A FLOW-RATE MEASURING SYSTEM FOR DRILLING MUDS AND/OR FOR MULTIPHASE MIXTURES

Abstract

Disclosed is a flow-rate measuring system for drilling muds and for multiphase mixtures (water/oil/gas) also with transport of solids or sand and in the presence of heavy oil. The system includes a flow-rate measuring system for drilling muds and/or for multiphase mixtures, wherein the measuring ports are equipped with an appropriate pre-chamber that enables elimination of the risk of failure of the measuring membranes in the case of particularly erosive mixtures and in the case of presence of solid by accumulation or transport. Furthermore, the particular vertical installation enables a compactness of the system in terms of horizontal encumbrance, enables installation where there is little horizontal space, and makes possible an undisturbed flow necessary for obtaining a higher measuring accuracy. The vertical installation enables installation, on the descending stretch, of a sensor for measuring the density that renders the measuring system autonomous (normally, the density is entered as external input).

Claims

1-9. (canceled)

10. A flow-rate measuring system (1) for drilling muds and/or for multiphase mixtures, comprising a tubular body (1), wherein measuring ports (3, 4) are provided with a respective pre-chamber (5) for prevent failure of the measuring membranes (10) in the case of particularly erosive mixtures and in the case of presence of solids on the membranes by accumulation or transport; wherein, in order to prevent deposit of solids or mud-panel formation or deposit of waxes, each pre-chamber (5) is equipped with a cleaning system provided with a nozzle (9) tangential to the lateral surface of the pre-chamber for washing the pre-chamber itself, which can be operated manually or with a timed system by introducing liquid or gaseous mixtures; wherein each pre-chamber is connected to the inner of the tubular body (1) only by means of an eccentric hole which is located in correspondence of the lateral surface of the chamber itself, said eccentric hole being located at a smallest-diameter area of a longitudinal central duct (7) of said tubular body (1).

11. The measuring system (1) as per claim 10, wherein there is envisaged an arrangement of the ports for connection to the process that comprises two pairs of opposed attachments (3 and 4), set at 90° with respect to one another, for installing the measuring probes, wherein said attachments are set radially with respect to the longitudinal axis of the tubular body (1), i.e., perpendicular to the direction of the flow of the fluid to be measured, to be able to position two differential-pressure sensors (DP) with different calibrations so as to be able to extend the range of measurement of the flow rates, maintaining an optimal measuring accuracy; each of said attachments being provided with said pure-chamber (5).

12. The measuring system (1) as per claim 10, wherein, in order to reduce the overall dimensions and obtain compact dimensions, it envisages sensors (10) that make the measurement of the quantities involved in the process.

13. The measuring system (1) as per claim 10, wherein mounting of the sensors (10) on the connections—equipped with said pre-chambers (5)—to the process, is carried out via hammer unions to enable convenient maintenance of the system and speed up the possible operations of replacement of the sensors themselves.

14. The measuring system (1) as per claim 10, wherein said nozzle (9) is connected to the pre-chamber (5) via a duct, which, in the case of measurements made on multiphase mixtures of water, oil, and gas, also enables purging of the products accumulated in order to keep the pre-chamber (5) clean and maintain accuracy of measurement.

15. The measuring system (1) as per claim 10, wherein, in order to reduce the overall dimensions, it envisages a sensor system fitted into said pre-chambers (5), obtained by integrating in the separators (16) of the differential cell (13) the pressure and temperature sensors (17, 18); thus obtaining reduction of the number of connections to the process, affording compact dimensions.

16. The measuring system (1) as per claim 10, wherein a vertical installation is envisaged via a U-shaped stretch of piping (20), which is equipped with flanges (19) for connection to the ends of the stretch of horizontal piping in which the flow rate is to be measured; said flow-rate measuring system (1) being installed in one of the two branches of the U-shaped stretch of piping (20) that are set vertically.

17. The measuring system as per claim 16, wherein a densimeter (21) sensor cell within said pre-chamber (5) with cleaning system is installed on the vertical branch of the U-shaped stretch of piping (20) that is not concerned by installation of the flow-rate measuring system (1).

