Patent Application
20180230767
The present invention relates to drilling of wells for exploration or production of hydrocarbons. More specifically, the invention relates to systems and methods for disengaging a downhole tool from a wall of a wellbore extending into an underground formation, and reducing downhole losses in drilling operations.
Formation evaluation, whether during a wireline operation or while drilling, often requires that fluid from the formation be drawn into a downhole tool for testing and/or sampling. Various sampling devices, typically referred to as probes, are extended from the downhole tool to establish fluid communication with the formation surrounding the wellbore and to draw fluid into the downhole tool. A typical probe is a circular element extended from the downhole tool and positioned against the sidewall of the wellbore. A rubber packer at the end of the probe is used to create a seal with the wellbore sidewall. Another device used to form a seal with the wellbore sidewall is referred to as a dual packer. With a dual packer, two elastomeric rings expand radially about the tool to isolate a portion of the wellbore therebetween. The rings form a seal with the wellbore wall and permit fluid to be drawn into the isolated portion of the wellbore and into an inlet in the downhole tool.
In oil and gas operations, downhole tools (such as wire line tools or drill strings) are conveyed into and withdrawn from the wellbore. Occasionally, during operation, the downhole tool may become stuck in the wellbore. Tool sticking often occurs during formation evaluation procedures, such as coring or formation fluid sampling, where a piston and/or a probe are extended into contact with the mudcake lining the wellbore. Alternatively, a tool may also become stuck during delivery into or removal from the wellbore should it contact with and breach the integrity of the mudcake layer. The formation itself is typically at a relatively lower pressure, while the wellbore is at a relatively higher pressure. Consequently, it is possible for a downhole tool to dislodge a portion of the mudcake layer and expose the tool to a significant pressure differential that holds the tool against the wellbore wall. The holding force generated by the pressure differential is difficult to overcome and often may exceed the force capable of being generated by a backup piston, probe, or other extendible component of the tool. The use of pistons to dislodge a stuck tool is also unsatisfactory because the exact portion of the tool that is in contact with the wall is typically not known, and therefore several pistons spaced circumferentially about the tool must be provided in order to insure that a pushing force can be generated in the appropriate direction. Such pistons can be damaged during tool release operations, preventing their retraction and exacerbating the sticking problem. Other known methods for disengaging downhole tools, such as fishing, cable pulling, and tool pushing by tubing, are overly difficult and time consuming.
In some prior art teachings, a wall-disengaging assembly is carried by a downhole tool, such as the drilling tool 10 of
The downhole drilling tool 10 may be removed from the wellbore and a wireline tool 10′ (
However, none of these tools can be used for smearing a thief zone in a hydrocarbon well, or can strengthen the wellbore to prevent downhole losses, prevent pipe sticking, and improve the hole cleaning process.
Accordingly, one example embodiment of the present disclosure is a downhole tool for use within a wellbore extending into an underground formation. The tool includes a wellbore wall disengaging assembly having a tubular string defining a longitudinal axis, and a plurality of longitudinal blades forming a retractable sleeve around the tubular string, the retractable sleeve having a substantially contiguous inner profile in a closed position, and wherein the retractable sleeve is actuated based on an internal pressure in the tubular string proximate to the downhole tool. In one example embodiment, the retractable sleeve may be mounted in coaxial relation to the tubular string. In one example embodiment, the plurality of longitudinal blades of the retractable sleeve expand to a position with an increased internal diameter when the retractable sleeve is in an open position.
In one example embodiment, the retractable sleeve prevents a flow of a fluid in a lateral direction into the wellbore wall while in an open position, and permits the flow of the fluid in the lateral direction through at least one port in the closed position. In one example embodiment, the retractable sleeve is configured to translate the longitudinal axis of the tubular string away from the wellbore wall in response to rotation of the retractable sleeve relative to the tubular string. The assembly may further include a sensor for sensing pressure on the tubular string, and an actuator for receiving a pressure signal from the sensor and actuating the retractable sleeve. The sensor may be part of a cycling pressure mechanism. The actuator may be configured to move the plurality of longitudinal blades from the closed position to an open position and vice versa. The actuation may be aerodynamic or hydrodynamic in nature. In one example embodiment, the outer surface of the longitudinal blades comprise a smooth or grooved configuration. The tool may be used for smearing a thief zone in a hydrocarbon well, and strengthening the wellbore to prevent downhole losses, pipe sticking, and improving the hole cleaning process.
