RU2132455C1 - Method and pumping unit for injecting water into injection well - Google Patents

Abstract

FIELD: oil production industry. SUBSTANCE: method relates to injecting water into injection well with poorly permeable reservoirs for arrangement of selective local drowning. In realization of method, water is delivered in pipeline through well-head locking devices to pump inlet. Injection of water into bed is carried out by ensuring required injection pressure. Water is forced through non-return valve via pump-compressor pipes. Production string is protected from pressure differentials by means of packer installed above roof of oil bed. Pumping unit intended for realization of method comprises following components: pump-compressor pipes, well-head locking devices, pipe connection, immersed electric motor located in upper part of pumping unit, and sectional-type pump. Number of sections in pump depends on required injection pressure. Installed in lower part of pumping unit is compensator of vertical loads which is intended for taking out linear movements of pump-compressor pipes. Application of aforesaid method and device allows for more efficient recovery of fluids due to levelling of displacement front and involving poorly permeable reservoirs into development. EFFECT: higher efficiency. 2 cl, 1 dwg

Description

 The invention relates to the oil industry, and in particular to methods of pumping water into an injection well with low permeability reservoirs, and is intended to organize selective focal water flooding.

With the development of highly productive reservoirs of an oil field, the requirements for a reservoir pressure maintenance system (RPM) are changing. The introduction of focal flooding in the development of upper unproductive formations posed the problem of the transition to less productive equipment for the RPM. At existing cluster pumping stations (SPS), the connected injection wells have different injections (from 20 to 600 m ³ / day) and different required working pressure (13.0 - 20.0 MPa). The grouping of wells by injectivity is limited by the capabilities of pumping equipment at the pumping station. Injection wells with low permeability reservoirs, as a rule, are not involved in the development process.

 Known methods of maintaining reservoir pressure using pumps, providing pumping water from the lower reservoir to the upper or upper to lower reservoir, as well as methods for jointly-separate pumping of water [1, 2, 3], which requires a complex of oilfield facilities - the presence of a pit, pipelines , equipment, and water is pumped through the production string, which is unacceptable according to the technical conditions of the wells. In the presence of various injectivity characteristics, it is impossible to carry out a regulation mode for the process of developing an oil area using these methods.

 The objective of the invention is to increase the efficiency of development by leveling the front of the displacement and the involvement in the development of low permeability reservoirs.

 This problem is achieved by applying a method of injecting water into an injection well, including supplying water through a pipe through wellhead shutoff valves to a pump intake, while water is injected into the formation, providing the pressure necessary for injection, through a non-return valve through tubing, and to protect production casing against pressure drops use a packer installed above the roof of the reservoir.

 The pump installation for the implementation of the method consists of tubing, wellhead valves, nozzle, submersible motor and pump, while the submersible motor is located in the upper part of the pump installation, the pump is made sectional, the number of sections of which is interconnected with the discharge pressure, and in the lower part The unit is equipped with a vertical load compensator to remove linear tubing movements and weights from the pump unit.

 The method of pumping water into the injection well is implemented using the pumping unit shown in the drawing.

 A pump unit containing a compensator 4, a submersible motor 5 with a cable 6, which through a tread 7 is connected to the sectional pump 8 by a check valve 9 and an eccentric coupling 10, which serves to relieve the pressure of the sectional pump 8 along the impulse tube 11 with a pressure gauge mounted on the surface of the wellhead shutoff valve 2. The vertical load balancer 12 located below the eccentric sleeve 10 removes linear pump-compressor movements Tube (CNT) 13 and the pump unit weight. Tubing 13 is equipped with a packer 14 located above the roof of the reservoir. The annulus is filled with inhibited water.

 The pump installation regulates and maintains the operating mode of the injection well as follows.

 Water from the low pressure distribution piping system flows through a pipe (not shown in the drawing) through the wellhead shutoff valve 2 to the intake of the sectional pump 8. Having acquired the pressure necessary for injection, the water enters the formation through a check valve 9, which prevents spillage from the formation during shutdown, and tubing 13. To protect the production casing 1 from high pressure, use a package 14 installed above the roof of the reservoir. The pressure value is recorded through the eccentric coupling 10 and through the impulse tube 11. The number of sections of the pump unit is selected for the required working pressure and depending on the pressure at the pump intake 8, which allows the waterflood to cover various sections of the areas depending on the injectivity.

 The use of this invention for water injection can improve the regulation of the development of oil reservoirs, the mode of operation of the injection well does not depend on other wells connected to the pumping station, it allows you to partially automate the operation of the injection well, raise the working pressure at the mouth of the injection well, and select the pump size individually specific wells, in addition, provides the fundamental possibility of transition to a low-pressure system for maintaining reservoirs pressure with a multiple reduction in capital investment and operating costs. This invention can also be used for dispensing inhibitors, reagents in well treatment, waste water disposal.

Literature
1.SU 909134 A1, 02.28.82.

 2. SU 1361309 A1, 12.23.87.

 3. SU 1675543 A1, 09/07/91, Bogdanov A. A. Submersible centrifugal electric pumps for oil production. - M .: "Nedra", 1968, p. 88 - 89.1

Claims (2)

 1. A method of pumping water into an injection well, comprising supplying water through a pipe through wellhead shutoff valves to a pump intake, characterized in that the water is pumped into the formation, providing the pressure necessary for pumping, through the check valve through the tubing, and for protection production casing against pressure drops use a packer installed above the roof of the reservoir.  2. A pump installation for pumping water into an injection well, consisting of tubing, wellhead shutoff valves, nozzle, submersible motor and pump, characterized in that the submersible motor is located in the upper part of the pump installation, the pump is made sectional, and the number of sections is interconnected with a discharge pressure, and in the lower part of the installation there is a vertical load compensator for removing linear displacements of tubing.