RU2132450C1 - Method for removing asphalt-resin and paraffin depositions - Google Patents

Abstract

FIELD: oil and gas production industry. SUBSTANCE: according to method, removed asphalt-resin and paraffin depositions are dispersed in oil field equipment. Method implies delivery of inhibitor into annular space in amount of 0.5-20 mas.% of volume of oil contained in product being pumped out and located in internal space of pump-compressor pipes and in annular space within limits from dynamic level to pump inlet. Operation of immersed pump is performed in closed circuit system consisting of pumping pipes and discharge line. Pumped-out product together with reagent circulates through closed circuit system. Application of aforesaid method improves efficiency of inhibiting asphalt-resin and paraffin depositions together with increasing amount of product recovered. EFFECT: higher efficiency. 1 tbl

Description

 The invention relates to the oil industry and can be used to remove tar and paraffin deposits and dispersing them in oilfield equipment.

 There is a method of dewaxing wells, which consists in pumping hot oil or hydrocarbon gas into a well (ed. St. USSR N 1270298, class E 21 B 37/06, 1986).

 A known method of dewaxing wells, including the circulation of the technological solution in a closed cycle, the cyclic pumping of the technological solution into the well, cleaning of the compressor pipes and the technological solution (patent RU N 2003783, cl E 21 B 37/00, 1993).

 A disadvantage of the known methods is the incomplete amount of work on dewaxing due to the complexity and low efficiency of the removal of paraffin.

 The aim of the invention is to increase the efficiency of inhibition of paraffin and an increase in the volume of extracted products.

 This goal is achieved by the fact that in the known method of removing salts of paraffin deposits, including the cyclic supply of the inhibitor reagent to the annulus, the circulation of the mixture of pumped products with the reagent in a closed cycle, the reactant inhibitor is supplied in a volume of 0.5 - 2.0 wt.% from the volume of oil in the pumped-out products, enclosed in the inner cavity of the tubing and in the annulus from the dynamic level to the pump intake, and the operation of the deep pump is carried out in a closed ring - pump pipes s and the delivery line, in which the mixture circulates and pumped product with the reagent.

 The proposed method is as follows. The estimated volume of the paraffin scale inhibitor is poured into the annulus of the well. The valve of the annulus closes, the bypass valve opens along the wellhead fittings, i.e. the well is put into operation "on itself" mode. The paraffin inhibitor also contains a solvent. Passing repeatedly through the waxed interval, the inhibitor gradually loosens and disperses paraffin crystals, forming a loose mass. The loose mass passes into the pumped product and is taken out of the well. The operating time of the well "on itself" depends on the performance of the downhole pump. For wells operated by pumps with a diameter of 32 mm, the optimum “on-the-go” operating time is 72-96 hours. For wells with pumps with a diameter of 43 mm - 48-50 hours. The time of continuous "self" operation of wells operated by the ESP is dependent on the cooling rate of the submersible electric motor (PED) by the fluid coming from the formation and is within 6-8 hours. After this time, the ESP is turned off for cooling for 3-4 hours. Then the cycle is repeated. The operating time of the well "in itself" in the second cycle is reduced by 1-2 hours, since the flow of fluid from the formation into the well is sharply reduced. PED cooling time after the second cycle is also 3-4 hours. Usually, for complete cleaning of tubing from paraffin in the wells operated by the ESP, it is sufficient to conduct at least 3 cycles.

 Inpar-1, PPS, SNPCH-7523 can be used as an inhibitor. Laboratory and field studies have found that the optimal percentage is the one percent concentration of the inhibitor Inpar Inpar-1 in oil.

 The table shows the test results of this method in wells operated by ESP and SSH. The table shows that the average volume of produced products in the group of wells increased 1.62 times. Due to the free flow of fluid in all wells, the dynamic level decreased. The average inter-treatment period increased by 2.85 times.

 The re-treatment time in the proposed method is determined by measuring the fluid flow rate and the dynamic level in the wells operated by the ESP and the removal of the dynamogram in the wells operated by the secondary school.

 Thus, the application of the proposed method in wells increases the efficiency of inhibition of paraffin deposits, increases the volume of produced products and the inter-treatment period. The economic effect excluding additional oil was 1.2 million rubles per well.

Claims (1)

 A method for removing asphalt-resinous and paraffin deposits, including the cyclic supply of an inhibitor reagent to the annulus, the circulation of the mixture of pumped products with the reagent in a closed cycle, characterized in that the reactant inhibitor is fed into the annulus in an amount of 0.5 - 2.0 wt.% from the volume of oil in the pumped-out products, enclosed in the inner cavity of the tubing and in the annulus from the dynamic level to the pump intake, and the operation of the deep pump is carried out in a closed ring - pump pipes and flow line, through which the mixture of pumped products with a reagent circulates.

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