RU143289U1 - DUAL-PUMP PUMPING SYSTEM FOR WATER DRAINING - Google Patents

Abstract

A double-acting pump system, comprising: a sucker-rod pump mounted on a tubing string — a tubing, the pump plunger having a controllable discharge valve and connected to a rod string; a shank mounted from a pump inlet valve to a packer separating the absorbing layer and a reservoir located under the absorber; - sub with holes installed in the tubing string between the pump and the wellhead, connecting the pump outlet to the annulus above the packer; - mouth howl rod coupled to the rod string, and passes through a wellhead stuffing box mounted on the wellhead and wellhead stuffing box is located under the tee, characterized in that a tee below wellhead stuffing box arranged additional sealing wellhead rod for sensing the pressure generated in the production string.

Description

The utility model relates to the oil industry, namely, to a device for the operation of highly watered oil wells.

A device and method are known (RU 2394153 C1, published on July 10, 2010) for operating a highly watered oil well. The method includes separate, thanks to the packer installed between the productive and the receiving reservoirs, pumping oil from the reservoir into the flow line with preliminary separation of the production in the well into oil and water, and pumping the separated water into the receiving reservoir. Above the packer installed above the reservoir, a pump is installed on the pipe string, which can be used as a sucker rod pump or electric submersible pump (rod string and electric cable are not shown), communicated by the inlet through the shank with a sub-packer space. The pump outlet through radial holes in the pipe string is in communication with the annulus above the packer. Pipes of smaller diameter are placed under the radial openings in order to increase the cross-sectional area of the annulus and reduce the speed of water downward, which eliminates the entrainment of oil by water into the receiving formation, since the speed of oil floating in water exceeds the speed of water downward. The oil separated during the gravitational separation of products in the well is pumped up to the wellhead through the annulus and along the pipe string above the radial holes, while the amount of oil entering the flow line is controlled, for example, with a control valve, and the water through the annulus is below the radial holes pumped into the receiving reservoir due to the pressure of the liquid column in the well and the excess pressure created by the pump. The interval of the receiving wellbore is reported by a separate tube with wellhead measuring equipment, based on the readings of which the quality of the water pumped into the receiving stratum is controlled.

The disadvantage of the above solution is the possibility of failure of a standard wellhead seal, because pressure may be required above the operating pressure of a standard wellhead gland to inject the required amounts of water into the absorbing formation.

The problem solved by this utility model is to reduce the water cut of the produced oil, and therefore increase the profitability of operation by lifting oil to the surface with a minimum amount of water and pumping most of the water into the overlying layer.

The specified technical problem is solved through the use of a double-acting pump system. In a flooded well from which an absorbing formation located above the producing formation is accessible and perforated, a sucker rod pump is launched on a string of tubing (tubing). The exposed formations are separated by a packer. A shank is used from the pump inlet valve to the packer. In the tubing string above the pump at a certain distance from the wellhead and directly below the wellhead, sub with holes are installed. The pump plunger is made with a controlled discharge valve and is connected to the rod string. On the flow line, a device is installed that limits and regulates the flow of fluid into the flow line (fitting), as well as a valve, pressure gauge and sampler. In order to quickly determine the performance, a flow meter is installed on the flow line. To assess the quality of water (content of mechanical impurities and oil products) injected into the absorbing layer, an additional pipe string (similar to a two-lift ORE (simultaneous separate operation) or a used flexible pipe) was lowered into the well parallel to the tubing, connected to the sampler. The pressure in the annulus at the wellhead is controlled by a manometer.

Moreover, since the pressure at the wellhead above 40 atm, that is, above the working pressure of a standard wellhead stuffing box, may be required to inject the required amounts of water into the absorbing layer, an additional wellhead stem seal is placed under the tee. An additional seal is designed to absorb the pressure created in the production casing (EC), while minor leaks will flow into the tee and through the branch to the flow line after the control device, where the oil pressure will already be. Thus, the wellhead gland operates in its usual conditions.

The technical result consists in increasing the reliability of the double-acting pumping system, due to the exclusion of the effect of increased pressure at the wellhead on the wellhead seal.

FIG. 1 schematically depicts a double-acting pumping system with a USHN (well sucker-rod pumping unit) for pumping water into an upstream formation.

