into the well and pushing into the formation of 0.5 - 5% solution of nonionic surfactant in associated Devonian water;
4. carrying out the second technological exposure;
5. performing additional perforation;
6. before the injection of distillate, mechanical cleaning of the casing string;
7. when performing additional perforation, conducting depressive perforation;
8. re-cleaning the casing.

 Signs 1 to 5 are similar to the prototype, signs 6 to 8 are essential distinguishing features of the invention.

SUMMARY OF THE INVENTION
During the operation of the wells, mudding of the bottomhole zone occurs and the productivity of the well decreases. The invention solves the problem by increasing the bottomhole zone to increase well productivity.

 Injecting distillate basically allows you to dissolve paraffin deposits, and injecting an aqueous solution of a surfactant apparently allows you to influence the consequences of drilling fluids. However, without distillate washing and allowing the penetration of the surfactant solution into the formation, it is not possible to conduct a successful treatment. The possibility of penetration of a surfactant solution into the formation is provided by depressive perforation. This ensures simultaneous cleaning of the perforation holes due to the instant depression that occurs after perforation and the extraction and retention of contaminants in the depression chamber. The use of mechanical cleaning of the casing string before the distillate is injected into the well and after perforation improves the quality of cleaning not only in the bottomhole zone, but also in the well design itself. Mechanical cleaning is carried out during tripping operations of the tubing string, on which scrapers are fixed on the outer surface in the form of wire brushes, etc.

The distillate is a mixture of saturated hydrocarbons with the number of carbon atoms 7 - 10. The distillate is a flammable, water-insoluble dark brown liquid with a density of 815 kg / m ³ , with a flash point of 30 ^o C.

Concrete example
Example 1. A production well with a depth of 17,215 m, crossing the reservoir with a terrigenous reservoir, was inactive, its flow rate was zero. It was not possible to revive the well by any means of treating the bottom-hole zone, i.e., to cause inflow. A tubing string with wire ruffs on the outer surface is lowered into the well and the surface of the casing is treated. 25 m ^{3 of} distillate is pumped into the well. Carry out technological exposure for 24 hours. A 3% solution of non-ionic surfactant OP-10 in associated Devonian water with a density of 1.07 g / cm ³ in a volume of 15 m ^{3 is} pumped and pushed into the well into the well. Spend technological exposure for 8 hours. A cumulative perforator with a depression chamber is lowered to the bottom of the well and perforation is carried out in the existing perforation interval. Raise the tubing string with wire brushes. The well is put into operation. The well production rate after processing amounted to 22 tons of oil per day.

 The application of the proposed method will allow to develop previously undeveloped wells and increase oil production in the deposits.

Sources of information taken into account when preparing the application:
1. Bakirov A.U. and other Chemical methods in the processes of oil production.-M: Nauka, 1987, p. 18-19.

 2. RF patent N 2060369, 1996 - a prototype.

Claims (1)

 A method of processing a bottomhole zone of a well, including injecting distillate into the well, conducting the first technological exposure, injecting into the well and injecting into the formation a 0.5-5% solution of nonionic surfactant in associated Devonian water, conducting a second technological exposure and performing additional perforations, characterized in that prior to the injection of the distillate, the casing is mechanically cleaned, while additional perforation is performed, depression perforation is carried out, and then repeated casing string cleaning.