SU1759848A1 - Reagent for removing fluids from gas and gas condensate wells - Google Patents

Abstract

The reagent of the general formula: l) —HcX6c t () ph wherea-O-o-alkylphenol residue, in which R - represents the radical CsHiT-CioHai. m is the number of moles of propylene oxide, equal to 10-25; p is the number of moles of ethylene oxide, equal to 80-150 and the water stop .; an alkyl phenol reagent for removing liquid from gas and gas condensate wells provides increased removal efficiency of highly mineralized water and gas condensate from wells at elevated temperatures at the wells. 4 tab. -5 ё

Description

The described invention relates to the gas industry, namely, foaming reagents (compositions) for removing liquid — a mixture of saline water and gas condensate — from gas and gas condensate wells using gas energy.

The foam-forming composition Penolift-2, which contains surface-active substances (surfactants), sodium or ammonium alkyl ethoxy sulfates and alpha olefin-sodium-sodium phonates, is already known. The disadvantage of this composition is the absence of foaming properties in highly mineralized water (100-200 g / l) with a gas condensate content of more than 10% by volume.

Also known is the foaming agent Solpen-10, which contains a surfactant — sodium or ammonium alkane ethoxy sulfates and sodium disulfonate dinaphylmethane sodium or ammonium. The disadvantage of this frother is the impossibility of foam formation in water with a salinity of 100–200 g / l with a gas condensate content of more than 20% by volume.

As a prototype, a reagent is selected in which surfactants are used to remove fluid from the gas well wells — block copolymers of propylene oxide and ethylene with the general formula:

SPN 2n + 1.0 (CzNbO) t (C2H40) pH. where n is the number of carbon in the alkyl radical, equal to 5-151

t is the number of moles of propylene oxide, equal to 9-45;

p is the number of moles of ethylene oxide, equal to 30-180.

3

Yu

00

fcu

The block copolymers of the above general formula are synthesized under conditions of anionic polymerization of propylene and ethylene oxides in the presence of potassium hydroxide at elevated temperatures and pressures. As a starting (starting) substance for the preparation of block copolymers, primary fatty alcohols CnH2n + iOH are used, where n is 5-15. The reagent is capable of forming foam with water salinity up to 200 g / l and gas condensate content up to 40% by volume. The disadvantages of this reagent include the low efficiency of fluid removal from wells due to the relatively weak interaction of block copolymer molecules with hydrocarbon gas condensate molecules.

The aim of the invention is to increase the efficiency of removal of highly mineralized water from gas and gas condensate wells with a significant content of gas condensate and an elevated bottomhole temperature.

This goal is achieved due to the fact that the reagent for removing liquid from gas and gas condensate wells contains block copolymers of propylene oxide and ethylene based on alkylphenols of the general formula as a surfactant:

R -OolCjHsOVKiH H

-

where - an alkylphenol residue in which R represents a CeHiT-CioHzi radical;

m is the number of moles of propylene oxide, equal to 10 ... 25;

p is the number of moles of ethylene oxide, equal to 80 ... 150.

with the following proportion of ingredients (in wt.%):

Block copolymers specified

above the general formula 0.2 ... 0.5

Water the rest.

In appearance, block copolymers of propylene and ethylene oxides based on alkylphenols are a paraffin-like solid with a melting point of about 60 ° C.

As a basis, i.e. the starting (starting) material to obtain block copolymers of the general formula given

R-O-OH.

alkylphenols are used /

A distinctive feature of the prototype is the presence of an alkylphenol residue in the molecules of these block copolymers.

-O- ° - .Alkylphenol residue, in which the benzene ring / 3 is present, gives the block copolymers 5 molecules specific hydrophobic properties and enhances the ability to interact with the gas condensate hydrocarbon molecules. As a result, there is an increase in the efficiency of gas and gas condensate wells.

The use of block copolymers of propylene and ethylene oxides based on alkylphenols as an ingredient in reagents 15 (compositions) for removing liquid from gas and gas condensate wells was not found in the analogous reagents.

Alkylphenol residue n Qt

20 is part of the molecules of block copolymers of ethylene and propylene oxides, currently produced by the company Organika-Rokita (Poland). These block copolymers are Rokaphenol No. 8P7 and Rokaphenol No. 25 8P14, which are used in the textile industry and household chemicals.

The chemical name of the block copolymers is Rokaphenol - nonylphenol polyoxyethylene polyoxypropylene glycol, i.e. their

30 molecules have the following chemical formula:

C9H13-O 0 (C2H) p (C3NbO tN,

35 where p is the number of moles of ethylene oxide (equal to 8 for each substance):

m is the number of moles of propylene oxide (equal to 7 for the first substance and 14 for the second substance).

