SU920008A1 - Composition for preventing deposition of salt - Google Patents

Description

(54) COMPOSITION FOR PREVENTION OF SALT DISTRIBUTIONS.

The invention relates to methods for preventing the formation of deposits of sparingly soluble salts and can be used in the operation of oilfield equipment.

In many cases, the operation of oil wells is complicated by the formation of deposits of sparingly soluble salts (sulfates and carbonates of alkaline earth metals, iron hydroxide, etc.) in oilfield equipment (on the walls of pipes, in submersible pumps, etc.). As a result, the well rate gradually decreases, the equipment goes out of operation. Removing a thick, saline layer from the surface of the equipment is expensive.

The most effective way to control salt deposits is to prevent their formation by means of sediment inhibiting chemical reagents, which, with a small consumption for a long time, prevent the formation of salt deposits.

As inhibitors of scaling use polyphosphates 11, phosphonic acids 2 and various compositions based on them.

A known composition for preventing the formation of scaling, in particular in oilfield equipment, includes,%: polyethylenepolyamine-N-methylphosphonic acid salt deposition inhibitor or its salt 10-30; HjPOi 1-10 HCL 10-15; NSON 1-10 and water C31.

However, the known composition is impossible

10 to use in conditions of low. temperatures. At temperatures below minus 30-35 ° C, the composition freezes or becomes so viscous that its application is almost impossible.

15

The purpose of the invention is to increase the degree of prevention of salt deposits at low temperatures.

The goal is achieved by the addition of ethylene glycol in the composition containing polyethylenepolyamine 20 -N-methylphosphoric acid or its salt and water, in the following ratio of components, wt.%:

Polymethylene polyamine 25

-N-methylphosphonic

acid or its salt 5-12

Ethylene glycol 30-50

WaterEverything

Application of the proposed composition

30 can be implemented using

well-known technological methods and equipment: in the case of the exploitation of oil wells by the method of periodic injection of the inhibitor into the bottomhole formation zone of the well and by the method of constant dosing into the annulus of the well. Components LIIZI. Polyethylenpolyamine-methylphosphonic acid, sodium salt 25 12.5 10.0 8.5 7 Ethylene gly25 37 37.50 35 col- Water 75 62.5 53 49 58

Then solutions thermostat lot at d t control experiment without the addition of pe75 С. After 6. h, the containing agent is determined.

calcium and magnesium ions in solution; 30 Degree of inhibitory effect. . For comparison, parallel to the wire composition is presented in Table 2, Composition (based on the active principle)

10 .1 20 30 I 50

172 64 64 41

270 63 64 47

375 66 66 43

From the results shown, the freezing temperature of the compositions that the proposed compositions possess is determined according to GOST 1533-42, and its sound efficiency, while preventing the reotest from the calibration of carbonate deposits, with a calorific curve, built according to the station, with the greatest effective 5.0 solutions with known viscosity (75%) at a flow rate of 10 mg / volume. The results of the experiments have a composition of 4. presented in so-called.

TemperatureViscosity, P10 at temperature Composition of freezing ,, tour, С

. LifEIIZr iiriifil

-35 -37

-52

The degree of prevention of salt deposits is determined as follows.

In a series of 250 ml flasks, 100 ml of produced water of ionic composition, mg / l are added: Sa VOO; HCOi 876; Na .500; C 14047 and add inhibitory composition. Data on the composition are given in table.1.

Table 1 Content

Table 2

Reagent consumption, mg / l

Table 3

1300.2 151.3

Claims (3)

655.4 345.6 wt.% Lirnril. 6.7 5.7 12.5 6.3 41.7 50 37.0 55.0 51.6 44.3 50.5 38.7 From the data presented it is clear that the known composition 1 freezes at, but already at its viscosity reaches 1300.2 P10. With viscosities above 1000 P 10, it becomes impossible to dose them with dosing pumps. With an increase in the content of polyethylene enpolyamine-K-methylphosphonic acid or its salt over 12%, and ethylene glycol over 50%, the viscosity of the mixture sharply increases. When the ethylene glycol content is less than 30%, the freezing temperature of the solution increases significantly. The reduction of active principle below 5% is uneconomical, as it leads to high costs when dosing the composition. Of the proposed formulations, composition 4 has the lowest freezing point at low viscosity, and has the highest inhibitory ability. The use of this composition makes it possible to effectively prevent the sedimentation of sparingly soluble salts, in particular, in oilfield equipment, under conditions of negative temperatures. The proposed composition is the continuation of the table 3. It has a high inhibitory capacity at low dosages (10 mg / l). Formula of the invention Composition for the prevention of scaling, including polyethylene polyamine-N-methyl phosphonic acid or its salt and water, is the degree of prevention of salt deposits in conditions of low temperatures, it additionally contains ethylene glycol in the following ratio, wt.% Polyethylenepolyamine-N-methylphosphonic acid or its salt 5-12 Ethylene glycol30-50 WaterElmost e Sources of information received note in the examination 1.Patent № US 3213017, cl. 252-8.55, publ. 1962. 2. Patent STR 3867286, cl. 210-58, publ. 1975. 3. Authors certificate of the USSR 646035, cl. E 21B 43/00, 1979 (prototype).