LANDING INDICATOR FOR LOGGING TOOLS

Abstract

An apparatus for evaluating an earth formation intersected by a wellbore may include a logging tool conveyed into the wellbore through a drilling tubular, a landing indicator associated with the logging tool, and a sensor operatively associated with the logging tool. In use, the landing indicator generates a pressure pulse in the drilling tubular after contacting a travel restrictor positioned in the drilling tubular. After the logging tool is positioned at the target depth, the sensor makes at least one measurement while the logging tool is in the drilling tubular and provides an output indicative of a selected subsurface parameter.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

None.

BACKGROUND OF THE DISCLOSURE

1. Field of the Disclosure

This disclosure relates generally to logging a well during tripping of a drill string.

2. Background of the Art

Oil or gas wells are often logged to determine one or more geological, petrophysical, geophysical, and well production properties (“parameters of interest”) using electronic measuring instruments conveyed along a wellbore. Tools adapted to perform such surveys are sometimes referred to as logging tools. These tools may use electrical, acoustical, nuclear and/or magnetic energy to investigate a formation traversed by the wellbore. Well logging can be performed at various stages of well construction. In some aspects, the present disclosure relates to logging tools that may be used while a drill string is tripped out of the wellbore.

SUMMARY OF THE DISCLOSURE

In aspects, the present disclosure provides an apparatus for use in a wellbore. The apparatus may include a tool conveyed into the wellbore through a drilling tubular, a landing indicator associated with the tool that generates a pressure pulse in the drilling tubular after contacting a travel restrictor positioned in the drilling tubular, and a sensor associated with the tool that estimates at least one selected subsurface parameter while the tool is in the drilling tubular.

In aspects, the present disclosure provides a method of using a tool in a wellbore. The method may include estimating at least one subsurface parameter using a sensor associated with a tool after receiving a pressure pulse generated by a landing indicator associated with the tool, wherein the landing indicator generates the pressure pulse in response to contact with a travel restrictor in the drilling tubular.

In aspects, the present disclosure further provides an apparatus for use in a wellbore. The tool may be configured to be conveyed into the wellbore and have a landing indicator that generates a pressure pulse in a fluid column in the wellbore after contacting a travel restrictor positioned in the wellbore.

Examples of certain features of the disclosure have been summarized rather broadly in order that the detailed description thereof that follows may be better understood and in order that the contributions they represent to the art may be appreciated. There are, of course, additional features of the disclosure that will be described hereinafter and which will form the subject of the claims appended hereto.

BRIEF DESCRIPTION OF THE DRAWINGS

For a detailed understanding of the present disclosure, reference should be made to the following detailed description of the embodiments, taken in conjunction with the accompanying drawings, in which like elements have been given like numerals, wherein:

FIG. 1 illustrates a drilling system made in accordance with one embodiment of the present disclosure;

FIG. 2 schematically illustrates a logging while tripping device made in accordance with one embodiment of the present disclosure;

FIG. 3 illustrates a landing indicator made in accordance with one embodiment of the present disclosure; and

FIGS. 4 & 5 illustrate successive stages of activation of the FIG. 3 embodiment of a landing indicator.

DETAILED DESCRIPTION OF THE DISCLOSURE

Aspects of the present disclosure provide a landing indicator that signal when a logging tool has landed at a target location in a wellbore. In some arrangements, the landing indicator is attached to a logging tool and is actuated by contact with a feature that obstructs axial travel along a bore of a drill string. The travel restricting feature may be disposed at a selected location along the bore of a drill string; e.g., at a bottom end of a drill string. In response to contact with the travel restricting feature, the landing indicator generates a discernable short-duration pressure spike in a fluid column inside the drill string. This pressure spike indicates to personnel that the logging tool has landed at the target location.

Landing indicators in accordance with the present disclosure may be used to accurately position a logging tool at a target location inside an umbilical associated with a drilling system adapted to form a wellbore. Referring now to FIG. 1, there is schematically illustrated one such drilling system 10 for forming a wellbore 12 in an earthen formation 13. While a land-based rig is shown, these concepts and the methods are equally applicable to offshore drilling systems. Also, the wellbore 12 may include vertical sections, deviated sections, and horizontal sections, as well as branch wellbores. The drilling system 10 may use a bottomhole assembly (BHA) 14 conveyed by an umbilical such as a drill string 16 suspended from a rig 18. The drill string 16 may include a drill bit 20 at a distal end. The drill string 16 may be include any known drilling tubular adapted for use in a wellbore, e.g., jointed drill pipe, coiled tubing, casing, liner, etc.