40 Comparison of chemical formulas shows that Rokafenol block copolymers have the following differences from inventive block copolymers:

1) the former are block copolymers 45 of the type REP, while the block copolymers claimed are of the type RPE, i.e. hydroxypropyl and oxysyl blocks are connected in reverse order;

2) the number of moles of ethylene oxide in block-50 polymers of Rokaphenol is fixed and equal to 6, while for filled block copolymers the number of moles of ethylene oxide varies from 80 to 150;

3) the number of moles of propylene oxide in the block copolymers of Rokaphenol is fixed and equal to 7 and 14, respectively, while for the initiated block copolymers the number of moles of propylene oxide varies from 10 to 25.

Thus, the chemical structure and composition of the molecules of the block copolymers Rocaphenol and the block copolymers in question are different, i.e. they are different substances. This difference is confirmed by the measurement of the foam lifetime for the samples of the claimed block copolymers and for the samples of Rotaphenol. The ability to foam is a prerequisite for using a substance as a reagent to remove fluid from wells.

The measurements were performed by the standard method. The results are presented in table. one.

Given in Table. In Figure 1, the data show that the block copolymers (No. 1-3) form a foam, the life time of which is from 125 to 165 minutes. At the same time, Rokaphenol block copolymers do not form foams and, therefore, cannot be used to remove liquids from gas and gas condensate wells.

Thus, in terms of their ability to remove liquid, the block copolymers of the invention are qualitatively different from those of Rokafenol, which allows the conclusion that the proposed technical solution is consistent with the criterion of significant differences.

The conformity of the technical solution with the criterion of positive effect is indicated by the data given below in the section Technical advantages (Table

four).

Specific examples of the block copolymers described in Table 1 cover the minimum (mln) and maximum (max) limits of the numbers of moles of propylene oxide m and ethylene oxide p claimed in the claims:

N 1 - m 10 min, p 80 min;

Ns 2 - m 13, (the best option);

Mz 3 - m 25 max, p 150 max.

In tab. Table 2 shows specific examples of block copolymers that have prohibitive values for the number of moles of oxides (the numbering of the samples continues the numbering of Table 1):

No. 4 - m 8 min, p 85 mln;

No. 5 - m 8 min, p 175 max;

Ms 6 - m 35 max, p 30 min;

Ms 7 - m 35 max p 160 max.

In tab. 2 also provides information on the prototype substance.

Data analysis table. 1 and 2 shows that samples of block copolymers with prohibitive values of the numbers of moles of propylene oxide and ethylene oxide have significantly

Shorter foam lifetimes than samples with claimed limits for the number of moles of oxides. Therefore, block copolymer samples No. 4-7 are less effective for removing fluid from wells.

Since the lifetime of the foam in samples No. 4-7 is inferior to the value of this indicator for the prototype sample,

0 The values of the moles of propylene oxide and ethylene oxide contained in the above samples were not included in the claims. The formula of the proposed isobrepi includes the values of the numbers of moles

5 propylene oxide and ethylene oxide within (boundaries), which provide a longer foam lifetime than the prototype sample, i.e. the values m 10 ... 25 and p 80 ..150,

0 The quantitative ratio of ingredients (block copolymers and water) in the proposed reagent is determined by the ability to effectively remove fluid from wells (Table 3).

5 When considering the data presented in Table. 3, we can draw the following conclusions. The concentration of the block copolymer in the reagent is 0.1 wt.% Corresponds to the value of the removal efficiency.

0 liquid (EML) 0.35 kg per 1 m3 of gas. This value of the ESM is an order of magnitude lower than the value of the ESM for the prototype reagent, equal to 2.45 kg / m. An increase in the concentration of the block copolymer from 0.1 wt.% To 0.2 wt.% At 5 leads to an increase in the efficiency of liquid removal by 1.40 kg / m, i.e. to a value of 1.75 kg / m, which approximates the value of the EOL for the prototype reagent. Thus, the concentration of the block copolymer is 0.2 May. % can be added below the lower limit of the content of this ingredient in the declared reagent.

A consistent increase in the concentration of the block copolymer from 0.2 wt.% To 0.5 wt.% Causes a corresponding increase in the value of the EOL to 3.95 kg / m3, i.e. by 2.20 kg / m. A further increase in the concentration of the block copolymer to 1.0 May. % gives an increase in the EOL value up to 4.10 kg / m3, i.e. only 0.15 kg of liquid per 1 m of gas.

