RU2316642C1 - Asphalt-tar-paraffin deposit removal composition - Google Patents

Abstract

FIELD: oil production, particularly devices to remove asphalt-tar-paraffin deposits from well bottom zone, discharge lines of oil-gathering reservoirs, oil-field equipment, oil production and refinery plants.

SUBSTANCE: composition comprises 70% by weight of DP-65 depression additive used as 40% jet-fuel solution and 30% by weight of HPP-004 inhibitor.

EFFECT: increased efficiency.

2 tbl, 1 ex

Description

The invention relates to the field of oil production, in particular to compositions for removing asphalt-resin-paraffin deposits (paraffin deposits), and can be used to remove paraffin deposits from the bottomhole formation zone, flow lines of oil collecting manifolds of oilfield equipment for oil producing and oil refining enterprises.

The process of deposition of asphalt-resin-paraffin substances worsens the technical and economic indicators of oil production: the overhaul period of wells is reduced, oil losses and energy consumption are increased, accident rate at facilities is increased, conditions are created for the spread of contamination of the oilfield territory, etc.

The known composition [RU No. 2183650 C1, SKK 3/00, EVB 37/0] for removing asphaltene-resin-paraffin deposits, containing, vol.%:

aliphatic hydrocarbons 50.0-8.0 polar non-electrolyte 2.0-5.0 nonionic surfactant 1.0-2.0 solvent-absorbent-A-2 heavy 2.0 aromatic hydrocarbons rest

The composition, although it exhibits a synergistic effect, but its consumption is significant for achieving relatively high efficiency. In addition, this composition requires laborious costs in its manufacture. The composition also contains a large number of solvents, which are highly volatile, which complicates the technology of its application.

Currently, to prevent the formation and removal of paraffin, various inhibitors are used, depressant additives, as a rule, of single-functional action.

So known is the KhPP-004 inhibitor, designed to prevent the formation of paraffin deposits and remove hydrate deposits in oilfield equipment and pipelines during oil production and transportation, manufactured according to TU 39-43122541-OP-14-98. It is a mixture of an organophosphorus compound, monoethanolamine and hydroxyalkylated alcohols and urethane derivatives in a mixture of solvents: methanol, oil solvent (Nefras A-130/150 or A-120/200).

Appearance of the inhibitor HPP-004: a homogeneous transparent liquid from light yellow to yellow.

The disadvantage of the KhPP-004 inhibitor is its low efficiency, which does not exceed 47% in the concentration range up to 1000 g / t (studies were conducted on oil from the Kharampur field).

The depressant additive DP-65 according to TU 6-02-594 is a solid low-toxic substance from brown to dark brown.

DP-65 and its analogues are polyamides - condensation products of FFA fraction C ₂₁ -C ₂₅ and polyethylene polyamines in various ratios. DP-65, designed to reduce the pour point of oils and petroleum products containing high-melting solid hydrocarbons, is ineffective in diesel fuels. It also has an inhibitory effect on paraffin. The inhibition efficiency is 33% in the concentration range up to 1000 g / t (studies were carried out on oil from the Kharampur field).

The technical challenge facing the inventor is to develop a composition of inhibitors of paraffin in order to increase the effectiveness of inhibitory protection against paraffin.

To solve this problem, the composition of the inhibitor of paraffin deposits KhPP-004 and the depressant additive DP-65 (40% solution in jet fuel) was studied, designed to remove asphalt-resin-paraffin deposits in wells and oilfield equipment.

Each of the components of the resulting composition has its own specific effect on a certain type of paraffin.

The composition of the ingredients forms a homogeneous composition, the effectiveness of which to remove paraffin deposits on oilfield equipment is increased due to the synergism of the developed composition.

The optimal ratio of components, wt.%:

Inhibitor HPP-004 30,0 Depressor additive DP-65 (40% solution in jet fuel) 70.0

The study of the effectiveness of the compositions was carried out in laboratory conditions at the Cold Rod installation on the oil of the Kharampur field according to the known method described in RD 39-0148070-003VNII-86.

The results of the study are shown in table 1.

Solutions were prepared immediately prior to testing.

The results of laboratory tests showed that the most active component is the depressant additive DP-65. The results of determining the optimal highly effective composition of the mixture showed that the mixture is most active, where the content of DP-65 components (40% solution in jet fuel): KPP-004 70.0: 30.0 (wt.%).

The synergism was quantified by comparison with the additivity curve. According to the additivity rule, the mass of a mixture of components is equal to the sum of the masses of the components that make up this mixture, multiplied by the corresponding mass fractions of the mixture.

where m ₁ is the mass of paraffin deposits deposited on the rod in the experiment with the addition of a 40% solution of DP-65 in jet fuel, g;

m ₂ is the mass of paraffin deposits deposited on the rod in the experiment with the addition of an inhibitor of HPP-004, g;

n ₁ is the mass fraction of the first inhibitor in the mixture;

n ₂ is the mass fraction of the second inhibitor in the mixture.

