HYDRAULICS MODEL UTILIZATION IN WELL OPERATIONS

Abstract

A method of utilizing a hydraulics model with a well operation can include the steps of inputting well parameters to the hydraulics model, assigning nodes to respective well locations, the hydraulics model being configured to determine corresponding pressures at the respective nodes, and unevenly spacing the nodes along a wellbore. A well equipment control system for use with a subterranean well can include a hydraulics model configured to determine pressures at respective nodes along a wellbore, the nodes being unevenly spaced along the wellbore, and an actuator configured to actuate well equipment at least in part based on the hydraulics model pressure determinations.

Description

BACKGROUND

This disclosure relates generally to equipment utilized and operations performed in conjunction with a subterranean well and, in examples described below, more particularly provides for improved utilization of hydraulics models in well operations.

In a variety of different types of well operations (such as, drilling, cementing, fracturing, gravel packing, stimulating, conformance, etc.), it is useful to be able to determine fluid pressures at downhole locations. A hydraulics model is a software application that can receive sensor readings and other types of input, and produce determinations of fluid pressures at downhole locations.

It will, therefore, be readily appreciated that improvements are continually needed in the art of utilizing hydraulics models in well operations. These improvements can result in increased production, efficiency, cost-effectiveness, etc., and reduced costs, unproductive time, fluid loss or fluid influxes, etc., in the well operations.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a representative partially cross-sectional view of an example of a well system and associated method which can embody principles of this disclosure.

FIG. 2 is a representative schematic of a well equipment control system which can embody the principles of this disclosure.

FIG. 3 is a representative flowchart for a method of utilizing a hydraulics model in a well operation.

FIG. 4 is a representative cross-sectional view of a wellbore with uneven hydraulics model node spacings.

DETAILED DESCRIPTION

The following detailed description and accompanying drawing FIGS. 1-4 describe and depict examples of a method 60 of utilizing a hydraulics model 48 with a well operation. In one example (see FIG. 3), the method 60 can comprise the steps of inputting well parameters to the hydraulics model 48; assigning nodes 70 to respective well locations, the hydraulics model 48 being configured to determine corresponding pressures at the respective nodes 70; and unevenly spacing the nodes 70 along a wellbore 14.

The unevenly spacing step may include providing a greater density of the nodes 70 along the wellbore 14 in a first wellbore section 14a as compared to a second wellbore section 14b. The unevenly spacing step may include providing a lesser distance A between the nodes in a first wellbore section 14a as compared to a second wellbore section 14b. The first wellbore section 14a may include at least one of an open hole portion of the wellbore and an under-pressured formation zone 72.

The method may include controlling operation of well equipment 42, based on the pressure determinations. The well equipment 42 may include a choke 36, and the controlling step may include adjusting the choke.

The method may include installing the hydraulics model 48 in a programmable logic controller 46. The programmable logic controller 46 may control operation of well equipment 42, based on the pressure determinations.

The hydraulics model 48 may automatically assign the nodes 70 to the respective well locations and unevenly space the nodes along the wellbore 14, based at least in part on the input well parameters.

Also provided by the present disclosure are examples of a well equipment control system 40 for use with a subterranean well. In one example (see FIG. 2), the well equipment control system 40 can comprise a hydraulics model 48 configured to determine pressures at respective nodes 70 along a wellbore 14, the nodes being unevenly spaced along the wellbore; and an actuator 44 configured to actuate well equipment 42 at least in part based on the hydraulics model 48 pressure determinations.

The well equipment control system 40 may include a programmable logic controller 46 configured to control operation of the actuator 44. The hydraulics model 48 may be installed in the programmable logic controller 46.

A spacing A between the nodes 70 in a first section 14a of the wellbore 14 may be less than a spacing B between the nodes in a second section 14b of the wellbore. A density of the nodes 70 in a first section 14a of the wellbore 14 may be greater than a density of the nodes in a second section 14b of the wellbore. The first section 14a of the wellbore 14 may include an open hole section of the wellbore, or an under-pressured formation zone 72.

