RU2087694C1 - Method of treating bottom-hole zone of reservoir - Google Patents

Abstract

FIELD: oil and gas production industry. SUBSTANCE: this is applied for intensifying oil and gas production, improving safety of operation at application of explosives, increasing service life of undersurface equipment of well. For this purpose, explosive agent for treatment of reservoir is produced directly in production reservoir, and blast is initiated by hydraulic impacts. EFFECT: high efficiency.

Description

 The invention relates to the oil and gas industry and can be used to intensify oil and gas production, as well as in well development.

 A known method of influencing the bottom-hole zone of the formation, based on the impact on the formation of shock waves by detonation of explosives (BB) obtained in the wellbore at its bottom.

 However, the known method has several significant disadvantages: low processing efficiency due to the limitation of the volume of explosives used, the destruction of the casing string and cement ring, etc.

 The aim of the invention is to increase the efficiency of processing the bottom-hole zone of the formation, increasing the safety of operations when using explosives, increasing the life of the underground equipment of the well.

 This goal is achieved by the fact that in the method of impact on the bottom-hole zone, including the creation of shock waves by sequential injection into the formation of chemicals that form when the explosive is displaced, followed by the initiation of an explosion, the chemicals used are those that are highly sensitive to water hammer explosives, while the initiation of the explosion is carried out by hydroblows.

 The proposed method is implemented as follows.

 Tubing with a packer is lowered into the well. By installing the packer, the bottom-hole zone is separated from the annulus.

 Then, through the tubing, sequential injection of the chemicals necessary to produce explosives is performed.

 Following this, the calculated amount of the squeezing fluid is required to be injected to sell the reagents at any distance from the wellbore. When selling pumped reagents are mixed in the pore channels and reservoir fractures. When they are displaced, a reaction occurs, as a result of which an explosive is formed.

 The initiation of the obtained explosive is carried out by one of the known methods, for example by hydroblow, using the high sensitivity of the obtained explosive.

 The ability to obtain the required amount of explosives in the formation rock at a calculated distance from the wellbore allows you to create explosions of the required power in the formation rock at any distance from the wellbore.

 The use of liquid explosives such as nitroesters, nitro alcohols, etc. is proposed as an explosive. resulting from the esterification reaction.

 As an example, the calculation of the production and use of high sensitivity nitroglycerin BB is proposed.

Initial data:
Casing Diameter 5 "
Diameter of tubing 2/2 "
Formation perforation interval 995-998 m (3 m)
Porosity 0.3
Removal of the center of the explosion from the wellbore 2 m
As explosives take nitroglycerin
CH ₂ ONO ₂ -CHO NO ₂ -CH ₂ ON ₂
Heat of Explosion 1500 kcal / kg
Knock speed 7700 m / s
The volume of gases produced by the explosion 713 l / kg
Estimated requirement of explosive nitroglycerin 113.5 kg
To obtain nitroglycerin carry out the esterification of glycerol
CH ₂ OH-CHOH-CH ₂ OH + 3HNO ₃ = CH ₂ ONO ₂ -CHONO ₂ -CH ₂ ON ₂ + 3H ₂ O
For the reaction, concentrated nitric acid is used in the presence of concentrated sulfuric acid.

 The required amount of chemical reagents is determined.

 The calculation of the reagents is as follows, mol.m.

Glycerin 92
Nitric acid 63
Nitroglycerin 227
Sulfuric acid 98
Thus, to obtain one gmol of nitroglycerin (227 g), one gmol of glycerol (92 g), three gmoles of nitric acid (63 • 3,183 g), as well as 189 g of concentrated sulfuric acid are required.

где V объем жидкости, м³;
m пористость в долях единиц;
R глубина закачки реагента в пласт;
h интервал перфорации пласта, м;
d диаметр насосно-компрессорных труб;
H длина насосно-компрессорных труб до нижних отверстий интервала перфорации

Объем продавочной жидкости 14,104 м³.Therefore, to obtain 113.5 kg of glycerol, 94.5 kg of nitric and 94.5 kg of sulfuric acid are required. The total volume of squeezing fluid is determined by the formula

where V is the volume of liquid, m ³ ;
m porosity in fractions of units;
R is the depth of reagent injection into the formation;
h interval perforation of the reservoir, m;
d tubing diameter;
H the length of the tubing to the lower holes of the perforation interval

The volume of the squeezing liquid is 14.104 m ³ .

Thus, in order to produce an explosion in the formation using nitroglycerin at a distance of 2 m from the bottom of the well and obtain the desired effect (i.e., increasing the number of cracks and the radius of their propagation), it is necessary to sequentially pump 46 kg of glycerol into the formation, then a mixture of concentrated nitric and sulfuric acid in a ratio of 1: 1 (94.5 94.5 kg), followed by the sale of these components into the formation by squeezing liquid in a volume of 14.104 m ³ .

 After the reaction time, the creation of water hammers in the well is carried out using known devices and methods, for example downhole hydraulic vibrators, etc.

 Thus, the invention allows to significantly increase the radius of the formation, improving the conditions of oil inflow to the well by expanding existing and creating new fractures in the formation rock, increasing the safety of work by eliminating the operations of transportation, storage and use of explosives, eliminating damage to underground equipment beyond due to the transfer of the center of the explosion from the wellbore into the reservoir.

Claims (1)

 A method of influencing the bottom-hole zone of a formation, including the creation of shock waves by sequentially injecting chemicals into the formation that produce explosive when mixed, followed by the initiation of an explosion, characterized in that the chemicals used are highly explosive sensitive to water hammer explosions this initiation of the explosion is carried out by hydroblows.