SU953200A1 - Deep-well flowmeter for flooded oil wells - Google Patents

Description

The invention relates to downhole geophysical instruments, namely, downhole flow meters, designed to measure the flow of oil and water in heavily watered wells or in low-yield oil wells with stagnant water, in which drip oil flow is observed.

Devices for measuring the flow rate of oil in wells with stagnant water are known, comprising an absolute packer, a water-oil position position sensor (HHP), a branch pipe with windows and an actuator. The pipe is located sensor fluid flow. The space below the packer, bounded by the inlet of the branch pipe and the walls of the well, form an area in which droplets of oil accumulate. The position sensor is installed in the accumulation zone of oil at a fixed distance from the packer so that the flow of liquid in the pipe does not affect the measurement results. Oil consumption is determined by the time of filling a fixed volume with oil, i.e. oil consumption is measured by a volume method. A fluid velocity sensor is available in the device to determine the flow rate of all fluid.

The device allows to measure the oil consumption in watered low-rate wells 1 with a sufficient degree of accuracy.

However, the accuracy of measuring the flow rate of all liquid and water is low, since the flow rate of all liquid is measured by a speed sensor, i.e. turbine flowmeters. Therefore, the accuracy of determining the flow rate of water from measurements of oil and all liquid will be low.

The aim of the invention is to improve the accuracy of determining the flow

15 water.

The goal is achieved by the fact that the flow meter is provided with a coaxially mounted on the drain pipe and movable in the axial direction 20 relative to it by an additional pipe with an annular protrusion on the inner surface and windows under the protrusion, while the additional pipe is connected with a controlled drive.

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Claims (2)

Figure 1 shows the proposed device when measuring the flow of oil, General view; figure 2 - the second position of the pipe when measuring the flow of water; Fig. 3 shows diagrams of sensors of the KNV in the position of the VNR for measuring the flow of oil (o () and water (6)), illustrating the process of filling a controlled volume with oil or water. Flowmeter for watered oil wells consists of body 1, absolute packer; 2 pipe 3 with windows 4 and channel A, pipes 5 with annular protrusion 6 and windows 7, controlled actuator 8 connected to packer 2 and pipe 5, sensor of the field of HPR 9 (for example, moisture meter or gamma density meter) for detecting changes in the composition fluids along the wellbore in a controlled amount limited by wall of the well, branch pipe 3 and two horizontal planes (position D and position E), located relative to each other at a distance equal to the length of the measuring base of the composition sensor 9. The channel in which the VNR position sensor is installed at the top and bottom has holes F and F.-, for communication with the filling volume bounded by the borehole wall, the discharge pipe 3, the lower part of the shell of the absolute packer 2 and the horizontal plane passing through the windows 7, the discharge pipe and representing a segregation chamber (p the divisions of oil and water under the action of the force of body of tin. The controlled volume in which the composition sensor registers the change in the composition of the liquid is part of this chamber. The branch pipe 3 and the pipe 5 serve to accumulate oil under the fully opened packer, to drain the water coming from the lower intervals and from the chamber beyond the packer and displace oil and water. . The composition sensor 9 serves to monitor the filling and discharge of a controlled volume with oil. The pipe 5 with the protrusion 6 and the outlet pipe 3 form an annular channel J. The protrusion 6 alternately informs the window.4 of the branch pipe with the G channel or windows 7. Such placement of the pipe 5 prevents water from entering the windows 4 when oil is displaced from the controlled volume. The device works as follows. The flow meter is lowered into the well to a depth where it is intended to conduct the study. Upon command from the surface, a packer 2 is opened, which closes the gap between the borehole wall and the instrument body. In this case, the pipe 5 occupies the position shown in FIG. 1, i.e. the 4-pipe pipes report lower intervals at intervals located in the top of the packer 2. Since the droplets of oil in the water have lifting force, they, like the entrance windows 4 of the discharge pipe 3, accumulate under the opened packer 2 devices The segregation of oil and water and the water displaced by oil from this chamber and coming from the lower intervals along drainage channel A through windows 4 and 7 is discharged beyond the packer 2 of the device. The flow of oil from the lower intervals is determined, for example, by a known method. The filling of the chamber with oil can be determined by stopping the change in the output signal of the sensor 9 of the composition. After the chamber is filled with oil, the pipe 5 is moved to the position shown in FIG. 2. Oil and water coming from the lower intervals force oil out of the chamber. Since the well production rate is low, the speed of movement of oil droplets is approximately an order of magnitude greater than the speed of water movement and is equal to the rate of emergence of a drop of oil in still water (12-14 cm / s). Therefore, during the time t of moving the oil-liquid interface from the lower to the upper position, the volume of oil coming from the lower intervals will be added to the previously accumulated oil. Thus, the volume of oil displaced is equal to VQ + .STOr volume is displaced by the volume of water Qg-t that arrived at the same time in the lower intervals and the volume of oil Q ,, -, which arrived in a controlled, n V volume, but did not reach the moment time to reach the top position of the oil-liquid interface. The ratio for determining the water flow will be -j. c- Av. (where V is the controlled volume of the chamber; respectively, the flow of water, oil; the time of moving the oil-liquid interface; the distance between the lower and upper fixed positions of the oil-liquid interface; the speed of movement of the oil droplets; the time required to move the oil droplets from the lower to the upper fixed position of the boundaries and the oil-liquid interface. For highly water-poor low-yield wells, the value of e / vt c-f Therefore, we can assume that, Q. o "Thus, the water flow is determined by the volumetric method, whichoil flow. The volumetric method of measuring low flow rates is much more accurate than other methods (usually speed used in well flow metering. The signal size N / J indicates that the area between the D and E planes is filled with an oil-in-water emulsion, and Nj indicates that it is filled oil (Fig. 3). A change in the signal from N to N and vice versa shows a change in the position of the WRD between planes D and E. The cessation of the change in the signal of the WRD position sensor indicates that the monitored volume is filled with oil (water). The filling time of the monitored volume is taken from the diagram of the position sensor of the NVR recorded during the drawing of the diam 1 tape from the auxiliary logging drive. The use of the invention will improve the accuracy of measuring the flow of water and obtain more objective information about the nature of the fluid saturating the reservoir under study, 6 the amount of its flow, which is necessary when calculating oil reserves and controlling the development of oil fields. Claims of the Invention A downhole flowmeter for watered oil wells, comprising a housing, a packer, an outlet pipe with windows, a position of the water-oil section and a controlled actuator, characterized in that it is equipped with a coaxially mounted on the outlet pipe in order to improve the accuracy of water flow determination and an axially movable axially relative to it an additional tube with an annular protrusion on the inner surface and windows under the protrusion, wherein the additional pipe is connected to a controlled actuator. Sources of information taken into account during the examination 1. Copyright Certificate of the USSR No. 365460, cl. E 21 B 47/10, 1970 (prototype).