The well equipment 42 may include a choke 36.

Representatively illustrated in FIG. 1 is a system 10 for use with a subterranean well, and an associated method, which can embody principles of this disclosure. However, it should be clearly understood that the system 10 and method are merely one example of an application of the principles of this disclosure in practice, and a wide variety of other examples are possible. Therefore, the scope of this disclosure is not limited at all to the details of the system 10 and method described herein and/or depicted in the drawings.

In the FIG. 1 example, a tubular string 12 is positioned in a wellbore 14. The tubular string 12 is a drill string having a drill bit 16 connected at a distal end thereof for the purpose of drilling into the earth. In other examples, the tubular string 12 could be a work string, a stimulation string, a completion string, an injection string, a production string, or another type of tubular string. The scope of this disclosure is not limited to use of any particular type of tubular string in a well, or to use of a tubular string at all.

As depicted in FIG. 1, a pump 18 is used to maintain a fluid flow 20 through the tubular string 12 in the wellbore 14. In this example, the fluid flow 20 enters the tubular string 12 at the surface via a standpipe 22, which may be connected to the tubular string via a top drive, a kelly, or other equipment (not shown). The fluid flow 20 exits the tubular string 12 in the wellbore 14 via nozzles (not shown) in the drill bit 16.

The fluid flow 20 returns to the surface via an annulus 24 formed between the tubular string 12 and the wellbore 14. In managed pressure drilling operations, the annulus 24 may be isolated from the atmosphere at the surface by well equipment 26 known to those skilled in the art as a rotating control device, rotating drilling head, rotating blowout preventer, rotating control head, etc. In well control operations, the well equipment 26 may be an annular blowout preventer, pipe rams, or other equipment. However, the scope of this disclosure is not limited to use of any well equipment to isolate an annulus from the atmosphere at the surface.

The returned fluid flow 20 may pass through a choke manifold 28 (typically comprising multiple chokes 36) and various types of fluid conditioning equipment 30 (such as, a gas separator, a shale shaker, etc.) prior to flowing into a reservoir 32 (also known as a “mud pit”). The pump 18 draws fluid from the reservoir 32. Note that the FIG. 1 example is simplified for purposes of clarity of illustration and description, and those skilled in the art will appreciate that additional equipment or different equipment may be used, depending in part on the particular well operation being performed.

In the FIG. 1 example, a rheology measurement apparatus 34 is connected between the pump 18 and the tubular string 12. Thus, the fluid flow 20 exiting the pump 18 passes through the rheology measurement apparatus 34 and then the standpipe 22 prior to entering the tubular string 12. In this manner, rheological parameters of the fluid flow 20 (and other characteristics, such as, volumetric and mass flow rate, density, other, etc.) can be accurately measured as it is being introduced into the well. In some examples, another rheology measurement apparatus may also measure characteristics of the fluid flow 20 after it exits the well (such as, connected upstream or downstream of the choke manifold 28).

The FIG. 1 system 10 can include any of various well equipment control system 40 examples described herein (see FIG. 2). The well equipment control system 40 can be used to provide determinations of pressures at respective downhole locations, with the locations being unevenly spaced along the wellbore 14. For example, a closer, more dense spacing of the locations can be used in sections of the wellbore 14 that are more important or problematic, and less dense spacing of the locations can be used in sections of the wellbore that are less important or problematic.

Referring additionally now to FIG. 2, a schematic example of a well equipment control system 40 is representatively illustrated. For convenience, the well equipment control system 40 is described below as it may be used with the well drilling operation, system 10 and method of FIG. 1, but in other examples the well equipment control system can be used with other well operations, systems and methods.

In the FIG. 2 example, the control system 40 is used to control operation of one or more items of well equipment 42. The well equipment 42 may be the pump 18, a choke 36 (e.g., part of the FIG. 1 choke manifold 28), the equipment 26 and/or the fluid conditioning equipment 30. Other types and combinations of well equipment may be controlled using the control system 40 in keeping with the scope of this disclosure.