18. The measuring system (1) as per claim 11, wherein, in order to reduce the overall dimensions and obtain compact dimensions, it envisages sensors (10) that make the measurement of the quantities involved in the process.

19. The measuring system (1) as per claim 11, wherein mounting of the sensors (10) on the connections—equipped with said pre-chambers (5)—to the process, is carried out via hammer unions to enable convenient maintenance of the system and speed up the possible operations of replacement of the sensors themselves.

20. The measuring system ( 1) as per claim 12, wherein mounting of the sensors (10) on the connections—equipped with said pre-chambers (5)—to the process, is carried out via hammer unions to enable convenient maintenance of the system, and speed up the possible operations of replacement of the sensors themselves.

21. The measuring system (1) as per claim 11, wherein, in order to reduce the overall dimensions, it envisages a sensor system fitted into said pre-chambers (5), obtained by integrating in the separators (16) of the differential cell (13) the pressure and temperature sensors (17, 18); thus obtaining reduction of the number of connections to the process, affording compact dimensions.

22. The measuring system (1) as per claim 12, wherein, in order to reduce the overall dimensions, it envisages a sensor system fitted into said pre-chambers (5), obtained by integrating in the separators (16) of the differential cell (13) the pressure and temperature sensors (17, 18); thus obtaining reduction of the number of connections to the process, affording compact dimensions.

23. The measuring system (1) as per claim 13, wherein, in order to reduce the overall dimensions, it envisages a sensor system fitted into said pre-chambers (5), obtained by integrating in the separators (16) of the differential cell (13) the pressure and temperature sensors (17, 18); thus obtaining reduction of the number of connections to the process, affording compact dimensions.

24. The measuring system (1) as per claim 14, wherein, in order to reduce the overall dimensions, it envisages a sensor system fitted into said pre-chambers (5), obtained by integrating in the separators (16) of the differential cell (13) the pressure and temperature sensors (17, 18); thus obtaining reduction of the number of connections to the process, affording compact dimensions.

25. The measuring system (1) as per claim 11, wherein a vertical installation is envisaged via a U-shaped stretch of piping (20), which is equipped with flanges (19) for connection to the ends of the stretch of horizontal piping in which the flow rate is to be measured; said flow-rate measuring system (1) being installed in one of the two branches of the U-shaped stretch of piping (20) that are set vertically.

26. The measuring system (1) as per claim 12, wherein a vertical installation is envisaged via a U-shaped stretch of piping (20), which is equipped with flanges (19) for connection to the ends of the stretch of horizontal piping in which the flow rate is to be measured; said flow-rate measuring system (1) being installed in one of the two branches of the U-shaped stretch of piping (20) that are set vertically.

27. The measuring system (1) as per claim 13, wherein a vertical installation is envisaged via a U-shaped stretch of piping (20), which is equipped with flanges (19) for connection to the ends of the stretch of horizontal piping in which the flow rate is to be measured; said flow-rate measuring system (1) being installed in one of the two branches of the U-shaped stretch of piping (20) that are set vertically.

28. The measuring system (1) as per claim 14, wherein a vertical installation is envisaged via a U-shaped stretch of piping (20), which is equipped with flanges (19) for connection to the ends of the stretch of horizontal piping in which the flow rate is to be measured; said flow-rate measuring system (1) being installed in one of the two branches of the U-shaped stretch of piping (20) that are set vertically.

29. The measuring system (1) as per claim 15, wherein a vertical installation is envisaged via a U-shaped stretch of piping (20), which is equipped with flanges (19) for connection to the ends of the stretch of horizontal piping in which the flow rate is to be measured; said flow-rate measuring system (1) being installed in one of the two branches of the U-shaped stretch of piping (20) that are set vertically.