For a variety of reasons, the drill string 16 may be “tripped” out of a wellbore. As used herein, the term “trip” or “tripping” refers to movement of the drill string 16 along the wellbore 12; e.g., “tripping out” refers to extraction of the drill string 16 from a wellbore 12. For instance, the drilling may be completed or drill string equipment may need repair/replacement. During these situations, an accurately positioned logging tool 50, shown in hidden lines, may be used to acquire information relating to the wellbore 12 and/or formation 13 while the drill string 16 is tripped out of the wellbore 12.

FIG. 2 illustrates the exemplary components of a logging tool 50 that may be used to log a well while the drill string 16 is tripped out of the wellbore 12. The logging tool 50 is shown positioned inside a portion of the drill string 16 and at the target location. In the embodiment shown, the logging tool 50 includes a power section 52, a controller 54 for operating the logging tool 50, and a sensor section 56 for logging the well. These components may be inside one unitary structure, within separate interconnected modules, or otherwise associated with the logging tool 50. The power section 52 may include resident electrical power sources such as batteries to energize the components of the logging tool 50. The controller 54 may include information processing devices such as processors programmed with instructions and memory modules for storing information acquired during the logging activity.

The sensor section 56 includes instruments for estimating parameters of interest relating to one or more selected subsurface features such as the formation 13 and/or the wellbore 12. In some embodiments of the present disclosure, the logging tool 50 resides inside of the drill string 16. Thus, the sensor section 56 may include instruments that can measure wellbore or formation properties through a wall of a wellbore tubular such as the drill string 16 or casing (not shown), including but limited to pulsed neutron logging tools, neutron porosity tools using chemical neutron sources, cased hole resistivity tools, or acoustic tools. However, it should be appreciated that the teachings of the present disclosure are not limited to any specific types of instruments. Thus, the sensor section 56 may include resistivity tools, nuclear magnetic resonance (NMR) tools, and other well logging tools that provide information relating to a geological parameter, a geophysical parameter, a petrophysical parameter, and/or a lithological parameter. The sensor section 56 may include sensors that output signals representative of a sensed parameter and sources (e.g., pulsed neutrons) that emit an energy wave into the formation 13. Other illustrative instruments used in the sensor section 56 may estimate dielectric constant, the presence or absence of hydrocarbons, acoustic porosity, bed boundary, formation density, nuclear porosity and certain rock characteristics, permeability, capillary pressure, and relative permeability. The tools may also estimate wellbore parameters such as inclination, azimuth, wellbore diameter, rugosity, etc. These parameters collectively will be referred to as “subsurface” parameters.

As is known, the information obtained by the sensor section 56 should be correlated with depth along the wellbore 12 in order to properly characterize the formation. Therefore, it is desirable to position the logging tool 50 at a reference depth in the wellbore 12 to enable an accurate correlation between the obtained information and well depth. Thus, the logging tool 50 includes a landing indicator 60 that signals to the surface that logging tool 50 has reached the reference depth, or target depth, in the wellbore 12. In some embodiments, the target depth may be a location proximate to the drill bit 20 (FIG. 1) or BHA 14 (FIG. 1). In general, the target depth may be any known location along the drill string 16.

In one embodiment, the landing indicator 60 is configured to generate a unique and discernable pressure pulse after the logging tool 50 reaches the target depth. As will be described below, the landing indicator 60 interferingly contacts a travel restrictor 26 that has been fixed at a desired location in the drill string 16. A travel restrictor 26 may be any device that projects radially inwardly into the drill string bore 24 and presents one or more surfaces that block passage of all or a portion of the logging tool 50. For example, the travel restrictor 26 may be a baffle plate that is interconnected between two jointed tubulars. When actuated by contact with the travel restrictor 26, the landing indicator 60 temporarily restricts flow and thereby generates a pressure pulse in a fluid column in the drill string bore 24. Pressure transducers, or other pressure detectors, in communication with the fluid column in the drill string bore 24 may be used to detect this pressure pulse.

Referring now to FIG. 3, in one embodiment, the landing indicator 60 may include a sliding sleeve 62 that is mounted on a mandrel 64 in a telescopic fashion. The mandrel 64 has an upper section 66 and a lower section 68. Initially, the sliding sleeve 62 is disposed around the upper section 66 and fixed to the mandrel 64 using frangible elements such as shear screws 70. The annular space 72 between the sliding sleeve 62 and the upper section 66 is sized to receive a flow dam 74. The upper section 66 may include a collared end 76 that secure the mandrel 64 to a connector 78. The connector 78 may be an intermediate sub or other linking device that couples the landing indicator 60 to the logging tool 50. Of course, the landing indicator 60 may be associated with the logging tool 50 using other structural arrangements as well. The lower section 68 includes an engagement head 80 that has a diameter greater than an inner diameter of the travel restrictor 26.