The FIG. 2 well equipment 42 is actuated by an actuator 44. The actuator 44 may be an electrical, hydraulic, mechanical, or other type of actuator. The scope of this disclosure is not limited to use of any particular type of actuator, or to use of an actuator at all.

A programmable logic controller 46 controls operation of the actuator 44 in the FIG. 2 example. The programmable logic controller 46 operates the actuator 44 to cause a desired change in configuration or mode of operation of the well equipment 42. For example, if it is desired to reduce a restriction to the fluid flow 20 through the choke 36 (e.g., to cause a corresponding reduction in pressure in the wellbore 14), the programmable logic controller 46 can operate the actuator 44 to cause a trim (not shown) in the choke to displace to a position in which the fluid flow is less restricted.

In the FIG. 2 control system 40, a hydraulics model 48 is installed in the programmable logic controller 46. In this example, the hydraulics model 48 comprises software code configured to provide predictions or determinations of pressure at each of various downhole locations or “nodes,” in response to input of relevant well parameters to the hydraulics model. Such well parameters may include the wellbore 14 geometry, mud weight (density), flow rate into and out of the wellbore, pump 18 strokes, temperature, standpipe 22 pressure, annulus 24 pressure, fluid rheology, etc.

Certain well parameters may be input to the hydraulics model 48 continuously or periodically during the well operation, so that the hydraulics model can provide the pressure predictions or determinations in real time during the well operation. Certain well parameters may be input to the programmable logic controller 46 and the hydraulics model 48 manually (such as, using a workstation 50) or automatically (such as, readings or measurements taken by pressure sensors 52, flowmeters 54, temperature sensors 56 or the rheology measurement apparatus 34 described above).

The hydraulics model 48 can provide the predictions or determinations of pressure for each of multiple downhole locations or nodes. A node is a pressure simulation point or location along a wellbore at which a hydraulics model will provide determinations of pressure based on current conditions, or will provide predictions of pressure based on given future conditions.

In this example, the hydraulics model 48 is configured to allow the nodes along the wellbore 14 to be defined at any locations. Thus, uneven spacing of the nodes along the wellbore 14 is permitted. Spacings between the nodes can be selected manually (such as, by an operator) or automatically (such as, by the hydraulics model 48 based, for example, on certain input well parameters).

For example, it may be desirable to have smaller spacing between the nodes in important or problematic sections of the wellbore 14, and larger spacing between the nodes in less important or problematic sections of the wellbore. The smaller spacing (and greater density in number of nodes per unit length) provides increased pressure profile granularity and resolution, and the larger spacing (less density) provides reduced computational burden. Examples of important or problematic wellbore sections include (but are not limited to) open hole sections, under-pressured formation zones, wellbore junctions, sections in which pressure anomalies are expected, etc.

Note that, although the hydraulics model 48 is described above as being configured to provide determinations of pressure at each of multiple downhole locations, the hydraulics model can also perform any of a wide variety of other functions. For example, the hydraulics model 48 could provide determinations of temperature or flow rate at the respective nodes, or provide alerts for fluid loss or fluid influxes downhole. Therefore, the scope of this disclosure is not limited to any particular functions or combination of functions performed by the hydraulics model 48.

Referring additionally now to FIG. 3, a flowchart for an example of a method 60 of utilizing a hydraulics model with a well operation is representatively illustrated. The method 60 is described below as it may be used with the well system 10 and well equipment control system 40 described above, but it should be understood that the method 60 may be used with other well systems and well equipment control systems.

In step 62, well parameters are input to the hydraulics model 48. The well parameters may include the wellbore 14 geometry, mud weight (density), flow rate into and out of the wellbore, pump 18 strokes, temperature, standpipe 22 pressure, annulus 24 pressure, fluid rheology, open hole sections, cased hole sections, under-pressured formation zones, wellbore junctions, any other important or problematic sections, etc. The well parameters may be input manually (such as, using the workstation 50) and/or automatically (such as, by transmitting readings or measurements to the hydraulics model 48 from the sensors 34, 52, 54, 56).

