RU2388905C1 - Method of preparation and supply of liquid-gas mixture to bed - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: method involves in-series installed reservoir for water preliminary discharge - RWPD, hydrophobic liquid sump tank - HLST, ejector assembly with power pump, pump booster station - PBS with instruments, supply pipelines of gas and operating liquid. In order to increase the creation effectiveness of optimum volumes of mixed components - water+gas, the main supply line of waste water from RWPD and HLST is divided into two flows on PBS, with simultaneous utilisation of heat and residual chemicals of oil preparation: into an independent pump with ejector and pipeline of additional supply of working liquid for preliminary gas compression. It leads to heating of gas-liquid mixture due to energy loss in ejector, which prevents hydrating, into pipeline with measuring device for introduction of solution of corrosion inhibitor of low concentration and dehydrating solution.

EFFECT: increasing efficiency of quality of preparation and supply of gas-liquid mixture to bed.

2 cl, 1 tbl, 1 dwg

Description

The invention relates to oil production, in particular to technologies for enhancing oil recovery by preparing and injecting a gas-liquid mixture into a formation, and can be used in the oil and gas industry.

Known installations for the preparation and injection of a gas-liquid mixture using a booster pump and compressor unit (for example, RF Patent No. 2151911, class F04B 23/06, 1977), and technology for the preparation and injection of a water-gas mixture into a formation (RF patent No. 2190760, ЕВВ 43/20, 2002, BI No. 28).

The closest and accepted as a prototype is the technology and technique of water-gas treatment of the formation to increase hydrocarbon recovery and utilization of associated gas using pump-ejector systems (A.N. Drozdov, I.A. Krasilnikov, V.P. Telkov, A.A. Fatkullin, T.V. Chabina. NTZ Territory Neftegaz, 2008, No. 8, pp. 54-61), including an ejector of the first stage of gas compression, multi-stage vane pumps, a separator and ejector of the second degree of gas compression and subsequent injection of the gas-gas mixture into layer.

However, this method has several disadvantages, since it does not provide for the technology of purification of the supplied water to the ejector, which leads to a decrease in the gas compression process and the wear of the ejectors due to the presence of EHF (mechanical impurities) and residual oil products. Therefore, this scheme can not be effectively used in integrated schemes for the preparation of oil, and the utilization of produced water for flooding. In addition, there are no comprehensive schemes for supplying corrosion inhibitors and solutions for the dehydration formation, for example, methanol together with a corrosion inhibitor.

The objective of the invention is to increase the efficiency of the quality of preparation and injection of a gas-liquid mixture into the reservoir. This problem is solved by dividing the injected wastewater into two streams after supplying a preliminary water discharge (RVS) from the reservoir to a hydrophobic liquid sump with a filter (OGZhF), the first stream to the NBU and the second stream to compress the gas supplied to the NBU. Gas compression occurs due to an energy pulse in the ejector from the circulating liquid, where energy losses are used to heat the mixture, which prevents hydrate formation.

The drawing shows a diagram of the preparation and injection of a gas-liquid mixture into a reservoir, which includes a preliminary water discharge tank 1, a hydrophobic liquid sump with a filter (OGZHF) 3, pipelines 2, 4, 6, 11, 13, 15, 16, 18, a booster pump 5 , metering pump 7, gas supply line 9, gas separator 10, booster unit (NBU) 12, pump unit for supplying water to NBU 14, comb unit 17, injection well 19, downhole disperser 20, reservoir 21.

The method is as follows. Wastewater from the preliminary water discharge unit from the tank 1 is supplied for additional purification from mechanical impurities and oil products through pipeline 2 to the sump 3. Then, the wastewater is divided into 2 streams. The first autonomous flow through pipeline 4 arrives at the intake of pump 5, the output of which creates a pressure of 1-3 MPa, depending on the volume of gas supplied through pipeline 9 to the ejector 8. The gas and water flow rates are regulated by instrumentation in the autonomous control mode . Then, the gas-water mixture enters the high-pressure gas separator 10 with a level regulator in which the gas phase is separated and the compressed gas is piped through 11 to the NBU. From the gas separator, the working fluid through the pipe 13 enters the intake of the pump 5, forming an autonomous gas compression line. A low concentration corrosion inhibitor mixture, for example, with methanol, is supplied to the main line of the working fluid by a metering pump to prevent hydrate formation in waste water pipelines with chemical residues increases the stability of the gas-liquid mixture against separation and phase decomposition. In the NBU 12 phases (gas + water) are mixed and injected onto a high-pressure comb 17, and pumped through a pipe 18 into an injection well 19. A disperser, for example, of a cylindrical shape with a piston, is installed on the bottom of the tubing. The piston is held by a stripped spring, which closes the hole in the cylinder according to the design pressure and flow rate of the incoming mixture for injection into the reservoir 21.

The volume of the mixed components is regulated by preliminary tests and obtaining the experimental dependence of the volumetric content of the mixed phases (figure 2).

where Vzh is the volume of liquid in the gas-liquid mixture;

Vg is the volume of gas (taking into account the pressure in the gas separator 10).

The results of the implementation of this technology are shown in the table. Thus, the injection volume of the gas-liquid mixture due to optimization of the ratio of the volume of the mixed phases by preliminary compression of the volume of gas entering the NBU increased by 7 times.

The results of preliminary compression of the volume of gas entering the NBU m - Dependence of the volume content of the mixed phases Vzh - the volume of liquid, m ³ Vg - gas volume, m ³ Rg - gas pressure, atm 2.2 280 350 3 3,7 280 780 3,5 4.9 280 1100 four 6 280 1400 4,5 7.2 280 1740 5 8.8 280 2200 5.5 9.7 280 2450 6

Claims (2)

1. A method of preparing and injecting a gas-liquid mixture into a reservoir, including a sequentially installed reservoir for preliminary discharging of RVS water, a hydrophobic liquid sedimentation tank ОГЖФ, an ejector unit with a power pump, a pump and booster unit of the NBU with control and measuring devices, pipelines for supplying gas and working fluid, characterized in that, in order to increase the efficiency of the process of creating optimal volumes of mixed water + gas components, the main supply line of wastewater with RVS and OGHF is divided into two flow to the NBU, with the simultaneous utilization of heat and residual chemicals from oil preparation: to a stand-alone pump with an ejector and an additional supply of working fluid for preliminary gas compression, which leads to heating of the gas-liquid mixture from energy loss in the ejector, preventing hydrate formation; to a pipeline with a dispenser for introducing a solution of a corrosion inhibitor of low concentration and a dehydration solution. 2. The method according to claim 1, characterized in that, for the purpose of additional monodispersion of the water-gas mixture, a dispersant with an adjustable degree of dispersion in flow rate and pressure is installed at the bottom of the injection well in the bottom of the tubing.

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