Description

IN THE DRAWINGS

[0020] FIG. 1, 1A, and 1B are, respectively, a side elevation of the invention, an axial cross-sectional view, and an axial cross-sectional view with the sensor installed;

[0021] FIG. 2 is a top plan view of the invention;

[0022] FIG. 3 is a partially sectioned top plan view;

[0023] FIG. 4, which is similar to FIG. 3, shows a sensor installed;

[0024] FIG. 5 is a side view that shows two sensors connected to the differential cell;

[0025] FIG. 6 snows an enlarged detail of the measuring membrane (or diaphragm), with the temperature sensor, the pressure sensor, and the capillary tube for the differential cell;

[0026] FIG. 7 is a top plan view corresponding to that of FIG. 5;

[0027] FIG. 8 shows the invention mounted along a piping, with all the sensors installed;

[0028] FIG. 9 shows the invention installed with a particular configuration, with vertical mounting in a horizontal piping; and

[0029] FIG. 10, which is similar to the previous one, shows the invention installed in series on a dynamic density meter.

DESCRIPTION OF AN EXAMPLE OF EMBODIMENT OF THE INVENTION

[0030] The attached figures are cross-sectional views of the invention and show the layout of the sensor system and the peculiar vertical installation, with measurement of fluid density. In addition, the compensation pre-chambers and the washing nozzles are clearly indicated.

[0031] With reference to the figures, the invention is basically constituted by a body 1 comprising a longitudinal stretch of piping 7 equipped with inlet end attachments 2I, and outlet end attachments 2U, of the flanged (or weld or clamp) type, for fixing to the piping flowing in which is the fluid the flow rate of which is to be measured.

[0032] In the part of the body 1, towards the inlet end flange 2I, two pairs of opposed attachments 3 and 4 are provided, set at 90° apart, for installing the measuring probes, wherein said attachments are set radially with respect to the longitudinal axis of the tubular body 1, i.e., perpendicular to the direction of the flow of the fluid to be measured.

[0033] According to a peculiar characteristic of the invention, provided inside each of said attachments 3 and 4, which are preferably of the wing-union type or of some other type required by the specific installation, is a measuring chamber 5 (also referred to as “pre-chamber”) with spoked/chamfered bottom 6, which is in turn connected to the longitudinal central duct 7 with single or multiple pressure ports 8 (FIG. 3).

[0034] A further peculiar characteristic of the invention lies in the fact that provided in the proximity of the bottom of each of the measuring chambers 5 is a tangential port 9 for washing/purging of the chamber itself.

[0035] With reference to FIG. 4, the device according to the invention is illustrated with a measuring probe installed, with sensors having a measuring membrane 10 inserted in the measuring chamber 5, fixed in position via a ring-nut 11 of a hammer-union type, equipped with a capillary tube 12 for connection to the differential cell 13, which is in turn connected to the measuring probe with membrane sensors 10 installed in the adjacent attachment that is perpendicular to the previous one (FIG. 8).

[0036] Each measuring probe is equipped with amplifiers 14 and a connector with plug 15. Moreover, the end of the probe provided with measuring membrane 10 is also equipped with capillary tube 16 for the differential cell 13, with a temperature sensor 17, and with a pressure sensor 18 (FIGS. 5, 6, and 7).

[0037] More specifically, as may be seen in FIG. 6, each membrane 10 makes a measurement of pressure, temperature, and differential pressure (DP). Altogether, two membranes make five measurements (DP is one for two membranes). In the dual-range solution illustrated in the figures, membranes 10 are four for ten measurements.

[0038] In addition, it should be noted that, envisaging the use of hammer unions, the operations of maintenance of the system are facilitated, and any possible replacement of the sensors, which are basically constituted by just two measuring membranes 10 for five measurements, is speeded up.

[0039] Among the peculiar characteristics of the invention, the following are to be pointed out:

[0040] compactness of the system;

[0041] presence of an insert made of special material for increasing resistance to erosion;

[0042] compensation chambers connected to the process with one or more holes;

[0043] multi-parametric membrane sensors that in one and the same membrane measure P, T, and DP;

[0044] redundancy of the measurement and hence reliability;

[0045] extended range of the measurement with dual DP in a compact system;

[0046] tangential-washing system;

[0047] purging system;

[0048] autonomous washing system timed on the basis of the pressures and the type of mud, as well as the tendency of the latter to form a panel within a pre-determined period of time;

[0049] presence of two measuring apparatuses that work simultaneously, ensuring continuity of the measurement also in the case of partial damage to the sensor system;

[0050] time interval for washing the pre-chamber that can be managed via a timer or other similar device; and

[0051] with reference to the two previous points, a smart software that can advantageously be provided for intervening in the event of failure of a differential cell and for calculating the time for washing the pre-chamber.