In step 64, nodes are assigned to specific respective locations along the wellbore 14. The nodes can be unevenly spaced, so that there is a greater density or less space between the nodes in some sections of the wellbore 14 (such as, important or problematic sections), and less density or greater space between the nodes in other sections of the wellbore (such as, relatively unimportant or non-problematic sections).

Note that it is not necessary for the density or spacing between nodes in a given section of the wellbore 14 to be consistent. There can be variations in density or spacing between nodes in a section of the wellbore 14.

The assigning of nodes to respective wellbore 14 locations may be accomplished manually (such as, via the workstation 50) or automatically by the hydraulics model 48 (based, for example, on known important or problematic sections entered via the workstation).

In step 66, the hydraulics model 48 determines the pressures at the respective nodes, based on the input well parameters. Preferably, the hydraulics model 48 provides the pressure determinations in real time, based in part on real time readings and measurements from the sensors 34, 52, 54, 56.

In some examples, the hydraulics model 48 can also provide predicted pressures at the respective nodes, based on given future well parameters. The predicted pressures can assist with planning the future course of a well operation, for example, deciding whether to take a particular action in the well operation.

In step 68, the well operation is performed while the hydraulics model 48 is determining the pressures at the respective nodes. The hydraulics model 48 can be used to monitor the well operation and/or to assist with planning what actions to take in the future. The well operation may comprise drilling, cementing, fracturing, gravel packing, stimulating, conformance or other types of well operations.

In some examples, the hydraulics model 48 provides a pressure set point appropriate for the ongoing well operation for use in controlling the well equipment 42. For example, in the FIG. 1 system 10, the pressure set point could be a desired pressure in the standpipe 22 or annulus 24 at the surface to achieve a desired pressure downhole.

The programmable logic controller 46 uses the pressure set point to control operation of the well equipment 42, so that differences between the actual measured pressure and the pressure set point are minimized. For example, the programmable logic controller 46 can control operation of the actuator 44 to increase or decrease a restriction to the fluid flow 20 through the choke 36 to thereby produce a desired respective increase or decrease in pressure in the wellbore 14.

Referring additionally now to FIG. 4, a cross-sectional view of an example of adjacent sections 14a, 14b of the wellbore 14 is representatively illustrated. In this example, the wellbore section 14a is an open hole or uncased section of the wellbore 14, and the wellbore section 14b is a cased section of the wellbore.

It is desired in this example to obtain enhanced resolution and granularity of pressure determinations in the wellbore section 14a. However, such enhanced resolution and granularity is not needed or desired for the wellbore section 14b.

In order to achieve the desired enhanced resolution and granularity, nodes 70 are defined in the wellbore section 14a, so that a spacing A between the nodes is sufficiently small. A spacing B between the nodes 70 in the wellbore section 14b is greater than the spacing A between the nodes in the wellbore section 14a. A density of the nodes 70 (number of nodes per unit distance along the wellbore 14) in the wellbore section 14a is greater than the density of the nodes in the wellbore section 14b.

In addition to the wellbore section 14a being open hole, it could also or alternatively be in an under-pressured formation zone 72, a wellbore junction, or another important or problematic wellbore section. The scope of this disclosure is not limited to any particular reason for defining the nodes 70 at their respective locations along the wellbore 14, or for unevenly spacing the nodes along the wellbore.

Although various examples have been described above, with each example having certain features, it should be understood that it is not necessary for a particular feature of one example to be used exclusively with that example.

Instead, any of the features described above and/or depicted in the drawings can be combined with any of the examples, in addition to or in substitution for any of the other features of those examples. One example's features are not mutually exclusive to another example's features. Instead, the scope of this disclosure encompasses any combination of any of the features.

Although each example described above includes a certain combination of features, it should be understood that it is not necessary for all features of an example to be used. Instead, any of the features described above can be used, without any other particular feature or features also being used.