The sliding sleeve 62 may be configured to selectively release the flow dam 74 after the landing indicator 60 reaches the target depth. In one embodiment, the sliding sleeve 62 may be a tubular member having one or more swab cups 82 affixed to an outer radial surface. The swab cups 82 may be flexible ring shaped members that restrict flow in one direction along an annulus 36 formed between the logging tool 50 and the wall of the drill string 16 (FIG. 2). The pressure differential associated with this flow restriction generates an axial force that is applied to the sliding sleeve 62. When the logging tool 50 is “pumped down” in the wellbore, the swab cups 82 use this axial force to propel the landing indicator 60 through the drill string 16. After the mandrel 64 of the landing indicator 60 seats on a travel restrictor 26, the swab cups 82 use this axial force to shear the shear screws 70 and slide the sliding sleeve 62 toward the lower section 68. Optionally, a temporary locking element 71 such as a safety pin may be used to prevent relative movement between the sliding sleeve 62 and the mandrel 64 during lifting and handling at the surface. The locking element 71 is removed before the logging tool 50 is tripped into the wellbore 12.

When the sliding sleeve 62 encloses the flow dam 74, the device 54 is in the pre-activated state. When the sliding sleeve 64 slides over the lower section 68 and uncovers the flow dam 74, the landing indicator 60 is in the activated state.

When the landing indicator 60 is in the activated state, the flow dam 74 generates a pressure pulse in the fluid column in the drill string bore 24. In one arrangement, the flow dam 74 may be a pliable umbrella-like element that, when closed, nests within the annular space 72. When activated by a specified pressure or flow rate, the flow dam 74 first unfolds to block or occlude an annular flow space 36 (FIG. 2) between the logging tool 50 and an inner wall of the drill string 24 (FIG. 2). The flow dam 74 may be constructed to maintain structural integrity and resist flow up to a specified value (or collapse value). A fluid pressure or flow rate in excess of the collapse value causes the flow dam 74 to collapse. In one embodiment, the flow dam 74 collapses by inverting, i.e., turning inside out. It should be understood that the flow dam 74 may also collapse by shearing, fragmenting, tearing, or breaking in a manner that reduces the resistance to fluid flow. This reduced resistance causes the pressure in the fluid column to drop. The radial expansion and radial collapse of the flow dam 74 causes a pressure pulse in the drill string bore 24 that travels to the surface. In some embodiments, the flow dam 74 may be formed of a polymer (e.g., rubber) or other similar material that is sufficiently flexible and can deform (e.g., bend or fold) when subjected to fluid pressure. In some embodiments, the flow dam 74 may be constructed in an umbrella-like fashion having a polymeric webbing that is reinforced by rods.

Referring now to FIGS. 1 and 2, in one illustrative operation, the logging tool 50 is inserted into the bore 24 of the drill string 16 after drilling has stopped. A variety of methods may be used to convey and position the logging tool 50 at the target depth. In some embodiments, the tool 50 may free fall through the drill string bore 24 under the effect of primarily gravity. In other embodiments, the logging tool 50 may be propelled using hydraulic pressure. For instance, pumps 34 at the surface may pump drilling fluid into the bore 24 to propel the logging tool 50. In still other embodiments, a combination of gravity and hydraulic pressure may be used to move the logging tool 50 to the target depth.

Once at the target depth, the logging tool 50 will pass through the various discrete stages of activation as shown in FIGS. 3-5. In FIG. 3, the logging tool 50 shown at the target depth and having just made contact with the travel restrictor 26. Because the travel restrictor 26 prevents downward axial movement of the mandrel head 80, the axial loadings induce a shearing stress at the shear screws 70. These axial loadings may be generated by the weight of the logging tool 50 and/or pressurized drilling fluid circulating in the drill string bore 24. At a predetermined value, the shear screws 70 break and release the sliding sleeve 62 from the mandrel 64.

