RU2435943C1 - System of highly wet hole stream gathering and utilisation of produced water - Google Patents

Abstract

FIELD: gas and oil production. ^ SUBSTANCE: system consists of producers, of highly wet producers, of inactive wet holes, of group calibrating device - GCD, and of pump-compressor, output of which is connected with pressure wells through distributing manifold. According to the invention, the highly wet producers are connected directly with at least one pump-compressor by means of discharge lines of the GCD for pumping production of highly wet wells into inactive wet holes via discharge lines of the GCD and further along lift pipes through a nozzle. The nozzle consists of a head with connecting thread and two branches inside of which there are located a vertical channel and a grate of directing plates. They facilitate formation of a flat tangential near-the wall flow of pumped fluid descending at angle 45 to cross section of the borehole. Also, the descending flow has zero rate in its central part whereto there are driven globules of oil and gas forming an ascending flow with their continuous accumulation in an upper section of the borehole. Oil and gas are withdrawn from annular space into an oil collector by flow lift procedure with pumping water into the reservoir. ^ EFFECT: increased oil yield of reservoir at simultaneous reduction of material expenditures for production of water maintaining reservoir pressure, for collection and preparation of oil wells production. ^ 3 dwg

Description

The invention relates to the oil industry, in particular, can be used in the development of oil deposits with maintaining reservoir pressure, as well as in field collection systems for produced products.

Known technological installation of preliminary water discharge (UPSV) [1], performing the functions of preliminary separation of produced water for injection into an oil reservoir. UPSV simultaneously serve several cluster sites (on average no more than 40-50 wells) and are in close proximity to them. The most widespread are UPSW with the use of pipe water separators. UPSW include tubular water separators, in which well products are divided into oil, gas and water. Water with the help of pump-compressors is supplied to the RPM system. Petroleum gas and oil are delivered to buffer tanks, from which gas is supplied to the gas collection system without compressor, and oil is pumped to the collector by means of compressor pumps.

The work [2] presents the results of cost estimates for the implementation of the UPSW using tubular construction units. Based on the results of studies of the quality of discharged water and the evaluation of technological indicators carried out in [2], it was found that the optimal field of operation of the WWTP is in the range of water discharge to a residual water cut of 60-80%. The oil content in the discharged water does not exceed 50 mg / l, which corresponds to the water quality requirements for the PPD system.

The disadvantages of the known UPVS [1] include:

- water discharge from 83 to 98% requires the implementation of a technological scheme with costs at least 1.8 times higher compared to schemes that provide water discharge up to 83%, and for water discharge more than 98% the cost of arrangement will be at least 2 times higher [ 2];

- The special climatic conditions of Western Siberia require additional heating of the nodes of the collection and preparation system.

Closest to the technical nature of the claimed device is a system for the disposal of associated oil gas and produced water [3]. The system [3] comprises at least one production well connected to a separator. The output of the separator for oil with residual water and gas is connected to the first pump-compressor. The outlet or exits of the water and gas separator are connected to a second compressor pump, the outlet of which is connected to a dispersant connected to an injection well or a water distribution comb of injection wells. The separator is a horizontal separator having large and small compartments, while an overflow pipe for oil extraction is installed in a large compartment.

The disadvantages of the known system [3] include the presence of a separator, in which the products of highly watered wells are divided into low-watered oil, which is supplied to the collection system using a compressor, and a water-gas mixture, which is pumped into another injection well or wells using another compressor.

The aim of the invention is to reduce material costs for water production for the reservoir pressure maintenance system, for the collection and preparation of oil well products while increasing oil recovery.

Achieving this goal is based on the features of the oil and gas gathering system in Western Siberia, namely, cluster wellhead placement. For irrigated oil fields, the discharge of water directly on the bushes is an important technological technique, which reduces the cost of pumping liquid and preparing oil. At the same time, the problem of the most complete development of oil fields is solved. Production of wells having a high water cut of 80% or more, a high natural temperature of 30-40 ° C and a low content of mechanical impurities up to 20 mg / l can be directly injected into the reservoir through inactive waterlogged wells to maintain reservoir pressure. This allows for efficient separation with a high degree of phase without additional heating of the product and with the already existing volume (inactive waterlogged wells) of the settling equipment.

The essence of the invention lies in the fact that the production of highly watered wells, the water cut of which is 80% or more, through flow lines of the gas distribution unit, bypassing the multi-way switch of the wells, enters the input of the compressor pump, the output of which is connected to the distribution comb. The distribution comb is connected by flow lines of the gas distribution unit with inactive waterlogged wells. Well products having high water cut are pumped through the elevator pipes through nozzles consisting of a head with a connecting thread and two branches, inside of which there is a vertical channel and a lattice of guide plates. The nozzle allows you to form a flat tangential wall wall downward flow of injected fluid. In the central part of the wellbore, the velocity of the tangential downward flow is zero. As a result, conditions are created for the formation of two counter-directed flows: a tangential downward near-wall flow of heavily-watered well products and an upward axial flow of oil and emulsion globules released from watered well products. This leads to continuous accumulation of oil and natural gas in the upper part of the wellbore. The selection of oil and natural gas is carried out from the annulus of the injection wells in a fountain way to the oil reservoir, and water is pumped into the reservoir.