It should be understood that the various embodiments described herein may be utilized in various orientations, such as inclined, inverted, horizontal, vertical, etc., and in various configurations, without departing from the principles of this disclosure. The embodiments are described merely as examples of useful applications of the principles of the disclosure, which is not limited to any specific details of these embodiments.

In the above description of the representative examples, directional terms (such as “above,” “below,” “upper,” “lower,” “upward,” “downward,” etc.) are used for convenience in referring to the accompanying drawings. However, it should be clearly understood that the scope of this disclosure is not limited to any particular directions described herein.

The terms “including,” “includes,” “comprising,” “comprises,” and similar terms are used in a non-limiting sense in this specification. For example, if a system, method, apparatus, device, etc., is described as “including” a certain feature or element, the system, method, apparatus, device, etc., can include that feature or element, and can also include other features or elements. Similarly, the term “comprises” is considered to mean “comprises, but is not limited to.”

Of course, a person skilled in the art would, upon a careful consideration of the above description of representative embodiments of the disclosure, readily appreciate that many modifications, additions, substitutions, deletions, and other changes may be made to the specific embodiments, and such changes are contemplated by the principles of this disclosure. For example, structures disclosed as being separately formed can, in other examples, be integrally formed and vice versa. Accordingly, the foregoing detailed description is to be clearly understood as being given by way of illustration and example only, the spirit and scope of the invention being limited solely by the appended claims and their equivalents.

Claims

1. A method of utilizing a hydraulics model with a well operation, the method comprising: inputting well parameters to the hydraulics model;assigning nodes to respective well locations, the hydraulics model being configured to determine corresponding pressures at the respective nodes; andunevenly spacing the nodes along a wellbore.

2. The method of claim 1, in which the unevenly spacing comprises providing a greater density of the nodes along the wellbore in a first wellbore section as compared to a second wellbore section.

3. The method of claim 2, in which the first wellbore section comprises at least one of the group consisting of an open hole portion of the wellbore and an under-pressured formation zone.

4. The method of claim 1, in which the unevenly spacing comprises providing a lesser distance between the nodes in a first wellbore section as compared to a second wellbore section.

5. The method of claim 4, in which the first wellbore section comprises at least one of the group consisting of an open hole portion of the wellbore and an under-pressured formation zone.

6. The method of claim 1, further comprising controlling operation of well equipment, based on the pressure determinations.

7. The method of claim 6, in which the well equipment comprises a choke, and the controlling comprises adjusting the choke.

8. The method of claim 1, further comprising installing the hydraulics model in a programmable logic controller.

9. The method of claim 8, in which the programmable logic controller controls operation of well equipment, based on the pressure determinations.

10. The method of claim 1, in which the hydraulics model automatically assigns the nodes to the respective well locations and unevenly spaces the nodes along the wellbore, based at least in part on the input well parameters.

11. A well equipment control system for use with a subterranean well, the well equipment control system comprising: a hydraulics model configured to determine pressures at respective nodes along a wellbore, the nodes being unevenly spaced along the wellbore; andan actuator configured to actuate well equipment at least in part based on the hydraulics model pressure determinations.

12. The well equipment control system of claim 11, further comprising a programmable logic controller configured to control operation of the actuator.

13. The well equipment control system of claim 12, in which the hydraulics model is installed in the programmable logic controller.

14. The well equipment control system of claim 11, in which a spacing between the nodes in a first section of the wellbore is less than a spacing between the nodes in a second section of the wellbore.

15. The well equipment control system of claim 14, in which the first section of the wellbore comprises an open hole section of the wellbore.

16. The well equipment control system of claim 14, in which the first section of the wellbore comprises an under-pressured formation zone.

17. The well equipment control system of claim 11, in which a density of the nodes in a first section of the wellbore is greater than a density of the nodes in a second section of the wellbore.

18. The well equipment control system of claim 17, in which the first section of the wellbore comprises an open hole section of the wellbore.

19. The well equipment control system of claim 17, in which the first section of the wellbore comprises an under-pressured formation zone.

20. The well equipment control system of claim 11, in which the well equipment comprises a choke.