In FIG. 4, the sliding sleeve 62 is shown shifted to the activated position. As noted previously, gravity alone may be used to shift the sliding sleeve 66. In that instance, the mud pumps 34 (FIG. 1) may be operated to pump fluid into the drill string bore 24. If the logging tool 50 had been “pumped down,” then drilling fluid is already flowing in the drill string bore 24. Once the flow dam 74 is exposed to the flowing fluid, the flow dam 74 unfolds and substantially blocks the annular passage 36 of the drill string bore 24. By substantially, it is meant that enough fluid flow is blocked to cause a pressure spike (increase) that can be detected the surface. Thus, personnel monitoring the fluid pressure in the drill string bore 24 will detect an increase in pressure. This pressure reading provides a preliminary indication to personnel that the logging tool 50 may have reached the target depth.

A definitive indication that the logging tool 50 has landed at the target depth may be obtained when the logging tool 50 is in the state shown in FIG. 5. In FIG. 5, the flow dam 74 has inverted due to the fluid flow in the drill string bore 24 (FIG. 2) exceeding the collapse value of the flow dam 74. The webbing of the flow dam 74 is radially compressed such that flow along the annulus 36 is no longer substantially restricted. That is, the flow dam 74 has reduced in cross-sectional size sufficient to cause a pressure drop that can be detected at the surface. Moreover, this pressure drop is of sufficient magnitude as to be uniquely attributed to the collapse of the flow dam 74. The flow dam 74 is shown covering the swab cups 82. However, the swabs 82 can remain exposed in some situations. It should be noted that the contact of the mandrel head 80 with the travel restrictor 26 does not substantially block fluid flow along the drill string bore 24. That is, the travel restrictor 26 may have slots, channels, or other flow passages that allow fluids to flow between the travel restrictor 26 and the mandrel head 80. Thus, fluid circulation may remain substantially the same in the period before and the period after the activation of the landing indicator 60. During activation, the fluid circulation is affected by the pressure pulse as described above.

The combination of a pressure increase due to activation of the flow dam 74 as shown in FIG. 4 and the subsequent pressure drop due to the collapse of the flow dam 74 as shown in FIG. 5 generate a pressure signal that indicates to personnel that the logging tool 50 has landed at the target depth. A variety of flow regimes may be used to expand and collapse the flow dam 74. For instance, the mud pump 34 (FIG. 1) may initiate fluid flow in the drill string bore 24 with a sufficient flow rate/pressure to expand and collapse the flow dam 74. In another regime, the pump 34 may initiate fluid flow with sufficient flow rate/pressure to only expand the flow dam 74. Once a pressure increase is detected, the mud pump 34 (FIG. 1) may be adjusted to increase the flow rate/pressure to collapse the flow dam 74.

Referring now to FIG. 1, the drill string 16 may now be tripped out of the wellbore 12. As the logging tool 50 travels uphole, onboard sensors and related equipment log the well using instruments discussed previously, e.g., gamma ray tools, pulsed neutron tools, etc. As noted previously, the logging tool 50 may be positioned inside the drill string 16. Therefore, the instruments in the sensor section 56 are configured to use techniques that are not impaired by an intervening barrier such as a metal tubular wall. Also, in these embodiments, the logging tool 50 is an “autonomous” tool in that the logging tool 50 is energized and operated using on-board devices and components. After being recovered at the surface, the memory modules of the logging tool 50 are accessed to retrieve the logging information. It should be appreciated that the information obtained by the logging tool 50 can be accurately correlated with the depth along the wellbore 12 because the target depth, which is the depth at which logging started, had been affirmatively established using the landing indicator 60.

It should be understood that the logging tool 50 is susceptible to various modifications and variations. For instance, the travel restrictor 26 may allow axial passage of the mandrel 64 but block passage of the sliding sleeve 62. In that arrangement, the impact of the sliding sleeve 62 against the travel restrictor 26 shears the shear screws 70 and allows the mandrel 64 and flow dam 74 to continue to slide downward. The exposed flow dam 74 then inflates and inverts as previously described. As described previously, one or several methods may be used to shift the sliding sleeve 62. For vertical or deviated wells, gravity may be used to generate an impact force that shifts the sliding sleeve 62. In horizontal wells, the swab cups 82 may be configured to provide enough restriction to provide a significant axial force on the sliding sleeve 62 to break shear screws 70 and slide to uncover the flow dam 74, which inflates and then inverts to generate the pressure signal. In another version,

In the arrangements described above, the logging tool 50 is constructed to function as a “drop tool” (e.g., a ‘go devil’). A “drop tool” is a device that is not tethered to a non-rigid carrier such as a wireline or slickline. However, the logging tool 50 may be constructed as a hybrid “drop tool” in that a non-rigid carrier may be used to guide or control the logging tool 50 until the target depth is reached. The logging tool 50 may include a quick disconnect device that allows the non-rigid carrier to be disconnected and retrieved to the surface before the logging tool 50 is activated. A non-rigid carrier may be a wireline (power and data), an e-line (power only), or a slickline (no power or data). The logging tool 50 may also include other devices such as a shock sub (not shown) to absorb the impact of a hard landing such as when the logging tool 50 is dropped into the wellbore 12.