Another example embodiment is a method of disengaging a downhole tool from a wall of a wellbore extending into an underground formation. The method includes lowering a wellbore wall disengaging assembly, the assembly comprising a tubular string defining a longitudinal axis, and a plurality of longitudinal blades forming a retractable sleeve around the tubular string, the retractable sleeve having a substantially contiguous inner profile in a closed position, and actuating the retractable sleeve based on an internal pressure in the tubular string proximate to the downhole tool. The actuation may be configured to move the plurality of longitudinal blades from the closed position to an open position. In one example embodiment, the plurality of longitudinal blades of the retractable sleeve expand to a position with an increased internal diameter when the retractable sleeve is in an open position. The method may also include preventing a flow of a fluid in a lateral direction into the wellbore wall while in an open position; and permitting the flow of the fluid in the lateral direction through at least one port in the closed position. The method may also include translating the longitudinal axis of the tubular string away from the wellbore wall in response to rotation of the retractable sleeve relative to the tubular string.
In one example embodiment, the wellbore wall disengaging assembly may include a sensor for sensing pressure on the tubular string, and an actuator for receiving a pressure signal from the sensor and actuating the retractable sleeve. The actuation may be aerodynamic or hydrodynamic in nature. The method may also include smearing a thief zone in the hydrocarbon well, and strengthening the wellbore to prevent downhole losses, pipe sticking, and improving the hole cleaning process.
Another example embodiment is a downhole tool for use within a wellbore extending into an underground formation including a wellbore wall disengaging assembly having a tubular string defining a longitudinal axis, and a plurality of longitudinal blades forming a retractable sleeve around the tubular string. The retractable sleeve may have a substantially contiguous inner profile in a first position, and the plurality of longitudinal blades of the retractable sleeve expand to a position with an increased internal diameter when the retractable sleeve is in a second position.
So that the manner in which the features, advantages and objects of the invention, as well as others which may become apparent, are attained and can be understood in more detail, more particular description of the invention briefly summarized above may be had by reference to the embodiment thereof which is illustrated in the appended drawings, which drawings form a part of this specification. It is to be noted, however, that the drawings illustrate only example embodiments of the invention and is therefore not to be considered limiting of its scope as the invention may admit to other equally effective embodiments.
The methods and systems of the present disclosure will now be described more fully hereinafter with reference to the accompanying drawings in which embodiments are shown. The methods and systems of the present disclosure may be in many different forms and should not be construed as limited to the illustrated embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey its scope to those skilled in the art. Like numbers refer to like elements throughout.
Turning now to the figures,
In one example embodiment, the retractable sleeve 214 prevents a flow of a fluid in a lateral direction into the wellbore wall while in an open position, as illustrated in
Another example embodiment is a downhole tool or smart tool for use within a wellbore extending into an underground formation. The tool includes a wellbore wall disengaging assembly having a tubular string defining a longitudinal axis, and a plurality of longitudinal blades forming a retractable sleeve around the tubular string. The retractable sleeve may have a substantially contiguous inner profile in a first position, such as a closed position, and the plurality of longitudinal blades of the retractable sleeve can expand to a position with an increased internal diameter when the retractable sleeve is in a second position, such as an open position, for example.
Referring back to
In one example embodiment, the wellbore wall disengaging assembly 108 may include a sensor assembly 106 for sensing pressure on the tubular string 102, and an actuator 112 for receiving a pressure signal from the sensor 106 and actuating the retractable sleeve 114. The actuation may be aerodynamic or hydrodynamic in nature. The step of actuating the retractable sleeve 114 may enable smearing a thief zone in the hydrocarbon well, and strengthening the wellbore to prevent downhole losses, pipe sticking, and improving the hole cleaning process. Although certain example embodiments disclosed herein refer to the term “actuate” or “actuating” or “actuation,” these terms are synonymous with the terms “activate” or “activating” or “activation,” respectively. Similarly, while translating the tool from a closed position to at least a partially open position may constitute actuation or activation, translating the tool from an at least partially open position to a closed position may constitute “deactivation.”
The primary objective of the example embodiments disclosed herein is to support drilling efforts, to minimize drilling costs, and to improve operation cost effectiveness safely, in the most efficient way. This includes the multi-size interchangeable smart tool 100, 200 to be activated and deactivated as needed for purpose of smearing the thief zones, and enhancing the wellbore strengthening to prevent downhole losses, pipe sticking, and improve the hole cleaning process.