In the flooded well 1, from which the absorbing formation 2 located above the producing formation 3 is accessible and perforated, a sucker rod pump 5 is lowered on the tubing string 4. The opened formations are disconnected by the packer 6. A shank 8 is used from the receiving valve 7 of the pump 5 to the packer 6. the tubing string 4 above the pump 5 at a certain distance from the wellhead and directly below the wellhead, sub 9 are installed with holes 10 connecting the pump outlet to the annulus above the packer. The plunger 11 of the pump 5 is made with a controlled discharge valve 12 and is connected to the rod string 13. A device 15 is installed on the flow line 14, which limits and regulates the flow of fluid into the flow line (fitting), as well as valve 16, pressure gauge 17 and sampler 18. For the purpose a flowmeter 19 has been installed to quickly determine productivity on the flow line. To evaluate the quality of water (content of mechanical impurities and oil products) pumped into the absorbing layer 2, the conduit is run parallel to the tubing 4 to the interval of the absorbing layer 2 and an additional pipe string 20 (similar to a two-lift ORE or a used flexible pipe) connected to the sampler 21. The pressure in the annulus 22 at the wellhead is controlled by a pressure gauge 23.

The principle of operation of a double-acting pumping system with USSHN for pumping water into the upper absorbing layer is as follows.

Watered products from the underlying reservoir 3 through the liner 8 enters the pump 5 and then through the tubing string 4 it rises to the nozzles 9 and through the holes 10 enters the cavity of the well EC. Below the holes 10 in the well will be water, since the density of water is higher than the density of oil.

Products at a slow speed rises to the wellhead over the entire cross section of the well, while there is a gravitational separation of water and oil. The adjusting device 15 is experimentally tuned so that, by virtue of fitting, to supply significantly less liquid to the flow line than the pump is pumping out of the reservoir. At the same time, overpressure is created in the well, under the influence of which the main amount of water is pumped into the absorptive layer 2, and all oil taken from the productive formation, which floats up to the wellhead through the EC, and a small amount of water enter the flow line.

The amount of water pumped into the absorbing layer is defined as the difference between the pump capacity and the amount of liquid lifted to the surface, and can be varied widely by a regulating device 15. The productivity of fluid selection from the reservoir is regulated by changing the USHN operating mode (stroke length - swing frequency). Water quality is monitored at the required frequency by analyzing samples taken through the sampler 21 from the cavity of the additional pipe string 20, where water flows from the lower part of the well under the influence of excess pressure controlled by a pressure gauge 23.

Watered products from the underlying reservoir enter the pump and then through the tubing string it rises to the nozzles and through the holes enters the cavity of the EC well. Water will be located below the holes in the well, since the density of water is higher than the density of oil.

Products at a slow speed rises to the wellhead over the entire cross section of the well, while there is a gravitational separation of water and oil. The adjusting device is experimentally tuned so that, by plating, to supply significantly less liquid to the flow line than pumping the pump out of the reservoir. At the same time, overpressure is created in the well, under the influence of which the main amount of water is pumped into the absorbing layer, and all oil taken from the productive layer, floating up to the wellhead through the EC, and a small amount of water enter the flow line.

The amount of water pumped into the absorbing layer is defined as the difference between the pump capacity and the amount of liquid raised to the surface, and can be varied widely by a regulating device. The productivity of fluid withdrawal from the reservoir is governed by a change in the USHN operating mode (stroke length - swing frequency). Water quality is monitored at the required frequency by analyzing samples taken through the sampler from the cavity of an additional pipe string, where water flows from the bottom of the well under the influence of excess pressure controlled by a pressure gauge.

Since the pressure at the wellhead above 40 atm, that is, above the working pressure of a standard wellhead stuffing box 24, may be required to pump the required amounts of water into the absorbing layer, an additional seal 26 of the wellhead shaft 27 is placed under the tee 25. The additional seal 26 is designed to absorb the pressure created in the EC at the same time, minor leaks taking place will flow into the tee 25 and through branch 28 to the flow line 14 after the regulating device 15, where the pressure of the pipeline will already be. Thus, the wellhead seal 24 operates in its usual conditions.

Claims (1)

Double acting pump system containing: - a sucker rod pump mounted on a string of tubing - tubing, and the plunger of the pump is made with a controlled discharge valve and connected to the string of rods; - a shank installed from the suction valve of the pump to the packer separating the absorbing layer and the productive layer located under the absorbing one; - sub with holes installed in the tubing string between the pump and the wellhead, connecting the pump outlet to the annulus above the packer; - the wellhead rod connected to the rod string and passing through the wellhead seal installed at the wellhead, wherein a tee is located under the wellhead seal, characterized in that under the tee below the wellhead seal there is an additional wellhead shaft seal to absorb the pressure created in the production string.