Thus, it can be concluded that the concentration of the block copolymer of 0.5 wt.% Can be taken as the upper limit of the content of this ingredient in the declared reagent. The use of a reagent for removing liquid with a concentration of a block copolymer of more than 0.5 wt.% Is economically disadvantageous, since, for example, more efficient removal of liquid will give

twice the use of the reagent with a concentration of a block copolymer of 0.5 wt.%, than a single use of the reagent with twice the concentration of the block copolymer of 1.0 wt.%.

The block copolymers of propylene and ethylene oxides based on alkylphenols have technical advantages over the prototype (Table 4).

As follows from the data table. 4, sample number 2, i.e. the optimal variant of the claimed block copolymers exceeds the efficiency of the liquid removal by 1.6 times (3.95: 2.45).

To calculate the planned economic effect from application of block copolymers, data on the Poltava gas field control are taken, in wells of which the mineralization of formation water reaches 200 g / l or more, the gas condensate content is up to 40% by volume, the temperature in the wells up to 80 ° C and above. Under such conditions, only block copolymers of propylene oxide and ethylene can be effective for removing fluid from wells. According to the actual data from the Poltava GPU, the average additional gas production from the application to remove the reagent liquid of the prototype is 2,700 thousand meters in one well, “not for one. In this case, 0.35 tons of copolymers are consumed, and the cost of carrying out the injection of the reagent is 3.55 thousand rubles. Since the optimal variant of the proposed block copolymers exceeds the prototype in liquid removal efficiency by 1.8 times, when using back-to-amp block copolymers, the consumption of surfactants will correspondingly decrease in this case 0.35 t: 1.6 0, 22 tons per well per year.

The economic efficiency of the use of reagent for removing fluid from wells is expressed in the saving of a conditionally constant part of operating costs for gas production, due to the production of additional gas production as a result of an increase in well productivity. The magnitude of the economic effect is calculated by the formula:

Eup - Svn. where e is the economic effect:

Eup - saving the conditionally constant part of operating costs for gas production;

ZnA - the cost of implementing the development.

The calculation of the value of the eup is made by the expression

0

five

0

five

0

five

0

0 Soup DOEU - Q

where Soup is the annual amount of the conditionally constant part of operating costs for gas production;

TO - additional gas production, obtained as a result of the implementation of this development;

Q - the total volume of commercial gas production for the year.

The cost of implementing a QnD development is made up of the cost of the Zblock block copolymers and the cost of carrying out the injection charge ZaZk:

Link Zblock + Zak.

Since the surfactant consumption per well per year will be 0.22 tons, and the estimated price for block copolymers in the order of 1.5 thousand rubles per ton is:

Zblok 0,22 t 1,5 thousand rub. / T 0,33 thousand rub.

Since the cost of injecting the Zak reagent in one well per year is 3.55 thousand rubles, you can determine the following:

RUR 0.33 thousand rubles. + 3.55 thousand rubles .. 3.88 thousand rubles.

The amount of savings of the conditionally constant part of operating costs for gas production Eup can be calculated using actual data for the Poltava GPU (1987):

Soup 23970 thousand rubles: Q 8566475 thousand m3.

Since the additional production of gas BEF, obtained as a result of using the reagent for removing fluid, is 2,700 thousand meters per well per year, the value of Eup will be: 0 23,970 thousand rubles. 2,700

Jyn

8566475 - 2700

 7.56 thousand rubles.

Then, the economic effect from the use of block copolymers of propylene oxide and ethylene based on alkylphenols to remove fluid from wells will be per 1 well per year:

E Eup - Sound 7.56 thousand rubles. - 3.88 thousand rubles. 3.68 thousand rubles.

The economic effect per 1 ton of the injected block copolymers will be:

  3,68 thousand rubles,.,., ,, 1 t 022- 167 thousand RUB / t.

Claims (1)

Claims of Invention A reagent for removing liquid from gas and gas condensate wells, containing a surfactant and water, characterized in that, in order to increase the efficiency of removal from wells with highly mineralized water with a significant content of gas condensate and elevated temperature at the bottom, it contains as a surfactant block copolymers of propylene and ethylene oxides based on alkyl phenols of the general formula (С3НбО) t (С2Нч.О) pH, 0 where R is a C / 0 alkylphenol residue, in which R is a radical CeHi7-CioH2i: m is the number of moles of propylene oxide, equal to 10-25; p is the number of moles of ethylene oxide, equal to 80-150. with the following proportion of ingredients, wt.%: Block copolymer the specified General formula 0.2-0.5; WaterEverything, Table 1 Table 2 Table3 Note. Measurements were performed on sample No. 2 of the claimed block copolymers. Table 1). Note. measures (table 1). 1 measurements were carried out on samples No. 1-3 of the claimed block copoly. Continuation of table 3 Table4