The smart tool or downhole tool 100, 200 can be run in close position and be ready for activation to the recommended size to prevent the losses from happening. Additionally, it can be used in conjunction with wellbore strengthening and lost circulation materials to enhance the efficiency of the system (mud and tool) utilizing a mechanical method and drilling fluids blends. The smart tool or downhole tool 100, 200 can be activated and deactivated on demand during tripping or whenever it may be required.
As oil and gas operators globally strive to enhance drilling efficiency and reduce the cost and non-productive time in the rig, a new way of enhancing the performance of drilling operations is to provide this smart interchangeable design system suitable for smearing the hole. This smart tool has a well-defined characteristics in its design which is retractable for more robust drilling modes. This smart design will allow the operator to control the degree of expansion of the tool to fit the hole size shape and conditions from inside to prevent hole collapse and at the same time can be used as wellbore strengthening mechanical tool to prevent the pipe from getting stuck. The smart tool or downhole tool 100, 200 described in the above example embodiments can be controlled thru mud pulses from the rig floor or at office for safety purpose.
The other advantage is that the smart tool or downhole tool 100, 200 fits different drill pipe standard connections. The smart tool can be used if complete loss of circulation is expected while drilling in surface holes, intermediate, or production hole sections. More complex wells can be drilled using the smart tool to sustain the drilling conditions and serve the purpose on demand since it is durable enough for unexpected events during drilling e.g. fishing, tight holes, etc.
The smart tool or downhole tool 100, 200 of the above example embodiments has hydrodynamics built-in design to activate and prevent differential sticking and could be used as smart mechanical device to free differential sticking and allow to open hole back to original hole size thus eliminating mechanical sticking during drilling. Additionally, the smart tool is designed to be used in all applications in vertical, deviated, and horizontal sections. Importantly, one of the main objective of this tool is that it can enhance the hole cleaning capabilities to allow better cuttings agitation across deviated or horizontal sections in which it can eliminate pipe sticking.
Additionally, the smart tool or downhole tool 100, 200 can provide an optimized smart solution along with drilling fluids to avoid the most chronic challenging hole problems encountered while drilling e.g. pipe sticking, loss circulation, and hole cleaning. This smart tool can also fill the gap in current technologies between fluids and downhole tools. Additional smarter tools such as real-time data acquisition can be linked to extend the functional and effectiveness of the smart tool to cover full range of functionality in order to enhance the drilling performance and reduce the cost.
The Specification, which includes the Summary, Brief Description of the Drawings and the Detailed Description, and the appended Claims refer to particular features (including process or method steps) of the disclosure. Those of skill in the art understand that the invention includes all possible combinations and uses of particular features described in the Specification. Those of skill in the art understand that the disclosure is not limited to or by the description of embodiments given in the Specification.
Those of skill in the art also understand that the terminology used for describing particular embodiments does not limit the scope or breadth of the disclosure. In interpreting the Specification and appended Claims, all terms should be interpreted in the broadest possible manner consistent with the context of each term. All technical and scientific terms used in the Specification and appended Claims have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs unless defined otherwise.
As used in the Specification and appended Claims, the singular forms “a,” “an,” and “the” include plural references unless the context clearly indicates otherwise. The verb “comprises” and its conjugated forms should be interpreted as referring to elements, components or steps in a non-exclusive manner. The referenced elements, components or steps may be present, utilized or combined with other elements, components or steps not expressly referenced.
Conditional language, such as, among others, “can,” “could,” “might,” or “may,” unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain implementations could include, while other implementations do not include, certain features, elements, and/or operations. Thus, such conditional language generally is not intended to imply that features, elements, and/or operations are in any way required for one or more implementations or that one or more implementations necessarily include logic for deciding, with or without user input or prompting, whether these features, elements, and/or operations are included or are to be performed in any particular implementation.
The systems and methods described herein, therefore, are well adapted to carry out the objects and attain the ends and advantages mentioned, as well as others inherent therein. While example embodiments of the system and method have been given for purposes of disclosure, numerous changes exist in the details of procedures for accomplishing the desired results. These and other similar modifications may readily suggest themselves to those skilled in the art, and are intended to be encompassed within the spirit of the system and method disclosed herein and the scope of the appended claims.