While the present teachings been discussed in the context of a logging while tripping a tool out of the wellbore, it should be understood that embodiments of the present disclosure may be advantageously applied to other wellbore tools. Such tools may be drilling tools used to form a wellbore, logging tools used to investigate a formation and/or wellbore, or well completion tools. The landing indicators according to the present disclosure may be used to efficiently position one or more of such tools in a wellbore by appropriately positioning the travel restrictor in the wellbore. Moreover, while the present disclosure discusses a hydrocarbon producing well, the present teachings may also be used with other types of wells (e.g., geothermal wells, water wells, etc.) While the foregoing disclosure is directed to the one mode embodiments of the disclosure, various modifications will be apparent to those skilled in the art. It is intended that all variations within the scope of the appended claims be embraced by the foregoing disclosure.

Claims

1. An apparatus for use in a wellbore, comprising:

a tool configured to be conveyed into the wellbore through a drilling tubular;

a landing indicator associated with the tool, the landing indicator being configured to generate a pressure pulse in the drilling tubular after contacting a travel restrictor positioned along the drilling tubular; and

a sensor associated with the tool and configured to estimate at least one selected subsurface parameter while the tool is in the drilling tubular.

2. The apparatus of claim 1, wherein the landing indicator includes a flow dam that selectively restricts fluid flow along a bore of the drilling tubular.

3. The apparatus of claim 2, wherein the flow dam is a pliant member configured to collapse from a radially expanded state when subjected to a specified fluid flow.

4. The apparatus of claim 3, wherein the flow dam is configured to generate a pressure pulse in the bore of the drilling tubular.

5. The apparatus of claim 4, further comprising: a mandrel on which the flow dam is disposed; and a sleeve configured to slide between an first position and a second position on the mandrel, wherein the sleeve at least partially covers the flow dam in the first position.

6. The apparatus of claim 5, wherein the flow dam expands to the radially expanded state after the sleeve slides to the second position.

7. The apparatus of claim 2, wherein the flow dam is configured to invert.

8. The apparatus of claim 1, wherein the landing indicator is connected to the tool to form a drop tool.

9. The apparatus of claim 1, wherein the sensor comprises at least one of: (i) a gamma ray detector, and (ii) a neutron detector.

10. A method of using a tool in a wellbore, comprising:

estimating at least one subsurface parameter using a sensor associated with the tool after receiving at a surface location a pressure pulse generated by a landing indicator associated with the tool, wherein the landing indicator generates the pressure pulse in response to contact with a travel restrictor in a drilling tubular.

11. The method of claim 10, further comprising pumping a drilling fluid into the bore of the drilling tubular, wherein the landing indicator includes a flow dam that is responsive to the flow of the drilling fluid.

12. The method of claim 11, wherein the flow dam responds to the flowing fluid by expanding to a radially expanded state, wherein the radial expansion causes a pressure increase in the flowing fluid.

13. The method of claim 12, further comprising pumping the drilling fluid at a flow parameter selected to collapse the flow dam from the radially expanded state, wherein the collapse causes a pressure decrease in the flowing fluid.

14. The method of claim 13, further comprising detecting at a surface location the pressure increase and the pressure decrease.

15. The method of claim 14, wherein the landing indicator includes a mandrel on which the flow dam is disposed; and a sleeve configured to slide between a first position and a second position on the mandrel, wherein the sleeve at least partially covers the flow dam in the first position, and further comprising moving the sleeve from the first position to the second position after the landing indicator contacts the travel restrictor.

16. The method of claim 15, further comprising circulating fluid in the drilling tubular while the landing indicator contacts the travel restrictor.

17. The method of claim 10, further comprising: tripping the tool out of the wellbore while estimating the at least one subsurface parameter.

18. An apparatus for use in a wellbore, the apparatus comprising:

a tool configured to be conveyed into the wellbore;

a landing indicator associated with the tool, the landing indicator being configured to generate a pressure pulse in a fluid column in the wellbore after contacting a travel restrictor positioned in the wellbore.