The effectiveness of the additivity of the mixture (E _a ) we find by calculation:

where m _o - the mass of paraffin in the control experiment, g;

m _a - additive mass of paraffin, calculated by the formula (1),

We denote the efficiency obtained in this way as the additivity efficiency. For a quantitative assessment, we use the ratio S = Esm / Ea. If Esm / Ea> 1, then a synergistic effect is manifested, and if Esm / Ea <1, then the effect is antagonistic.

Based on the results, table 2 is constructed.

The dependence of Esm / EA on the content of DP-65 is a curve with extreme points. It allows you to determine the acceptable content of the depressant additive DP-65 in the mixture, in which the effectiveness of the inhibition of the mixture (Esm) will exceed the additive effectiveness (EA) at various specific costs.

One of the most important criteria when choosing an inhibitor and its dosage is to provide the necessary level of inhibition efficiency. Table 2 allows you to choose the composition of the mixture and the specific consumption at which the composition has the greatest efficiency, as well as numerically evaluate the synergistic effect.

The results presented in table 2 can be divided into two areas, each of which corresponds to a certain content of DP-65 in the mixture.

For costs of 100 g / t and 250 g / t, the region of 0-50% is, as it were, a mirror image of the region of 50-100%.

The region of 0-50 wt.% DP-65 in the mixture is the region where the phenomenon of synergism is observed for concentrations of 50, 100 g / t; for a concentration of 250 g / t, 0-30 wt.% DP-65 is a synergistic region, and 30-50 wt.% is a transitional region.

The range of 50-100 wt.% DP-65 in the mixture. For all concentrations - the area of synergy. The maximum value of synergism is observed when the ratio of the inhibitor HPP-004 and the additive DP-65 (40% solution in jet fuel) is 30.0: 70.0. The effectiveness of the mixture at this point at a concentration of 50 g / t exceeds the additive efficiency by 2.6 times.

The effect of synergism depends on the total concentration of the composition. With increasing concentration, it decreases, while the effect of antagonism increases (mixtures with a concentration of 500 g / t and higher do not have a synergistic effect over the entire range of DP-65 content in the mixture).

After the studies, it was found that the optimal ratio of the components in the mixture is 70.0 DP-65 (40% solution in jet fuel): 30.0 KhPP-004, and the working range of concentrations is up to 250 g / t.

To select the most effective inhibitor by the effect of inhibition (without taking into account the cost of inhibitors), two parameters must be taken into account: the value of efficiency and concentration.

An inhibitor is preferred that, for example, with equal efficacy shows this effect at a lower concentration.

The proposed composition of the mixture of inhibitors of asphalt-resin-paraffin deposition in comparison with the known compositions has new properties that are not a simple summation of their known properties. Namely, in comparison with the prototype and individual components of the inhibitors, the proposed composition has greater efficiency, lower consumption and, accordingly, has a lower unit cost.

These advantages allow you to:

use a more efficient method for periodic injection of the claimed composition into the annulus of producing wells (the possibility of easy preparation both in stationary conditions and in the field);

economically and rationally use a solution of the composition with determining its optimal content in the produced oil;

the components that make up the composition do not affect the quality of the oil preparation.

Example: The composition is prepared as follows:

A 40% solution of the depressant additive DP-65 in jet fuel and an inhibitor of HPP-004 in a ratio of 70.0: 30.0 (wt.%) Are dosed in a bottle with a ground stopper. The bucks are closed with a ground stopper, placing a piece of filter paper under it and mix thoroughly.

Table 1
The results of the inhibition of the initial inhibitors of paraffin deposits and their compositions studied in the oil of the Kharampur field Component composition, wt.% The total concentration of the mixture, g / t fifty one hundred 250 HPP-004 21.3 38.7 49.7 DP-65 (40% solution in kerosene) 19.5 51.7 56.0 HPP-004: DP-65 (40% solution in kerosene) 30.0: 70.0 42.7 53.6 44.6 HPP-004: DP-65 (40% solution in kerosene) 50.0: 50.0 52.3 52.1 60.9 HPP-004: DP-65 (40% solution in kerosene) 70.0: 30.0 53.0 64.3 55,2 table 2
The Esm / Ea ratio for the composition of the KhPP-004 inhibitor and the depressant additive DP-65 in the oil of the Kharampur field at various concentrations The concentration of the mixture, g / t The content of DP-65, wt.% 0 thirty fifty 70 one hundred fifty 1,0 2.1 2.6 2.7 1,0 one hundred 1,0 1.3 1,2 1.3 1,0 250 1,0 0.9 1,2 1,0 1,0

Claims (1)

Composition for removing asphalt-resin-paraffin deposits in oilfield equipment, including the depressant additive DP-65, used in the form of a 40% solution in jet fuel and an HPP-004 inhibitor in the following ratio, wt.%: Depressor additive DP-65 (40% solution in jet fuel) 70.0 Inhibitor HPP-004 30,0