Thus, the claimed device meets the criteria of the invention of "novelty." When studying other technical solutions in this technical field, the features that distinguish the claimed invention from the prototype were not identified and therefore they provide the claimed technical solution with the criterion of "significant differences".

The essence of the inventive system for the collection of products of highly watered wells and utilization of produced water is illustrated by the following drawings.

Figure 1 presents a schematic diagram of a device for a cluster system for collecting products of highly watered wells and pumping it into injection wells.

Figure 2 shows the device nozzle for forming a tangential parietal downward flow of injected fluid.

Figure 3 shows the development of the tangential near-wall flow of injected fluid.

The device of the cluster system (Fig. 1) includes a bush of oil production wells 1, part of which is connected directly to the gas distribution unit, and the other part of production wells with high water cut is connected by flow lines of the gas distribution unit to the input of the compressor pump 2. The output of the compressor pump 2 is connected to the distribution comb 3, which is connected by flow lines of GZU with idle waterlogged wells 4. Oil and gas are taken from the annulus of the injection wells into the oil collector 5, and water is pumped into the reservoir Art.

The nozzles for the formation of a tangential near-wall downward flow of the injected fluid (Fig. 2) is a head 1 with a connecting thread, necessary for connecting it to the column of elevator pipes, and two branches 2. Inside the branches 2, a vertical channel 3 is located, providing uniform distribution of the flow along the branches , and the lattice of the guide plates 4. The profile of the guide plates 4 forms a flat tangential wall wall descending at an angle of 45 ° to the cross section of the wellbore. second fluid.

The development of the tangential near-wall downward flow of the injected fluid (Fig. 3) is associated with the interaction of the outflowing fluid with the fluid filling the cylindrical space of the wellbore 1. The interaction of the jet with the wall strongly influences the swirling jets developing inside the cylindrical channel 1. Therefore, a sharp change in the flow velocity occurs in the near-wall part of the jet. As a result, a tangential downward flow is formed with a maximum velocity near the wall of the cylindrical channel (velocity plot 2). In the central part of the cylindrical channel, the velocity of the tangential downward flow is zero. The oil globules and emulsions 3 contained in the production of highly flooded wells are displaced by a heavier dispersed medium (water) into the flow region at lower speeds, i.e. to the axial region of the wellbore. As a result, conditions are created for the formation of two counter-directed flows: a tangential descending near-wall flow of injected fluid and an upward flow of oil and emulsion globules displaced from the production of watered wells. This leads to the continuous accumulation of oil and natural gas in the upper part of the wellbore, which allows for their continuous selection in a fountain way.

The use of the inventive system for collecting products of highly watered wells and utilization of produced water provides the following advantages compared to existing systems:

1) the exclusion of material costs for water production for reservoir pressure maintenance systems due to the existing infrastructure of the cluster equipment system;

2) reduction of material costs for the arrangement of cluster sites with independent separation systems;

3) it becomes possible to maintain the reservoir pressure of a single remote well pad;

4) protection of the environment from pollution due to a closed cycle carried out directly at the well sites according to the scheme “production watered well - injection well - reservoir - production well”.

Information sources

1. Improvement of preliminary water discharge at the fields of OAO Yuganskneftegaz / V.A. Kryukov, N.V. Pestretsov et al. // Oil industry. - 2003. - No. 4. - S. 114-116.

2. Strategic development of systems for collecting and transporting highly water-borne well products of OAO JSOC Bashneft ./ D.Yu. Gizbrecht, S.F. Pivovarova et al. // Oil industry. - 2010. - No. 2. - S.-102-105.

3. Patent RU No. 2317408. Published 02/20/2008. A method for utilization of associated gas and produced water and a system for its implementation. / Klyushin I.Ya., Koshkin K.I., Chaika S.E., Khasanov E.M., Gorbunov SI., Konovalov V.V., Migunova SV., Sitenko V.T., Shkurov O.V.

Claims (1)

A system for collecting water-well wells and utilization of produced water containing production wells, production wells with high water cut and idle water-logged wells, a group metering unit — GZU, a pump-compressor, the outlet of which is connected to injection wells through a distribution comb, characterized in that the production wells with a high water cut are connected by flow lines of the gas distribution unit directly to at least one pump-compressor for pumping well products with high water cut into inactive waterlogged wells along flow lines of gas distribution lines and then through elevator pipes through nozzles, consisting of a head with a connecting thread and two branches, inside of which there is a vertical channel and a lattice of guide plates, which make it possible to form a flat tangential wall wall descending at an angle of 45 ° to the cross section of the wellbore of the injected fluid flow, in the central part of which a downward flow velocity of zero is ensured with displacement in e globules of oil and gas and the formation of their upward flow with continuous accumulation in the upper part of the wellbore, while the selection of oil and gas is provided from the annulus in a fountain way to the oil collection reservoir with injection of water into the reservoir.

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