[0052] With reference to FIG. 9, another interesting aspect of the invention is represented by the fact that, even though the installation can be carried out in a horizontal, vertical, or inclined configuration in the case where the plant line presents little horizontal space for installation of a Venturi meter, a vertical installation is envisaged via a purposely designed U-shaped stretch of piping 20, which is equipped with a flange 19 for connection to the ends of the stretch of horizontal piping in which the flow rate is to be measured. In this case, the flow-rate measuring system described is installed in one of the two branches of the U-shaped stretch of piping 20, which are set vertically.

[0053] Advantageously, with this arrangement, even though the stretch of horizontal piping available in the plant has a length insufficient for enabling installation of a Venturi meter, it is possible to overcome this problem by providing, in the horizontal space effectively available, a vertical stretch of piping having a length sufficient for installation of the flow-rate measuring system 1 according to the invention.

[0054] A further advantage is represented by the fact that, in the case referred to above, where a purposely designed U-shaped stretch of piping 20 is installed, the vertical branch of the U-shaped stretch of piping that is not concerned by installation of the flow-rate measuring system 1, can advantageously be used for carrying out the measurement of density, installing thereon a densimeter 21, which, as is known, uses a differential cell for measuring DP, which cannot be installed on horizontal lines.

[0055] Yet a further advantage of the invention lies in the fact that, in the case where the aforesaid U-shaped stretch of piping is used, measurements of fluid flow rates and possibly of fluid density can be made, eliminating the problems that might arise from installation in stretches of piping where there are marked variations of the cross section or other problems that might jeopardize the validity of the measurement itself. In this connection, it should be noted that, in the piping of plants, the presence of convergence, divergence, or bends gives rise to formation of a flow that is not stabilized and of turbulence that causes major measurement errors. Frequently, modifications to the lines are made without taking into account the problems created for the flow. Installation of the device according to the invention via the aforesaid U-shaped stretch of piping avoids these problems.

[0056] Finally, it should be noted that the specific Venturi design of the internal path of the flow and the external machining, combined with a positioning at 90° of the measuring chambers with a specific positioning of the ducts for communication with the current of the main flow, as well as the specific use of the pressure hammer unions, are all characteristics that—combined together according to the present invention—enable provision of a compact unit (for example, a length of just 650 mm for a 5″ XXS pipe for pressures of up to 10 000 psi—10 kpsi CWP and up to 10 variables detected) to be placed on a drilling platform where the space is always extremely limited and where standard and cumbersome installations might not be acceptable from the technical standpoint. Moreover this would mean rather high production costs.

LEGEND

[0057] 1. Venturi tube obtained from a bar for measurement of flow rate, complete with dual differential port

[0058] 2I, 2U. Flanged/weld/clamp attachment

[0059] 3, 4. Attachments (of the wing-union type or else as required)

[0060] 5. Measuring chamber

[0061] 6. Spoked/chamfered bottom

[0062] 7. Venturi tube for passage of fluid

[0063] 8. Single or multiple pressure port

[0064] 9. Tangential-washing and purging system for each measuring chamber (manual or automatic)

[0065] 10. Measuring membrane

[0066] 11. Figure 1502 hammer union

[0067] 12. Capillary tube for connection of DP cell to separators

[0068] 13. Differential cell

[0069] 14. Amplifiers

[0070] 15. Connector with plug

[0071] 16. Capillary tube for differential cell

[0072] 17. Temperature sensor

[0073] 18. Pressure sensor

[0074] A. Venturi tube and multiparametric probes—vertical installation

[0075] B. Dynamic density meter integrated in the Venturi-tube flowmeter