US 20070044959 A1
An apparatus and method for evaluating a formation is presented. The apparatus comprises a tubular string deployed into a wellbore penetrating the formation, where the tubular string has a longitudinal flow passage therethrough. A flow sub in the tubular string provides fluid communication between the longitudinal flow passage in the tubular string and an annulus between the tubular string and a wall of the wellbore. A wireline tool is attached proximate a bottom end of the flow sub. A telemetry module proximate the flow sub provides communication between the wireline tool and a surface system, without the use of a wireline to the surface.
1. An apparatus for evaluating a formation, comprising:
a tubular string deployed into a wellbore penetrating the formation, the tubular string having a longitudinal flow passage therethrough;
a flow sub in the tubular string, said flow sub providing fluid communication between the longitudinal flow passage in the tubular string and an annulus between the tubular string and a wall of the wellbore;
a wireline tool attached proximate a bottom end of the flow sub; and
a telemetry module proximate the flow sub providing communication between the wireline tool and a surface system, without the use of a wireline to the surface.
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12. A method for evaluating a formation, comprising:
deploying a tubular string into a wellbore penetrating the formation;
providing fluid communication between a longitudinal flow passage in the tubular string and an annulus between the tubular string and a wall of the wellbore using a flow sub attached to the tubular string;
measuring a parameter of interest with a wireline tool attached to the tubular string below the flow sub; and
communicating between the wireline tool and a surface system without the use of a wireline.
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1. Field of the Invention
This invention relates generally to logging of subsurface reservoirs and more particularly to pipe conveyed logging.
2. Description of the Related Art
Ordinarily, gravity is used to pull logging tools along and into a well borehole for conducting logging operations. When a well is highly deviated from vertical, the force exerted by gravity may not be sufficient to draw the logging tool through a deviated portion of the well. Many oil wells are deviated. For example, an offshore platform commonly has many wells drilled from the platform into various portions of a targeted formation that surrounds the location of the platform. While some of the wells might be approximately vertical, most of the wells extending from the platform will deviate at various angles into the formations of interest and some may involve deviations up to, or above, horizontal. Gravity conveyed logging tools supported on wirelines lose the effect of gravity for forcing the tool through the hole and simply do not have sufficient motive force to traverse the deviated hole to the zone to be logged. In many instances, the logging tool must be pushed through the deviated well to the zone of interest to ensure that the logging tool is located at the requisite location in the deviated hole. It is desirable therefore that the logging tool be fixed to the end of a string of sufficiently stiff pipe to log along the deviated well at the zone of interest. In many cases, this requires using large pipe, such as drill pipe, to have the stiffness required for logging these sections.
A known method for logging highly deviated wells, disclosed in U.S. Pat. No. 4,457,370, to Wittrisch, consists of the following steps. A well logging tool is secured to the bottom of a section of drill pipe, inside a protective sleeve, and the tool is lowered into the well as additional sections of pipe are assembled. An electrical connector attached to the end of a wireline cable is then inserted into the drill pipe, the cable is passed through a side entry sub mounted on top of the drill string and the connector is pumped down through the drill pipe into engagement with a mating connector attached to the logging tool to effect connection of the tool to the cable and therefore the surface control equipment. Then other sections of drill pipe are added, the portion of the cable above the side entry sub running outside the drill pipe, until the tool reaches the bottom of the section to be logged. Then the logging operation is performed as the drill pipe is moved through the desired section.
The running of the cable and the additional care and complexity required to protect the cable during pipe movement increase the time required to obtain a log. In addition the making of a wet connect is commonly prone to failure requiring additional time and effort to correct.
There is a demonstrated need for providing an apparatus and method for logging a highly deviated wellbore that does not require the running of a wireline cable or the making of a wet connect.
In one aspect of the present invention, an apparatus for evaluating a formation comprises a tubular string deployed into a wellbore penetrating the formation, where the tubular string has a longitudinal flow passage therethrough. A flow sub in the tubular string provides fluid communication between the longitudinal flow passage in the tubular string and an annulus between the tubular string and a wall of the wellbore. A wireline tool is attached proximate a bottom end of the flow sub. A telemetry module proximate the flow sub provides communication between the wireline tool and a surface system, without the use of a wireline to the surface.
In another aspect, a method for evaluating a formation comprises deploying a tubular string into a wellbore penetrating the formation. Fluid communication is provided between a longitudinal flow passage in the tubular string and an annulus between the tubular string and a wall of the wellbore using a flow sub attached to the tubular string. A parameter of interest is measured with a wireline tool attached to the tubular string below the flow sub. Communication between the wireline tool and a surface system is accomplished without the use of a wireline.
For detailed understanding of the present invention, references 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:
As shown, tool 32A is a formation test tool. Logging tool 32B comprises a logging tool that may include, but is not limited to, at least one of: a nuclear magnetic resonance logging tool (NMR); a resistivity tool; and a nuclear density tool. Such tools are used to determine various parameters of interest of the formation including, but not limited to: formation resistivity, formation porosity, and formation permeability. Multiple wireline logging tools may be connected together in a logging string below flow sub 31. It should be noted that there is no significance to the specific location of particular logging tools in the logging string. For example, if multiple wireline tools are connected below flow sub 31, formation test tool 32A may be located at any location in the logging string.
Surface pump 3 pumps fluid 38 through string 13 and down through bottom assembly 30. Fluid 38 exits through flow port 50 in flow sub 31 into the annulus between the string 13 and the wall 14 of borehole 15 where it returns to the surface. While only one flow port 50 is shown, additional ports are located around the circumference of flow sub 31. Energy conductor 51 is disposed within the body of flow sub 31 and enables power and information to be communicated between wireline logging tools 32A and 32B and pulser 53, described below. Alternatively, multiple conductors may be routed in similar fashion.
Fluid 38 provides flow energy to power turbine/alternator 52 (shown in cutaway inside telemetry module 35, and in
Telemetry module 35 also contains oscillating shear valve pulser 53, see
Alternatively, other types of transmission schemes known in the art, that do not employ a wireline connection between the surface and the wireline tool, are intended to be within the scope of the present invention. These include, but are not limited to: acoustic transmission through the pipe wall and electromagnetic telemetry.
In one embodiment, wireline tool 32A is a formation test tool such as those described in U.S. Pat. Nos. 5,303,775; 5,377,755; 5,549,159; 5,587,525; 6,420,869; 6,683,681; 6,798,518; and published application US 2004/0035199 A1, each of which is assigned to the assignee of this application, and each of which is incorporated herein by reference. Anchors 36 and sample probe 34 are extendable from the body of tool 32A to force sample probe 34 into contact with wellbore wall 14 and hence into fluid communication with formation 20. In one embodiment, as illustrated in
In one embodiment, see block diagram in
In one embodiment, surface system 400 contains surface controller 8 that sends commands via downlink pulser 4 to command initiation of various downhole functions, such as, for example performing a formation test. The commands, encoded as pulses 42 are received by a suitable sensor in telemetry module 35, such as for example, a pressure sensor (not separately shown). Once the commands are received and interpreted, downhole controller 405 assumes substantially autonomous control of the formation test. This may include data acquisition and interpretation to determine that a suitable result is obtained. Instructions and decision rules programmed into controller 405 are used to control this operation. Other downlink commands may, for example, cause changes in the encoding and pulsing format to enhance detection at the surface.
While described herein as a system used in a highly deviated wellbore, it is intended that the invention described herein is also to be used for deploying heavy wireline tools, or heavy strings of tools, that may be too heavy to be safely conveyed into and out of wellbores that are not highly deviated, including vertical wellbores.
The foregoing description is directed to particular embodiments of the present invention for the purpose of illustration and explanation. It will be apparent, however, to one skilled in the art that many modifications and changes to the embodiment set forth above are possible. It is intended that the following claims be interpreted to embrace all such modifications and changes.